States rethink 'adult time for adult crime' - the Youth Advocacy Division
States rethink 'adult time for adult crime' - the Youth Advocacy Division
States rethink 'adult time for adult crime' - the Youth Advocacy Division
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<strong>States</strong> <strong>rethink</strong> <strong>'<strong>adult</strong></strong> <strong>time</strong> <strong>for</strong> <strong>adult</strong> <strong>crime'</strong><br />
By Stephanie Chen, CNN<br />
January 15, 2010 7:37 a.m. EST<br />
This month, Connecticut raised from 16 to 17 <strong>the</strong> age <strong>for</strong> juveniles to be automatically<br />
prosecuted in <strong>adult</strong> court.<br />
STORY HIGHLIGHTS<br />
• 16-year-olds who commit crimes in Connecticut no longer automatically treated as <strong>adult</strong>s<br />
• Illinois also stopped sending 17-year-olds who commit misdemeanors to <strong>adult</strong> court<br />
• Sentencing experts say sending juveniles to <strong>the</strong> <strong>adult</strong> system is becoming less popular<br />
• Juveniles sent to <strong>the</strong> <strong>adult</strong> system face criminal records and lack of education<br />
(CNN) -- A year ago, Maydellyn Lamourt watched her 16-year-old son's dreams fall apart.<br />
The outgoing sophomore who enjoyed playing sports was charged and sentenced as an <strong>adult</strong> in<br />
Connecticut <strong>for</strong> third-degree assault.<br />
The crime: He and a friend stole a pack of gum from ano<strong>the</strong>r teen.<br />
Because he entered <strong>the</strong> <strong>adult</strong> penal system, <strong>the</strong> teen's prospects of joining <strong>the</strong> Marines are dim.<br />
His troubles have landed him in an alternative high school.<br />
If Lamourt's son had committed <strong>the</strong> crime this month, his situation would be different. His record<br />
would have been sealed in <strong>the</strong> juvenile system.<br />
Earlier this month, Connecticut raised from 16 to 17 <strong>the</strong> age at which a juvenile is automatically<br />
prosecuted as an <strong>adult</strong>. The change comes at a <strong>time</strong> when <strong>the</strong> "<strong>adult</strong> <strong>time</strong> <strong>for</strong> <strong>adult</strong> crime"<br />
mentality is being re-examined in several states and challenged in <strong>the</strong> U.S. Supreme Court.<br />
Connecticut child advocates say <strong>the</strong> juvenile system is better suited <strong>for</strong> teens because it offers<br />
more access to rehabilitative programs, schooling, community-based programming and
supervision from juvenile probation officers. In felony cases, judges can still decide on a caseby-case<br />
basis whe<strong>the</strong>r to transfer juveniles younger than 17 to <strong>the</strong> <strong>adult</strong> system.<br />
"I was devastated that my son would be in corrections with grown men," said Lamourt. Her son<br />
spent a month at a <strong>adult</strong> facility that housed juveniles and young <strong>adult</strong>s.<br />
"He feels like from here on down, everything will go downhill," she said.<br />
RELATED TOPICS<br />
U.S. map: Juveniles tried as <strong>adult</strong>s<br />
• Juvenile Justice<br />
• Crime<br />
• Criminal Sentencing and Punishment<br />
This year, <strong>the</strong> Supreme Court will consider whe<strong>the</strong>r juvenile offenses merit <strong>adult</strong> punishment.<br />
The justices could decide whe<strong>the</strong>r juveniles can be sentenced to life without parole <strong>for</strong> crimes<br />
o<strong>the</strong>r than murder. One case involves a Florida inmate, who was convicted of rape at <strong>the</strong> age of<br />
13 and given a sentence of life without parole.<br />
Juvenile courts have always had <strong>the</strong> ability to transfer teens and children to <strong>the</strong> <strong>adult</strong> system, but<br />
a spike in youth crime during <strong>the</strong> 1980s and 1990s prompted states to implement mandatory<br />
sentencing policies <strong>for</strong> certain crimes and lower <strong>the</strong> age at which a child can be sentenced to<br />
<strong>adult</strong> court.<br />
Until this year, Connecticut was one of three states, along with New York and North Carolina, to<br />
automatically place teen offenders 16 and older in <strong>the</strong> <strong>adult</strong> system. Ten o<strong>the</strong>r states<br />
automatically transfer juveniles 17 and older to <strong>the</strong> <strong>adult</strong> system -- including South Carolina,<br />
Georgia and Texas.<br />
The decision to raise <strong>the</strong> age of <strong>adult</strong> court jurisdiction in Connecticut was spurred by <strong>the</strong> 2005<br />
suicide of David Burgos. Burgos, a lanky 17-year-old known to family <strong>for</strong> his sense of humor,<br />
suffered from mental illness when he was charged and sentenced as an <strong>adult</strong> <strong>for</strong> violating<br />
probation.<br />
Burgo hung himself with a sheet in his cell at Manson <strong>Youth</strong> Institution, a corrections facility<br />
that also houses offenders between 18 and 21. His suicide galvanized Connecticut lawmakers to<br />
raise <strong>the</strong> age in which a juvenile can be moved into <strong>adult</strong> corrections system.
"When you teach someone to swim, you don't just throw <strong>the</strong>m in <strong>the</strong> deep end and hope <strong>the</strong>y do<br />
great," said Abby Anderson, executive director of <strong>the</strong> Connecticut Juvenile Justice Alliance, <strong>the</strong><br />
nonprofit agency that spearheaded <strong>the</strong> campaign to change <strong>the</strong> law.<br />
When you teach someone to swim, you don't just throw <strong>the</strong>m in <strong>the</strong> deep end and hope <strong>the</strong>y do<br />
great.<br />
--Abby Anderson, executive director, Connecticut Juvenile Justice Alliance<br />
Originally, Connecticut child advocates pushed legislation that raised <strong>the</strong> age to 18, but budget<br />
cuts <strong>for</strong>ced <strong>the</strong> state to raise <strong>the</strong> age to 17.<br />
The policy shift in Connecticut, a state that once sent <strong>the</strong> highest number of juveniles to <strong>the</strong> <strong>adult</strong><br />
system, is catching on in o<strong>the</strong>r states. This month, Illinois stopped sending 17-year-olds who<br />
commit misdemeanors to <strong>the</strong> <strong>adult</strong> system. Instead, <strong>the</strong> offenders are sent to <strong>the</strong> juvenile system<br />
where drug treatment and counseling are often required.<br />
In North Carolina, ano<strong>the</strong>r state where <strong>the</strong> criminal justice system automatically views 16-yearolds<br />
as <strong>adult</strong>s, a bill was introduced last spring to raise <strong>the</strong> age a teen can be charged as an <strong>adult</strong><br />
to 18. That measure in <strong>the</strong> bill was rejected, but lawmakers established a task <strong>for</strong>ce to study <strong>the</strong><br />
proposal with a deadline of 2011.<br />
Meanwhile, lobbying ef<strong>for</strong>ts to raise <strong>the</strong> age continue in o<strong>the</strong>r states. In Georgia and Wisconsin,<br />
where a 17-year-old is considered an <strong>adult</strong>, lawmakers and juvenile advocates have been<br />
working toward change <strong>for</strong> <strong>the</strong> past year.<br />
A precise number of how many children are tried in <strong>adult</strong> court is difficult to ascertain because<br />
states keep records differently, but some experts estimate about a quarter of juveniles are<br />
prosecuted in <strong>the</strong> <strong>adult</strong> court system.<br />
On a single day in 2008, more than 7,700 children younger than 18 were held in <strong>adult</strong> local jails<br />
and 3,600 in <strong>adult</strong> state prisons, according to a 2009 University of Texas-Austin report.<br />
The juvenile system is based on a rehabilitative approach, compared to <strong>the</strong> punitive <strong>adult</strong> system,<br />
child advocates point out. They argue that <strong>the</strong> <strong>adult</strong> system teaches juveniles to become <strong>adult</strong><br />
criminals, which places <strong>the</strong> community at risk.<br />
While some states are questioning <strong>the</strong>ir juvenile sentencing policies, sentencing experts say<br />
raising <strong>the</strong> ages or eliminating mandatory sentences remains politically risky. Much of what<br />
states decide to do with <strong>the</strong>ir juvenile policies may depend upon Connecticut's outcome.<br />
Jeffrey Fagan, a Columbia University law professor who has studied juvenile crime, said he<br />
thinks re<strong>for</strong>m will come in stages, such as Illinois' new law, which addresses juveniles<br />
committing misdemeanors but not o<strong>the</strong>r crimes.<br />
The teenage brain is like a car with a good accelerator but a weak brake.<br />
--Professor Laurence Steinberg, Temple University
"It's easier to sell to <strong>the</strong> public and implement," Fagan said.<br />
The policy changes in Connecticut occurred largely because of a growing body of brain research<br />
distinguishing <strong>the</strong> adolescent and <strong>adult</strong> minds. In 2005, <strong>the</strong> Supreme Court cited differences in<br />
<strong>the</strong> adolescent and <strong>adult</strong> brains as a reason <strong>for</strong> abolishing <strong>the</strong> death penalty <strong>for</strong> juveniles.<br />
Up until <strong>the</strong> last decade, scientific research on <strong>the</strong> adolescent brain was largely nonexistent. Led<br />
by professor Laurence Steinberg of Temple University and o<strong>the</strong>rs in <strong>the</strong> psychology field, <strong>the</strong>ir<br />
research explained why juveniles lack control and understanding of long-term consequence and<br />
are more susceptible to peer pressure.<br />
"The teenage brain is like a car with a good accelerator but a weak brake," Steinberg wrote.<br />
"With powerful impulses under poor control, <strong>the</strong> likely result is a crash."<br />
Critics argue that sending juveniles to <strong>the</strong> <strong>adult</strong> system can deter o<strong>the</strong>r teens. They point out that<br />
juvenile crime has declined in recent years.<br />
Maydellyn Lamourt says she warned her son about <strong>the</strong> dangers of a life of crime, citing mistakes<br />
she had made. Lamourt spent eight months in prison after being convicted of larceny and drug<br />
possession in 2004.<br />
Like her son, <strong>the</strong> mo<strong>the</strong>r knows firsthand <strong>the</strong> consequences of having a criminal record.<br />
"It follows you <strong>for</strong> life," she said.
New York Times<br />
March 11, 2007<br />
The Brain on <strong>the</strong> Stand<br />
By JEFFREY ROSEN<br />
I. Mr. Weinstein’s Cyst When historians of <strong>the</strong> future try to identify <strong>the</strong> moment<br />
that neuroscience began to trans<strong>for</strong>m <strong>the</strong> American legal system, <strong>the</strong>y may point<br />
to a little-noticed case from <strong>the</strong> early 1990s. The case involved Herbert<br />
Weinstein, a 65-year-old ad executive who was charged with strangling his wife,<br />
Barbara, to death and <strong>the</strong>n, in an ef<strong>for</strong>t to make <strong>the</strong> murder look like a suicide,<br />
throwing her body out <strong>the</strong> window of <strong>the</strong>ir 12th-floor apartment on East 72nd<br />
Street in Manhattan. Be<strong>for</strong>e <strong>the</strong> trial began, Weinstein’s lawyer suggested that his<br />
client should not be held responsible <strong>for</strong> his actions because of a mental defect —<br />
namely, an abnormal cyst nestled in his arachnoid membrane, which surrounds<br />
<strong>the</strong> brain like a spider web.<br />
The implications of <strong>the</strong> claim were considerable. American law holds people<br />
criminally responsible unless <strong>the</strong>y act under duress (with a gun pointed at <strong>the</strong><br />
head, <strong>for</strong> example) or if <strong>the</strong>y suffer from a serious defect in rationality — like not<br />
being able to tell right from wrong. But if you suffer from such a serious defect,<br />
<strong>the</strong> law generally doesn’t care why — whe<strong>the</strong>r it’s an unhappy childhood or an<br />
arachnoid cyst or both. To suggest that criminals could be excused because <strong>the</strong>ir<br />
brains made <strong>the</strong>m do it seems to imply that anyone whose brain isn’t functioning<br />
properly could be absolved of responsibility. But should judges and juries really<br />
be in <strong>the</strong> business of defining <strong>the</strong> normal or properly working brain And since all<br />
behavior is caused by our brains, wouldn’t this mean all behavior could<br />
potentially be excused<br />
The prosecution at first tried to argue that evidence of Weinstein’s arachnoid cyst<br />
shouldn’t be admitted in court. One of <strong>the</strong> government’s witnesses, a <strong>for</strong>ensic<br />
psychologist named Daniel Martell, testified that brain-scanning technologies<br />
were new and untested, and <strong>the</strong>ir implications weren’t yet widely accepted by <strong>the</strong><br />
scientific community. Ultimately, on Oct. 8, 1992, Judge Richard Carru<strong>the</strong>rs<br />
issued a Solomonic ruling: Weinstein’s lawyers could tell <strong>the</strong> jury that brain scans<br />
had identified an arachnoid cyst, but <strong>the</strong>y couldn’t tell jurors that arachnoid cysts<br />
were associated with violence. Even so, <strong>the</strong> prosecution team seemed to fear that
simply exhibiting images of Weinstein’s brain in court would sway <strong>the</strong> jury.<br />
Eleven days later, on <strong>the</strong> morning of jury selection, <strong>the</strong>y agreed to let Weinstein<br />
plead guilty in exchange <strong>for</strong> a reduced charge of manslaughter.<br />
After <strong>the</strong> Weinstein case, Daniel Martell found himself in so much demand to<br />
testify as a expert witness that he started a consulting business called Forensic<br />
Neuroscience. Hired by defense teams and prosecutors alike, he has testified over<br />
<strong>the</strong> past 15 years in several hundred criminal and civil cases. In those cases,<br />
neuroscientific evidence has been admitted to show everything from head trauma<br />
to <strong>the</strong> tendency of violent video games to make children behave aggressively. But<br />
Martell told me that it’s in death-penalty litigation that neuroscience evidence is<br />
having its most revolutionary effect. “Some sort of organic brain defense has<br />
become de rigueur in any sort of capital defense,” he said. Lawyers routinely<br />
order scans of convicted defendants’ brains and argue that a neurological<br />
impairment prevented <strong>the</strong>m from controlling <strong>the</strong>mselves. The prosecution<br />
counters that <strong>the</strong> evidence shouldn’t be admitted, but under <strong>the</strong> relaxed<br />
standards <strong>for</strong> mitigating evidence during capital sentencing, it usually is. Indeed,<br />
a Florida court has held that <strong>the</strong> failure to admit neuroscience evidence during<br />
capital sentencing is grounds <strong>for</strong> a reversal. Martell remains skeptical about <strong>the</strong><br />
worth of <strong>the</strong> brain scans, but he observes that <strong>the</strong>y’ve “revolutionized <strong>the</strong> law.”<br />
The extent of that revolution is hotly debated, but <strong>the</strong> influence of what some call<br />
neurolaw is clearly growing. Neuroscientific evidence has persuaded jurors to<br />
sentence defendants to life imprisonment ra<strong>the</strong>r than to death; courts have also<br />
admitted brain-imaging evidence during criminal trials to support claims that<br />
defendants like John W. Hinckley Jr., who tried to assassinate President Reagan,<br />
are insane. Carter Snead, a law professor at Notre Dame, drafted a staff working<br />
paper on <strong>the</strong> impact of neuroscientific evidence in criminal law <strong>for</strong> President<br />
Bush’s Council on Bioethics. The report concludes that neuroimaging evidence is<br />
of mixed reliability but “<strong>the</strong> large number of cases in which such evidence is<br />
presented is striking.” That number will no doubt increase substantially.<br />
Proponents of neurolaw say that neuroscientific evidence will have a large impact<br />
not only on questions of guilt and punishment but also on <strong>the</strong> detection of lies<br />
and hidden bias, and on <strong>the</strong> prediction of future criminal behavior. At <strong>the</strong> same<br />
<strong>time</strong>, skeptics fear that <strong>the</strong> use of brain-scanning technology as a kind of super
mind-reading device will threaten our privacy and mental freedom, leading some<br />
to call <strong>for</strong> <strong>the</strong> legal system to respond with a new concept of “cognitive liberty.”<br />
One of <strong>the</strong> most enthusiastic proponents of neurolaw is Owen Jones, a professor<br />
of law and biology at Vanderbilt. Jones (who happens to have been one of my<br />
law-school classmates) has joined a group of prominent neuroscientists and law<br />
professors who have applied <strong>for</strong> a large MacArthur Foundation grant; <strong>the</strong>y hope<br />
to study a wide range of neurolaw questions, like: Do sexual offenders and violent<br />
teenagers show unusual patterns of brain activity Is it possible to capture brain<br />
images of chronic neck pain when someone claims to have suffered whiplash In<br />
<strong>the</strong> mean<strong>time</strong>, Jones is turning Vanderbilt into a kind of Los Alamos <strong>for</strong><br />
neurolaw. The university has just opened a $27 million neuroimaging center and<br />
has poached leading neuroscientists from around <strong>the</strong> world; soon, Jones hopes to<br />
enroll students in <strong>the</strong> nation’s first program in law and neuroscience. “It’s<br />
breathlessly exciting,” he says. “This is <strong>the</strong> new frontier in law and science —<br />
we’re peering into <strong>the</strong> black box to see how <strong>the</strong> brain is actually working, that<br />
hidden place in <strong>the</strong> dark quiet, where we have our private thoughts and private<br />
reactions — and <strong>the</strong> law will inevitably have to decide how to deal with this new<br />
technology.”<br />
II. A Visit to Vanderbilt Owen Jones is a disciplined and quietly intense man, and<br />
his enthusiasm <strong>for</strong> <strong>the</strong> trans<strong>for</strong>mative power of neuroscience is infectious. With<br />
René Marois, a neuroscientist in <strong>the</strong> psychology department, Jones has begun a<br />
study of how <strong>the</strong> human brain reacts when asked to impose various punishments.<br />
In<strong>for</strong>mally, <strong>the</strong>y call <strong>the</strong> experiment Harm and Punishment — and <strong>the</strong>y offered to<br />
make me one of <strong>the</strong>ir first subjects.<br />
We met in Jones’s pristine office, which is decorated with a human skull and<br />
calipers, like those that phrenologists once used to measure <strong>the</strong> human head; his<br />
fa<strong>the</strong>r is a dentist, and his grandfa<strong>the</strong>r was an electrical engineer who collected<br />
tools. We walked over to Vanderbilt’s Institute of Imaging Science, which,<br />
although still surrounded by scaffolding, was as impressive as Jones had<br />
promised. The basement contains one of <strong>the</strong> few 7-tesla magnetic-resonanceimaging<br />
scanners in <strong>the</strong> world. For Harm and Punishment, Jones and Marois use<br />
a less powerful 3 tesla, which is <strong>the</strong> typical research M.R.I.
We <strong>the</strong>n made our way to <strong>the</strong> scanner. After removing all metal objects —<br />
including a belt and a stray dry-cleaning tag with a staple — I put on earphones<br />
and a helmet that was shaped like a birdcage to hold my head in place. The lab<br />
assistant turned off <strong>the</strong> lights and left <strong>the</strong> room; I lay down on <strong>the</strong> gurney and,<br />
clutching a panic button, was inserted into <strong>the</strong> magnet. All was dark except <strong>for</strong> a<br />
screen flashing hypo<strong>the</strong>tical crime scenarios, like this one: “John, who lives at<br />
home with his fa<strong>the</strong>r, decides to kill him <strong>for</strong> <strong>the</strong> insurance money. After<br />
convincing his fa<strong>the</strong>r to help with some electrical work in <strong>the</strong> attic, John arranges<br />
<strong>for</strong> him to be electrocuted. His fa<strong>the</strong>r survives <strong>the</strong> electrocution, but he is<br />
hospitalized <strong>for</strong> three days with injuries caused by <strong>the</strong> electrical shock.” I was told<br />
to press buttons indicating <strong>the</strong> appropriate level of punishment, from 0 to 9, as<br />
<strong>the</strong> magnet recorded my brain activity.<br />
After I spent 45 minutes trying not to move an eyebrow while assigning<br />
punishments to dozens of sordid imaginary criminals, Marois told me through<br />
<strong>the</strong> intercom to try ano<strong>the</strong>r experiment: namely, to think of familiar faces and<br />
places in sequence, without telling him whe<strong>the</strong>r I was starting with faces or<br />
places. I thought of my living room, my wife, my parents’ apartment and my twin<br />
sons, trying all <strong>the</strong> while to avoid improper thoughts <strong>for</strong> fear <strong>the</strong>y would be<br />
discovered. Then <strong>the</strong> experiments were over, and I stumbled out of <strong>the</strong> magnet.<br />
The next morning, Owen Jones and I reported to René Marois’s laboratory <strong>for</strong><br />
<strong>the</strong> results. Marois’s graduate students, who had been up late analyzing my brain,<br />
were smiling broadly. Because I had moved so little in <strong>the</strong> machine, <strong>the</strong>y<br />
explained, my brain activity was easy to read. “Your head movement was<br />
incredibly low, and you were <strong>the</strong> harshest punisher we’ve had,” Josh Buckholtz,<br />
one of <strong>the</strong> grad students, said with a happy laugh. “You were a researcher’s dream<br />
come true!” Buckholtz tapped <strong>the</strong> keyboard, and a high-resolution 3-D image of<br />
my brain appeared on <strong>the</strong> screen in vivid colors. Tiny dots flickered back and<br />
<strong>for</strong>th, showing my eyes moving as <strong>the</strong>y read <strong>the</strong> lurid criminal scenarios.<br />
Although I was only <strong>the</strong> fifth subject to be put in <strong>the</strong> scanner, Marois emphasized<br />
that my punishment ratings were higher than average. In one case, I assigned a 7<br />
where <strong>the</strong> average punishment was 4. “You were focusing on <strong>the</strong> intent, and <strong>the</strong><br />
o<strong>the</strong>rs focused on <strong>the</strong> harm,” Buckholtz said reassuringly.
Marois explained that he and Jones wanted to study <strong>the</strong> interactions among <strong>the</strong><br />
emotion-generating regions of <strong>the</strong> brain, like <strong>the</strong> amygdala, and <strong>the</strong> prefrontal<br />
regions responsible <strong>for</strong> reason. “It is also possible that <strong>the</strong> prefrontal cortex is<br />
critical <strong>for</strong> attributing punishment, making <strong>the</strong> essential decision about what<br />
kind of punishment to assign,” he suggested. Marois stressed that in order to<br />
study that possibility, more subjects would have to be put into <strong>the</strong> magnet. But if<br />
<strong>the</strong> prefrontal cortex does turn out to be critical <strong>for</strong> selecting among<br />
punishments, Jones added, it could be highly relevant <strong>for</strong> lawyers selecting a jury.<br />
For example, he suggested, lawyers might even select jurors <strong>for</strong> different cases<br />
based on <strong>the</strong>ir different brain-activity patterns. In a complex insider-trading case,<br />
<strong>for</strong> example, perhaps <strong>the</strong> defense would “like to have a juror making decisions on<br />
maximum deliberation and minimum emotion”; in a government entrapment<br />
case, emotional reactions might be more appropriate.<br />
We <strong>the</strong>n turned to <strong>the</strong> results of <strong>the</strong> second experiment, in which I had been<br />
asked to alternate between thinking of faces and places without disclosing <strong>the</strong><br />
order. “We think we can guess what you were thinking about, even though you<br />
didn’t tell us <strong>the</strong> order you started with,” Marois said proudly. “We think you<br />
started with places and we will prove to you that it wasn’t just luck.” Marois<br />
showed me a picture of my parahippocampus, <strong>the</strong> area of <strong>the</strong> brain that responds<br />
strongly to places and <strong>the</strong> recognition of scenes. “It’s lighting up like Christmas<br />
on all cylinders,” Marois said. “It worked beautifully, even though we haven’t<br />
tried this be<strong>for</strong>e here.”<br />
He <strong>the</strong>n showed a picture of <strong>the</strong> fusi<strong>for</strong>m area, which is responsible <strong>for</strong> facial<br />
recognition. It, too, lighted up every <strong>time</strong> I thought of a face. “This is a potentially<br />
very serious legal implication,” Jones broke in, since <strong>the</strong> technology allows us to<br />
tell what people are thinking about even if <strong>the</strong>y deny it. He pointed to a series of<br />
practical applications. Because subconscious memories of faces and places may<br />
be more reliable than conscious memories, witness lineups could be trans<strong>for</strong>med.<br />
A child who claimed to have been victimized by a stranger, moreover, could be<br />
shown pictures of <strong>the</strong> faces of suspects to see which one lighted up <strong>the</strong> facerecognition<br />
area in ways suggesting familiarity.<br />
Jones and Marois talked excitedly about <strong>the</strong> implications of <strong>the</strong>ir experiments <strong>for</strong><br />
<strong>the</strong> legal system. If <strong>the</strong>y discovered a significant gap between people’s hard-wired
sense of how severely certain crimes should be punished and <strong>the</strong> actual<br />
punishments assigned by law, federal sentencing guidelines might be revised, on<br />
<strong>the</strong> principle that <strong>the</strong> law shouldn’t diverge too far from deeply shared beliefs.<br />
Experiments might help to develop a deeper understanding of <strong>the</strong> criminal brain,<br />
or of <strong>the</strong> typical brain predisposed to criminal activity.<br />
III. The End of Responsibility Indeed, as <strong>the</strong> use of functional M.R.I. results<br />
becomes increasingly common in courtrooms, judges and juries may be asked to<br />
draw new and some<strong>time</strong>s troubling lines between “normal” and “abnormal”<br />
brains. Ruben Gur, a professor of psychology at <strong>the</strong> University of Pennsylvania<br />
School of Medicine, specializes in doing just that. Gur began his expert-witness<br />
career in <strong>the</strong> mid-1990s when a colleague asked him to help in <strong>the</strong> trial of a<br />
convicted serial killer in Florida named Bobby Joe Long. Known as <strong>the</strong><br />
“classified-ad rapist,” because he would respond to classified ads placed by<br />
women offering to sell household items, <strong>the</strong>n rape and kill <strong>the</strong>m, Long was<br />
sentenced to death after he committed at least nine murders in Tampa. Gur was<br />
called as a national expert in positron-emission tomography, or PET scans, in<br />
which patients are injected with a solution containing radioactive markers that<br />
illuminate <strong>the</strong>ir brain activity. After examining Long’s PET scans, Gur testified<br />
that a motorcycle accident that had left Long in a coma had also severely<br />
damaged his amygdala. It was after emerging from <strong>the</strong> coma that Long<br />
committed his first rape.<br />
“I didn’t have <strong>the</strong> sense that my testimony had a profound impact,” Gur told me<br />
recently — Long is still filing appeals — but he has testified at more than 20<br />
capital cases since <strong>the</strong>n. He wrote a widely circulated affidavit arguing that<br />
adolescents are not as capable of controlling <strong>the</strong>ir impulses as <strong>adult</strong>s because <strong>the</strong><br />
development of neurons in <strong>the</strong> prefrontal cortex isn’t complete until <strong>the</strong> early<br />
20s. Based on that affidavit, Gur was asked to contribute to <strong>the</strong> preparation of<br />
one of <strong>the</strong> briefs filed by neuroscientists and o<strong>the</strong>rs in Roper v. Simmons, <strong>the</strong><br />
landmark case in which a divided Supreme Court struck down <strong>the</strong> death penalty<br />
<strong>for</strong> offenders who committed crimes when <strong>the</strong>y were under <strong>the</strong> age of 18.<br />
The leading neurolaw brief in <strong>the</strong> case, filed by <strong>the</strong> American Medical Association<br />
and o<strong>the</strong>r groups, argued that because “adolescent brains are not fully developed”<br />
in <strong>the</strong> prefrontal regions, adolescents are less able than <strong>adult</strong>s to control <strong>the</strong>ir
impulses and should not be held fully accountable “<strong>for</strong> <strong>the</strong> immaturity of <strong>the</strong>ir<br />
neural anatomy.” In his majority decision, Justice Anthony Kennedy declared<br />
that “as any parent knows and as <strong>the</strong> scientific and sociological studies” cited in<br />
<strong>the</strong> briefs “tend to confirm, ‘[a] lack of maturity and an underdeveloped sense of<br />
responsibility are found in youth more often than in <strong>adult</strong>s.’ ” Although Kennedy<br />
did not cite <strong>the</strong> neuroscience evidence specifically, his indirect reference to <strong>the</strong><br />
scientific studies in <strong>the</strong> briefs led some supporters and critics to view <strong>the</strong> decision<br />
as <strong>the</strong> Brown v. Board of Education of neurolaw.<br />
One important question raised by <strong>the</strong> Roper case was <strong>the</strong> question of where to<br />
draw <strong>the</strong> line in considering neuroscience evidence as a legal mitigation or<br />
excuse. Should courts be in <strong>the</strong> business of deciding when to mitigate someone’s<br />
criminal responsibility because his brain functions improperly, whe<strong>the</strong>r because<br />
of age, in-born defects or trauma As we learn more about criminals’ brains, will<br />
we have to redefine our most basic ideas of justice<br />
Two of <strong>the</strong> most ardent supporters of <strong>the</strong> claim that neuroscience requires <strong>the</strong><br />
redefinition of guilt and punishment are Joshua D. Greene, an assistant professor<br />
of psychology at Harvard, and Jonathan D. Cohen, a professor of psychology who<br />
directs <strong>the</strong> neuroscience program at Princeton. Greene got Cohen interested in<br />
<strong>the</strong> legal implications of neuroscience, and toge<strong>the</strong>r <strong>the</strong>y conducted a series of<br />
experiments exploring how people’s brains react to moral dilemmas involving life<br />
and death. In particular, <strong>the</strong>y wanted to test people’s responses in <strong>the</strong> f.M.R.I.<br />
scanner to variations of <strong>the</strong> famous trolley problem, which philosophers have<br />
been arguing about <strong>for</strong> decades.<br />
The trolley problem goes something like this: Imagine a train heading toward five<br />
people who are going to die if you don’t do anything. If you hit a switch, <strong>the</strong> train<br />
veers onto a side track and kills ano<strong>the</strong>r person. Most people confronted with this<br />
scenario say it’s O.K. to hit <strong>the</strong> switch. By contrast, imagine that you’re standing<br />
on a footbridge that spans <strong>the</strong> train tracks, and <strong>the</strong> only way you can save <strong>the</strong> five<br />
people is to push an obese man standing next to you off <strong>the</strong> footbridge so that his<br />
body stops <strong>the</strong> train. Under <strong>the</strong>se circumstances, most people say it’s not O.K. to<br />
kill one person to save five.
“I wondered why people have such clear intuitions,” Greene told me, “and <strong>the</strong><br />
core idea was to confront people with <strong>the</strong>se two cases in <strong>the</strong> scanner and see if we<br />
got more of an emotional response in one case and reasoned response in <strong>the</strong><br />
o<strong>the</strong>r.” As it turns out, that’s precisely what happened: Greene and Cohen found<br />
that <strong>the</strong> brain region associated with deliberate problem solving and self-control,<br />
<strong>the</strong> dorsolateral prefrontal cortex, was especially active when subjects confronted<br />
<strong>the</strong> first trolley hypo<strong>the</strong>tical, in which most of <strong>the</strong>m made a utilitarian judgment<br />
about how to save <strong>the</strong> greatest number of lives. By contrast, emotional centers in<br />
<strong>the</strong> brain were more active when subjects confronted <strong>the</strong> second trolley<br />
hypo<strong>the</strong>tical, in which <strong>the</strong>y tended to recoil at <strong>the</strong> idea of personally harming an<br />
individual, even under such wrenching circumstances. “This suggests that moral<br />
judgment is not a single thing; it’s intuitive emotional responses and <strong>the</strong>n<br />
cognitive responses that are duking it out,” Greene said.<br />
“To a neuroscientist, you are your brain; nothing causes your behavior o<strong>the</strong>r than<br />
<strong>the</strong> operations of your brain,” Greene says. “If that’s right, it radically changes <strong>the</strong><br />
way we think about <strong>the</strong> law. The official line in <strong>the</strong> law is all that matters is<br />
whe<strong>the</strong>r you’re rational, but you can have someone who is totally rational but<br />
whose strings are being pulled by something beyond his control.” In o<strong>the</strong>r words,<br />
even someone who has <strong>the</strong> illusion of making a free and rational choice between<br />
soup and salad may be deluding himself, since <strong>the</strong> choice of salad over soup is<br />
ultimately predestined by <strong>for</strong>ces hard-wired in his brain. Greene insists that this<br />
insight means that <strong>the</strong> criminal-justice system should abandon <strong>the</strong> idea of<br />
retribution — <strong>the</strong> idea that bad people should be punished because <strong>the</strong>y have<br />
freely chosen to act immorally — which has been <strong>the</strong> focus of American criminal<br />
law since <strong>the</strong> 1970s, when rehabilitation went out of fashion. Instead, Greene<br />
says, <strong>the</strong> law should focus on deterring future harms. In some cases, he supposes,<br />
this might mean lighter punishments. “If it’s really true that we don’t get any<br />
prevention bang from our punishment buck when we punish that person, <strong>the</strong>n<br />
it’s not worth punishing that person,” he says. (On <strong>the</strong> o<strong>the</strong>r hand, Carter Snead,<br />
<strong>the</strong> Notre Dame scholar, maintains that capital defendants who are not<br />
considered fully blameworthy under current rules could be executed more readily<br />
under a system that focused on preventing future harms.)<br />
O<strong>the</strong>rs agree with Greene and Cohen that <strong>the</strong> legal system should be radically<br />
refocused on deterrence ra<strong>the</strong>r than on retribution. Since <strong>the</strong> celebrated
M’Naughten case in 1843, involving a paranoid British assassin, English and<br />
American courts have recognized an insanity defense only <strong>for</strong> those who are<br />
unable to appreciate <strong>the</strong> difference between right and wrong. (This is consistent<br />
with <strong>the</strong> idea that only rational people can be held criminally responsible <strong>for</strong> <strong>the</strong>ir<br />
actions.) According to some neuroscientists, that rule makes no sense in light of<br />
recent brain-imaging studies. “You can have a horrendously damaged brain<br />
where someone knows <strong>the</strong> difference between right and wrong but none<strong>the</strong>less<br />
can’t control <strong>the</strong>ir behavior,” says Robert Sapolsky, a neurobiologist at Stan<strong>for</strong>d.<br />
“At that point, you’re dealing with a broken machine, and concepts like<br />
punishment and evil and sin become utterly irrelevant. Does that mean <strong>the</strong><br />
person should be dumped back on <strong>the</strong> street Absolutely not. You have a car with<br />
<strong>the</strong> brakes not working, and it shouldn’t be allowed to be near anyone it can<br />
hurt.”<br />
Even as <strong>the</strong>se debates continue, some skeptics contend that both <strong>the</strong> hopes and<br />
fears attached to neurolaw are overblown. “There’s nothing new about <strong>the</strong><br />
neuroscience ideas of responsibility; it’s just ano<strong>the</strong>r material, causal explanation<br />
of human behavior,” says Stephen J. Morse, professor of law and psychiatry at<br />
<strong>the</strong> University of Pennsylvania. “How is this different than <strong>the</strong> Chicago school of<br />
sociology,” which tried to explain human behavior in terms of environment and<br />
social structures “How is it different from genetic explanations or psychological<br />
explanations The only thing different about neuroscience is that we have prettier<br />
pictures and it appears more scientific.”<br />
Morse insists that “brains do not commit crimes; people commit crimes” — a<br />
conclusion he suggests has been ignored by advocates who, “infected and<br />
inflamed by stunning advances in our understanding of <strong>the</strong> brain . . . all too often<br />
make moral and legal claims that <strong>the</strong> new neuroscience . . . cannot sustain.” He<br />
calls this “brain overclaim syndrome” and cites as an example <strong>the</strong> neuroscience<br />
briefs filed in <strong>the</strong> Supreme Court case Roper v. Simmons to question <strong>the</strong> juvenile<br />
death penalty. “What did <strong>the</strong> neuroscience add” he asks. If adolescent brains<br />
caused all adolescent behavior, “we would expect <strong>the</strong> rates of homicide to be <strong>the</strong><br />
same <strong>for</strong> 16- and 17-year-olds everywhere in <strong>the</strong> world — <strong>the</strong>ir brains are alike —<br />
but in fact, <strong>the</strong> homicide rates of Danish and Finnish youths are very different<br />
than American youths.” Morse agrees that our brains bring about our behavior —<br />
“I’m a thoroughgoing materialist, who believes that all mental and behavioral
activity is <strong>the</strong> causal product of physical events in <strong>the</strong> brain” — but he disagrees<br />
that <strong>the</strong> law should excuse certain kinds of criminal conduct as a result. “It’s a<br />
total non sequitur,” he says. “So what if <strong>the</strong>re’s biological causation Causation<br />
can’t be an excuse <strong>for</strong> someone who believes that responsibility is possible. Since<br />
all behavior is caused, this would mean all behavior has to be excused.” Morse<br />
cites <strong>the</strong> case of Charles Whitman, a man who, in 1966, killed his wife and his<br />
mo<strong>the</strong>r, <strong>the</strong>n climbed up a tower at <strong>the</strong> University of Texas and shot and killed 13<br />
more people be<strong>for</strong>e being shot by police officers. Whitman was discovered after<br />
an autopsy to have a tumor that was putting pressure on his amygdala. “Even if<br />
his amygdala made him more angry and volatile, since when are anger and<br />
volatility excusing conditions” Morse asks. “Some people are angry because <strong>the</strong>y<br />
had bad mommies and daddies and o<strong>the</strong>rs because <strong>the</strong>ir amygdalas are mucked<br />
up. The question is: When should anger be an excusing condition”<br />
Still, Morse concedes that <strong>the</strong>re are circumstances under which new discoveries<br />
from neuroscience could challenge <strong>the</strong> legal system at its core. “Suppose<br />
neuroscience could reveal that reason actually plays no role in determining<br />
human behavior,” he suggests tantalizingly. “Suppose I could show you that your<br />
intentions and your reasons <strong>for</strong> your actions are post hoc rationalizations that<br />
somehow your brain generates to explain to you what your brain has already<br />
done” without your conscious participation. If neuroscience could reveal us to be<br />
automatons in this respect, Morse is prepared to agree with Greene and Cohen<br />
that criminal law would have to abandon its current ideas about responsibility<br />
and seek o<strong>the</strong>r ways of protecting society.<br />
Some scientists are already pushing in this direction. In a series of famous<br />
experiments in <strong>the</strong> 1970s and ’80s, Benjamin Libet measured people’s brain<br />
activity while telling <strong>the</strong>m to move <strong>the</strong>ir fingers whenever <strong>the</strong>y felt like it. Libet<br />
detected brain activity suggesting a readiness to move <strong>the</strong> finger half a second<br />
be<strong>for</strong>e <strong>the</strong> actual movement and about 400 milliseconds be<strong>for</strong>e people became<br />
aware of <strong>the</strong>ir conscious intention to move <strong>the</strong>ir finger. Libet argued that this<br />
leaves 100 milliseconds <strong>for</strong> <strong>the</strong> conscious self to veto <strong>the</strong> brain’s unconscious<br />
decision, or to give way to it — suggesting, in <strong>the</strong> words of <strong>the</strong> neuroscientist<br />
Vilayanur S. Ramachandran, that we have not free will but “free won’t.”
Morse is not convinced that <strong>the</strong> Libet experiments reveal us to be helpless<br />
automatons. But he does think that <strong>the</strong> study of our decision-making powers<br />
could bear some fruit <strong>for</strong> <strong>the</strong> law. “I’m interested,” he says, “in people who suffer<br />
from drug addictions, psychopaths and people who have intermittent explosive<br />
disorder — that’s people who have no general rationality problem o<strong>the</strong>r than <strong>the</strong>y<br />
just go off.” In o<strong>the</strong>r words, Morse wants to identify <strong>the</strong> neural triggers that make<br />
people go postal. “Suppose we could show that <strong>the</strong> higher deliberative centers in<br />
<strong>the</strong> brain seem to be disabled in <strong>the</strong>se cases,” he says. “If <strong>the</strong>se are people who<br />
cannot control episodes of gross irrationality, we’ve learned something that might<br />
be relevant to <strong>the</strong> legal ascription of responsibility.” That doesn’t mean <strong>the</strong>y<br />
would be let off <strong>the</strong> hook, he emphasizes: “You could give people a prison<br />
sentence and an opportunity to get fixed.”<br />
IV. Putting <strong>the</strong> Unconscious on Trial If debates over criminal responsibility long<br />
predate <strong>the</strong> f.M.R.I., so do debates over <strong>the</strong> use of lie-detection technology.<br />
What’s new is <strong>the</strong> prospect that lie detectors in <strong>the</strong> courtroom will become much<br />
more accurate, and correspondingly more intrusive. There are, at <strong>the</strong> moment,<br />
two lie-detection technologies that rely on neuroimaging, although <strong>the</strong> value and<br />
accuracy of both are sharply contested. The first, developed by Lawrence Farwell<br />
in <strong>the</strong> 1980s, is known as “brain fingerprinting.” Subjects put on an electrodefilled<br />
helmet that measures a brain wave called p300, which, according to<br />
Farwell, changes its frequency when people recognize images, pictures, sights and<br />
smells. After showing a suspect pictures of familiar places and measuring his<br />
p300 activation patterns, government officials could, at least in <strong>the</strong>ory, show a<br />
suspect pictures of places he may or may not have seen be<strong>for</strong>e — a Qaeda training<br />
camp, <strong>for</strong> example, or a crime scene — and compare <strong>the</strong> activation patterns. (By<br />
detecting not only lies but also honest cases of <strong>for</strong>getfulness, <strong>the</strong> technology could<br />
expand our very idea of lie detection.)<br />
The second lie-detection technology uses f.M.R.I. machines to compare <strong>the</strong> brain<br />
activity of liars and truth tellers. It is based on a test called Guilty Knowledge,<br />
developed by Daniel Langleben at <strong>the</strong> University of Pennsylvania in 2001.<br />
Langleben gave subjects a playing card be<strong>for</strong>e <strong>the</strong>y entered <strong>the</strong> magnet and told<br />
<strong>the</strong>m to answer no to a series of questions, including whe<strong>the</strong>r <strong>the</strong>y had <strong>the</strong> card in<br />
question. Langleben and his colleagues found that certain areas of <strong>the</strong> brain<br />
lighted up when people lied.
Two companies, No Lie MRI and Cephos, are now competing to refine f.M.R.I.<br />
lie-detection technology so that it can be admitted in court and commercially<br />
marketed. I talked to Steven Laken, <strong>the</strong> president of Cephos, which plans to begin<br />
selling its products this year. “We have two to three people who call every single<br />
week,” he told me. “They’re in legal proceedings throughout <strong>the</strong> world, and<br />
<strong>the</strong>y’re looking to bolster <strong>the</strong>ir credibility.” Laken said <strong>the</strong> technology could have<br />
“tremendous applications” in civil and criminal cases. On <strong>the</strong> government side,<br />
he said, <strong>the</strong> technology could replace highly inaccurate polygraphs in screening<br />
<strong>for</strong> security clearances, as well as in trying to identify suspected terrorists’ native<br />
languages and close associates. “In lab studies, we’ve been in <strong>the</strong> 80- to 90-<br />
percent-accuracy range,” Laken says. This is similar to <strong>the</strong> accuracy rate <strong>for</strong><br />
polygraphs, which are not considered sufficiently reliable to be allowed in most<br />
legal cases. Laken says he hopes to reach <strong>the</strong> 90-percent- to 95-percent-accuracy<br />
range — which should be high enough to satisfy <strong>the</strong> Supreme Court’s standards<br />
<strong>for</strong> <strong>the</strong> admission of scientific evidence. Judy Illes, director of Neuroethics at <strong>the</strong><br />
Stan<strong>for</strong>d Center <strong>for</strong> Biomedical Ethics, says, “I would predict that within five<br />
years, we will have technology that is sufficiently reliable at getting at <strong>the</strong> binary<br />
question of whe<strong>the</strong>r someone is lying that it may be utilized in certain legal<br />
settings.”<br />
If and when lie-detection f.M.R.I.’s are admitted in court, <strong>the</strong>y will raise vexing<br />
questions of self-incrimination and privacy. Hank Greely, a law professor and<br />
head of <strong>the</strong> Stan<strong>for</strong>d Center <strong>for</strong> Law and <strong>the</strong> Biosciences, notes that prosecution<br />
and defense witnesses might have <strong>the</strong>ir credibility questioned if <strong>the</strong>y refused to<br />
take a lie-detection f.M.R.I., as might parties and witnesses in civil cases. Unless<br />
courts found <strong>the</strong> tests to be shocking invasions of privacy, like stomach pumps,<br />
witnesses could even be compelled to have <strong>the</strong>ir brains scanned. And equally<br />
vexing legal questions might arise as neuroimaging technologies move beyond<br />
telling whe<strong>the</strong>r or not someone is lying and begin to identify <strong>the</strong> actual content of<br />
memories. Michael Gazzaniga, a professor of psychology at <strong>the</strong> University of<br />
Cali<strong>for</strong>nia, Santa Barbara, and author of “The Ethical Brain,” notes that within 10<br />
years, neuroscientists may be able to show that <strong>the</strong>re are neurological differences<br />
when people testify about <strong>the</strong>ir own previous acts and when <strong>the</strong>y testify to<br />
something <strong>the</strong>y saw. “If you kill someone, you have a procedural memory of that,<br />
whereas if I’m standing and watch you kill somebody, that’s an episodic memory<br />
that uses a different part of <strong>the</strong> brain,” he told me. Even if witnesses don’t have
<strong>the</strong>ir brains scanned, neuroscience may lead judges and jurors to conclude that<br />
certain kinds of memories are more reliable than o<strong>the</strong>rs because of <strong>the</strong> area of <strong>the</strong><br />
brain in which <strong>the</strong>y are processed. Fur<strong>the</strong>r into <strong>the</strong> future, and closer to science<br />
fiction, lies <strong>the</strong> possibility of memory downloading. “One could even, just barely,<br />
imagine a technology that might be able to ‘read out’ <strong>the</strong> witness’s memories,<br />
intercepted as neuronal firings, and translate it directly into voice, text or <strong>the</strong><br />
equivalent of a movie,” Hank Greely writes.<br />
Greely acknowledges that lie-detection and memory-retrieval technologies like<br />
this could pose a serious challenge to our freedom of thought, which is now<br />
defended largely by <strong>the</strong> First Amendment protections <strong>for</strong> freedom of expression.<br />
“Freedom of thought has always been buttressed by <strong>the</strong> reality that you could<br />
only tell what someone thought based on <strong>the</strong>ir behavior,” he told me. “This<br />
technology holds out <strong>the</strong> possibility of looking through <strong>the</strong> skull and seeing<br />
what’s really happening, seeing <strong>the</strong> thoughts <strong>the</strong>mselves.” According to Greely,<br />
this may challenge <strong>the</strong> principle that we should be held accountable <strong>for</strong> what we<br />
do, not what we think. “It opens up <strong>for</strong> <strong>the</strong> first <strong>time</strong> <strong>the</strong> possibility of punishing<br />
people <strong>for</strong> <strong>the</strong>ir thoughts ra<strong>the</strong>r than <strong>the</strong>ir actions,” he says. “One reason thought<br />
has been free in <strong>the</strong> harshest dictatorships is that dictators haven’t been able to<br />
detect it.” He adds, “Now <strong>the</strong>y may be able to, putting greater pressure on legal<br />
constraints against government interference with freedom of thought.”<br />
In <strong>the</strong> future, neuroscience could also revolutionize <strong>the</strong> way jurors are selected.<br />
Steven Laken, <strong>the</strong> president of Cephos, says that jury consultants might seek to<br />
put prospective jurors in f.M.R.I.’s. “You could give videotapes of <strong>the</strong> lawyers and<br />
witnesses to people when <strong>the</strong>y’re in <strong>the</strong> magnet and see what parts of <strong>the</strong>ir brains<br />
light up,” he says. A situation like this would raise vexing questions about jurors’<br />
prejudices — and what makes <strong>for</strong> a fair trial. Recent experiments have suggested<br />
that people who believe <strong>the</strong>mselves to be free of bias may harbor plenty of it all<br />
<strong>the</strong> same.<br />
The experiments, conducted by Elizabeth Phelps, who teaches psychology at New<br />
York University, combine brain scans with a behavioral test known as <strong>the</strong><br />
Implicit Association Test, or I.A.T., as well as physiological tests of <strong>the</strong> startle<br />
reflex. The I.A.T. flashes pictures of black and white faces at you and asks you to<br />
associate various adjectives with <strong>the</strong> faces. Repeated tests have shown that white
subjects take longer to respond when <strong>the</strong>y’re asked to associate black faces with<br />
positive adjectives and white faces with negative adjectives than vice versa, and<br />
this is said to be an implicit measure of unconscious racism. Phelps and her<br />
colleagues added neurological evidence to this insight by scanning <strong>the</strong> brains and<br />
testing <strong>the</strong> startle reflexes of white undergraduates at Yale be<strong>for</strong>e <strong>the</strong>y took <strong>the</strong><br />
I.A.T. She found that <strong>the</strong> subjects who showed <strong>the</strong> most unconscious bias on <strong>the</strong><br />
I.A.T. also had <strong>the</strong> highest activation in <strong>the</strong>ir amygdalas — a center of threat<br />
perception — when unfamiliar black faces were flashed at <strong>the</strong>m in <strong>the</strong> scanner. By<br />
contrast, when subjects were shown pictures of familiar black and white figures<br />
— like Denzel Washington, Martin Lu<strong>the</strong>r King Jr. and Conan O’Brien — <strong>the</strong>re<br />
was no jump in amygdala activity.<br />
The legal implications of <strong>the</strong> new experiments involving bias and neuroscience<br />
are hotly disputed. Mahzarin R. Banaji, a psychology professor at Harvard who<br />
helped to pioneer <strong>the</strong> I.A.T., has argued that <strong>the</strong>re may be a big gap between <strong>the</strong><br />
concept of intentional bias embedded in law and <strong>the</strong> reality of unconscious<br />
racism revealed by science. When <strong>the</strong> gap is “substantial,” she and <strong>the</strong> U.C.L.A.<br />
law professor Jerry Kang have argued, “<strong>the</strong> law should be changed to comport<br />
with science” — relaxing, <strong>for</strong> example, <strong>the</strong> current focus on intentional<br />
discrimination and trying to root out unconscious bias in <strong>the</strong> workplace with<br />
“structural interventions,” which critics say may be tantamount to racial quotas.<br />
One legal scholar has cited Phelps’s work to argue <strong>for</strong> <strong>the</strong> elimination of<br />
peremptory challenges to prospective jurors — if most whites are unconsciously<br />
racist, <strong>the</strong> argument goes, <strong>the</strong>n any decision to strike a black juror must be<br />
infected with racism. Much to her displeasure, Phelps’s work has been cited by a<br />
journalist to suggest that a white cop who accidentally shot a black teenager on a<br />
Brooklyn rooftop in 2004 must have been responding to a hard-wired fear of<br />
unfamiliar black faces — a version of <strong>the</strong> amygdala made me do it.<br />
Phelps herself says it’s “crazy” to link her work to cops who shoot on <strong>the</strong> job and<br />
insists that it is too early to use her research in <strong>the</strong> courtroom. “Part of my<br />
discom<strong>for</strong>t is that we haven’t linked what we see in <strong>the</strong> amygdala or any o<strong>the</strong>r<br />
region of <strong>the</strong> brain with an activity outside <strong>the</strong> magnet that we would call racism,”<br />
she told me. “We have no evidence whatsoever that activity in <strong>the</strong> brain is more<br />
predictive of things we care about in <strong>the</strong> courtroom than <strong>the</strong> behaviors<br />
<strong>the</strong>mselves that we correlate with brain function.” In o<strong>the</strong>r words, just because
you have a biased reaction to a photograph doesn’t mean you’ll act on those<br />
biases in <strong>the</strong> workplace. Phelps is also concerned that jurors might be unduly<br />
influenced by attention-grabbing pictures of brain scans. “Frank Keil, a<br />
psychologist at Yale, has done research suggesting that when you have a picture<br />
of a mechanism, you have a tendency to overestimate how much you understand<br />
<strong>the</strong> mechanism,” she told me. Defense lawyers confirm this phenomenon. “Here<br />
was this nice color image we could enlarge, that <strong>the</strong> medical expert could point<br />
to,” Christopher Plourd, a San Diego criminal defense lawyer, told The Los<br />
Angeles Times in <strong>the</strong> early 1990s. “It documented that this guy had a rotten spot<br />
in his brain. The jury glommed onto that.”<br />
O<strong>the</strong>r scholars are even sharper critics of ef<strong>for</strong>ts to use scientific experiments<br />
about unconscious bias to trans<strong>for</strong>m <strong>the</strong> law. “I regard that as an extraordinary<br />
claim that you could screen potential jurors or judges <strong>for</strong> bias; it’s mindboggling,”<br />
I was told by Philip Tetlock, professor at <strong>the</strong> Haas School of Business<br />
at <strong>the</strong> University of Cali<strong>for</strong>nia at Berkley. Tetlock has argued that split-second<br />
associations between images of African-Americans and negative adjectives may<br />
reflect “simple awareness of <strong>the</strong> social reality” that “some groups are more<br />
disadvantaged than o<strong>the</strong>rs.” He has also written that, according to psychologists,<br />
“<strong>the</strong>re is virtually no published research showing a systematic link between racist<br />
attitudes, overt or subconscious, and real-world discrimination.” (A few studies<br />
show, Tetlock acknowledges, that openly biased white people some<strong>time</strong>s sit<br />
closer to whites than blacks in experiments that simulate job hiring and<br />
promotion.) “A light bulb going off in your brain means nothing unless it’s<br />
correlated with a particular output, and <strong>the</strong> brain-scan stuff, heaven help us, we<br />
have barely linked that with anything,” agrees Tetlock’s co-author, Amy Wax of<br />
<strong>the</strong> University of Pennsylvania Law School. “The claim that homeless people light<br />
up your amygdala more and your frontal cortex less and we can infer that you will<br />
systematically dehumanize homeless people — that’s piffle.”<br />
V. Are You Responsible <strong>for</strong> What You Might Do The attempt to link unconscious<br />
bias to actual acts of discrimination may be dubious. But are <strong>the</strong>re o<strong>the</strong>r ways to<br />
look inside <strong>the</strong> brain and make predictions about an individual’s future behavior<br />
And if so, should those discoveries be employed to make us safer Ef<strong>for</strong>ts to use<br />
science to predict criminal behavior have a disreputable history. In <strong>the</strong> 19th<br />
century, <strong>the</strong> Italian criminologist Cesare Lombroso championed a <strong>the</strong>ory of
“biological criminality,” which held that criminals could be identified by physical<br />
characteristics, like large jaws or bushy eyebrows. Never<strong>the</strong>less, neuroscientists<br />
are trying to find <strong>the</strong> factors in <strong>the</strong> brain associated with violence. PET scans of<br />
convicted murderers were first studied in <strong>the</strong> late 1980s by Adrian Raine, a<br />
professor of psychology at <strong>the</strong> University of Sou<strong>the</strong>rn Cali<strong>for</strong>nia; he found that<br />
<strong>the</strong>ir prefrontal cortexes, areas associated with inhibition, had reduced glucose<br />
metabolism and suggested that this might be responsible <strong>for</strong> <strong>the</strong>ir violent<br />
behavior. In a later study, Raine found that subjects who received a diagnosis of<br />
antisocial personality disorder, which correlates with violent behavior, had 11<br />
percent less gray matter in <strong>the</strong>ir prefrontal cortexes than control groups of<br />
healthy subjects and substance abusers. His current research uses f.M.R.I.’s to<br />
study moral decision-making in psychopaths.<br />
Neuroscience, it seems, points two ways: it can absolve individuals of<br />
responsibility <strong>for</strong> acts <strong>the</strong>y’ve committed, but it can also place individuals in<br />
jeopardy <strong>for</strong> acts <strong>the</strong>y haven’t committed — but might someday. “This opens up a<br />
Pandora’s box in civilized society that I’m willing to fight against,” says Helen S.<br />
Mayberg, a professor of psychiatry, behavioral sciences and neurology at Emory<br />
University School of Medicine, who has testified against <strong>the</strong> admission of<br />
neuroscience evidence in criminal trials. “If you believe at <strong>the</strong> <strong>time</strong> of trial that<br />
<strong>the</strong> picture in<strong>for</strong>ms us about what <strong>the</strong>y were like at <strong>the</strong> <strong>time</strong> of <strong>the</strong> crime, <strong>the</strong>n <strong>the</strong><br />
picture moves <strong>for</strong>ward. You need to be prepared <strong>for</strong>: ‘This spot is a sign of future<br />
dangerousness,’ when someone is up <strong>for</strong> parole. They have a scan, <strong>the</strong> spot is<br />
<strong>the</strong>re, so <strong>the</strong>y don’t get out. It’s carved in your brain.”<br />
O<strong>the</strong>r scholars see little wrong with using brain scans to predict violent<br />
tendencies and sexual predilections — as long as <strong>the</strong> scans are used within limits.<br />
“It’s not necessarily <strong>the</strong> case that if predictions work, you would say take that guy<br />
off <strong>the</strong> street and throw away <strong>the</strong> key,” says Hank Greely, <strong>the</strong> Stan<strong>for</strong>d law<br />
professor. “You could require counseling, surveillance, G.P.S. transmitters or<br />
warning <strong>the</strong> neighbors. None of <strong>the</strong>se are necessarily benign, but <strong>the</strong>y beat <strong>the</strong><br />
heck out of preventative detention.” Greely has little doubt that predictive<br />
technologies will be enlisted in <strong>the</strong> war on terror — perhaps in radical ways.<br />
“Even with today’s knowledge, I think we can tell whe<strong>the</strong>r someone has a strong<br />
emotional reaction to seeing things, and I can certainly imagine a friend-versusfoe<br />
scanner. If you put everyone who reacts badly to an American flag in a
concentration camp or Guantánamo, that would be bad, but in an occupation<br />
situation, to mark someone down <strong>for</strong> fur<strong>the</strong>r surveillance, that might be<br />
appropriate.”<br />
Paul Root Wolpe, who teaches social psychiatry and psychiatric ethics at <strong>the</strong><br />
University of Pennsylvania School of Medicine, says he anticipates that<br />
neuroscience predictions will move beyond <strong>the</strong> courtroom and will be used to<br />
make predictions about citizens in all walks of life.<br />
“Will we use brain imaging to track kids in school because we’ve discovered that<br />
certain brain function or morphology suggests aptitude” he asks. “I work <strong>for</strong><br />
NASA, and imagine how helpful it might be <strong>for</strong> NASA if it could scan your brain<br />
to discover whe<strong>the</strong>r you have a good enough spatial sense to be a pilot.” Wolpe<br />
says that brain imaging might eventually be used to decide if someone is a worthy<br />
foster or adoptive parent — a history of major depression and cocaine abuse can<br />
leave telltale signs on <strong>the</strong> brain, <strong>for</strong> example, and future studies might find parts<br />
of <strong>the</strong> brain that correspond to nurturing and caring.<br />
The idea of holding people accountable <strong>for</strong> <strong>the</strong>ir predispositions ra<strong>the</strong>r than <strong>the</strong>ir<br />
actions poses a challenge to one of <strong>the</strong> central principles of Anglo-American<br />
jurisprudence: namely, that people are responsible <strong>for</strong> <strong>the</strong>ir behavior, not <strong>the</strong>ir<br />
proclivities — <strong>for</strong> what <strong>the</strong>y do, not what <strong>the</strong>y think. “We’re going to have to make<br />
a decision about <strong>the</strong> skull as a privacy domain,” Wolpe says. Indeed, Wolpe<br />
serves on <strong>the</strong> board of an organization called <strong>the</strong> Center <strong>for</strong> Cognitive Liberty and<br />
Ethics, a group of neuroscientists, legal scholars and privacy advocates<br />
“dedicated to protecting and advancing freedom of thought in <strong>the</strong> modern world<br />
of accelerating neurotechnologies.”<br />
There may be similar “cognitive liberty” battles over ef<strong>for</strong>ts to repair or enhance<br />
broken brains. A remarkable technique called transcranial magnetic stimulation,<br />
<strong>for</strong> example, has been used to stimulate or inhibit specific regions of <strong>the</strong> brain. It<br />
can temporarily alter how we think and feel. Using T.M.S., Ernst Fehr and Daria<br />
Knoch of <strong>the</strong> University of Zurich temporarily disrupted each side of <strong>the</strong><br />
dorsolateral prefrontal cortex in test subjects. They asked <strong>the</strong>ir subjects to<br />
participate in an experiment that economists call <strong>the</strong> ultimatum game. One<br />
person is given $20 and told to divide it with a partner. If <strong>the</strong> partner rejects <strong>the</strong>
proposed amount as too low, nei<strong>the</strong>r person gets any money. Subjects whose<br />
prefrontal cortexes were functioning properly tended to reject offers of $4 or less:<br />
<strong>the</strong>y would ra<strong>the</strong>r get no money than accept an offer that struck <strong>the</strong>m as insulting<br />
and unfair. But subjects whose right prefrontal cortexes were suppressed by<br />
T.M.S. tended to accept <strong>the</strong> $4 offer. Although <strong>the</strong> offer still struck <strong>the</strong>m as<br />
insulting, <strong>the</strong>y were able to suppress <strong>the</strong>ir indignation and to pursue <strong>the</strong> selfishly<br />
rational conclusion that a low offer is better than nothing.<br />
Some neuroscientists believe that T.M.S. may be used in <strong>the</strong> future to en<strong>for</strong>ce a<br />
vision of <strong>the</strong>rapeutic justice, based on <strong>the</strong> idea that defective brains can be cured.<br />
“Maybe somewhere down <strong>the</strong> line, a badly damaged brain would be viewed as<br />
something that can heal, like a broken leg that needs to be repaired,” <strong>the</strong><br />
neurobiologist Robert Sapolsky says, although he acknowledges that defining<br />
what counts as a normal brain is politically and scientifically fraught. Indeed,<br />
ef<strong>for</strong>ts to identify normal and abnormal brains have been responsible <strong>for</strong> some of<br />
<strong>the</strong> darkest movements in <strong>the</strong> history of science and technology, from phrenology<br />
to eugenics. “How far are we willing to go to use neurotechnology to change<br />
people’s brains we consider disordered” Wolpe asks. “We might find a part of<br />
<strong>the</strong> brain that seems to be malfunctioning, like a discrete part of <strong>the</strong> brain<br />
operative in violent or sexually predatory behavior, and <strong>the</strong>n turn off or inhibit<br />
that behavior using transcranial magnetic stimulation.” Even behaviors in <strong>the</strong><br />
normal range might be fine-tuned by T.M.S.: jurors, <strong>for</strong> example, could be made<br />
more emotional or more deliberative with magnetic interventions. Mark George,<br />
an adviser to <strong>the</strong> Cephos company and also director of <strong>the</strong> Medical University of<br />
South Carolina Center <strong>for</strong> Advanced Imaging Research, has submitted a patent<br />
application <strong>for</strong> a T.M.S. procedure that supposedly suppresses <strong>the</strong> area of <strong>the</strong><br />
brain involved in lying and makes a person less capable of not telling <strong>the</strong> truth.<br />
As <strong>the</strong> new technologies proliferate, even <strong>the</strong> neurolaw experts <strong>the</strong>mselves have<br />
only begun to think about <strong>the</strong> questions that lie ahead. Can <strong>the</strong> police get a search<br />
warrant <strong>for</strong> someone’s brain Should <strong>the</strong> Fourth Amendment protect our minds<br />
in <strong>the</strong> same way that it protects our houses Can courts order tests of suspects’<br />
memories to determine whe<strong>the</strong>r <strong>the</strong>y are gang members or police in<strong>for</strong>mers, or<br />
would this violate <strong>the</strong> Fifth Amendment’s ban on compulsory self-incrimination<br />
Would punishing people <strong>for</strong> <strong>the</strong>ir thoughts ra<strong>the</strong>r than <strong>for</strong> <strong>the</strong>ir actions violate<br />
<strong>the</strong> Eighth Amendment’s ban on cruel and unusual punishment However
astonishing our machines may become, <strong>the</strong>y cannot tell us how to answer <strong>the</strong>se<br />
perplexing questions. We must instead look to our own powers of reasoning and<br />
intuition, relatively primitive as <strong>the</strong>y may be. As Stephen Morse puts it,<br />
neuroscience itself can never identify <strong>the</strong> mysterious point at which people<br />
should be excused from responsibility <strong>for</strong> <strong>the</strong>ir actions because <strong>the</strong>y are not able,<br />
in some sense, to control <strong>the</strong>mselves. That question, he suggests, is “moral and<br />
ultimately legal,” and it must be answered not in laboratories but in courtrooms<br />
and legislatures. In o<strong>the</strong>r words, we must answer it ourselves.<br />
Jeffrey Rosen, a frequent contributor, is <strong>the</strong> author most recently of “The<br />
Supreme Court: The Personalities and Rivalries That Defined America.”
Brain science offers insight to teen crime : Special Reports : Albuquerque Tribune<br />
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Brain science offers insight to teen crime<br />
By Joline Gutierrez Krueger (Contact)<br />
Friday, December 8, 2006<br />
Should Michael Brown have<br />
been given such a harsh <strong>adult</strong><br />
sentence <strong>for</strong> his role in <strong>the</strong><br />
deaths of his grandparents<br />
Yes<br />
No<br />
See <strong>the</strong> results without voting ».<br />
Smart Box<br />
Thinking like a teen<br />
Scientists and members of <strong>the</strong><br />
juvenile justice system are giving<br />
greater thought to whe<strong>the</strong>r<br />
differences between <strong>the</strong> brain of an<br />
adolescent and that of an <strong>adult</strong><br />
should have different implications<br />
<strong>for</strong> each in <strong>the</strong> criminal justice<br />
system.<br />
Amygdala: The brain's emotional<br />
center, which controls anger, fear,<br />
recklessness, among o<strong>the</strong>r<br />
reactions. In teens, <strong>the</strong> activity<br />
here is in high gear. In <strong>adult</strong>s, it's<br />
tempered by a more developed<br />
frontal lobe.<br />
Frontal lobe: The brain's executive<br />
center, which includes <strong>the</strong><br />
prefrontal cortex, responsible <strong>for</strong><br />
anticipating consequences,<br />
http://www.abqtrib.com/news/2006/dec/08/brain-science-offers-insight-teen-crime/ (1 of 6)12/15/2006 2:32:28 PM<br />
What was<br />
Michael Brown<br />
thinking<br />
Jurors pondered<br />
that nearly 12<br />
years ago be<strong>for</strong>e<br />
deciding on <strong>the</strong><br />
guilty verdict that<br />
would lock <strong>the</strong><br />
teen away <strong>for</strong><br />
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Brain science offers insight to teen crime : Special Reports : Albuquerque Tribune<br />
planning and controlling impulses.<br />
In short, it keeps <strong>the</strong> amygdala in<br />
check. In teens, however, this area<br />
is barely functioning and will not be<br />
fully developed until age 20 to 25.<br />
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market<br />
7. PBS `Detectives' visits museum <strong>for</strong> typewriter clues<br />
8. Saudis would back Sunnis<br />
9. Unsers' lawyers call deputies "substandard"<br />
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decades in an<br />
<strong>adult</strong> prison.<br />
They questioned<br />
why a 16-yearold<br />
boy with no previous history of violence did nothing to stop his teen pals from stabbing his screaming<br />
grandparents in 1994 unless he was <strong>the</strong> cold and calculating killer prosecutors said he was.<br />
But if <strong>the</strong> trial took place now or years from now, would science have played a greater role in <strong>the</strong>ir deliberating<br />
Would Brown have been saved from <strong>the</strong> <strong>adult</strong> sanctions because of his teenage brain<br />
Advances in brain research suggest it's possible.<br />
Scientists are now seeing beyond <strong>the</strong> skull into an emerging debate over whe<strong>the</strong>r <strong>the</strong> differences between <strong>the</strong><br />
brain of an adolescent and an <strong>adult</strong> should have different implications <strong>for</strong> each in <strong>the</strong> criminal justice system.<br />
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Studies being conducted at institutions such as <strong>the</strong> Laboratory <strong>for</strong> Adolescent Science at Dartmouth College and<br />
<strong>the</strong> National Institute of Mental Health in Be<strong>the</strong>sda, Md., could someday lead to <strong>the</strong> development of tools to aid in<br />
determining juvenile offenders' degree of culpability as compared with <strong>adult</strong>s.<br />
That could mean future Michael Browns will have an additional argument <strong>for</strong> receiving juvenile sanctions, not<br />
<strong>adult</strong> sentences, in cases of kids who kill.<br />
"We are interested in <strong>the</strong> broader question of whe<strong>the</strong>r juveniles should be punished to <strong>the</strong> same extent as <strong>adult</strong>s<br />
who have committed comparable crimes," said psychologist Laurence Steinberg in his 2003 article, "Less Guilty<br />
by Reason of Adolescence."<br />
Take a "CSI" look into <strong>the</strong> teenage brain and you'll notice a firestorm of activity. But experts say it's where that<br />
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Brain science offers insight to teen crime : Special Reports : Albuquerque Tribune<br />
activity is taking place - and where it isn't - that makes <strong>the</strong> crucial difference.<br />
The gray matter chatter in a teen brain is in full swing deep within <strong>the</strong> temporal lobe in an almond-shaped bulge<br />
called <strong>the</strong> amygdala, <strong>the</strong> brain's emotional center.<br />
In <strong>adult</strong>s, <strong>the</strong> amygdala's emotional and often impulsive or erratic reactions such as anger, fear and recklessness<br />
are tempered by <strong>the</strong> reasoning and social awareness of <strong>the</strong> brain's frontal lobe.<br />
Cerebral construction is not complete until around ages 20 to 25, most scientists agree. The frontal lobe is one of<br />
<strong>the</strong> last areas of <strong>the</strong> brain to develop.<br />
In <strong>the</strong> adolescent brain, it's barely firing at all.<br />
Without <strong>the</strong> frontal lobe on board, it becomes physiologically harder <strong>for</strong> a teen to completely understand <strong>the</strong><br />
future consequences of his or her emotional or impulsive actions, scientists contend.<br />
"Thus, <strong>the</strong>re is good reason to believe that adolescents, as compared with <strong>adult</strong>s, are more susceptible to<br />
influence, less future-oriented, less risk averse and less able to manage <strong>the</strong>ir impulses and behavior," Steinberg<br />
said.<br />
He and o<strong>the</strong>rs advocate that such a discrepancy in brain function should be taken into consideration when<br />
deciding to seek juvenile or <strong>adult</strong> sanctions.<br />
Childhood abuse and neglect fur<strong>the</strong>r hampers normal brain development, researchers say. A recent study by <strong>the</strong><br />
Juvenile Justice Center of <strong>the</strong> American Bar Association found that a majority of juveniles on death rows across<br />
<strong>the</strong> country had been abused or neglected as children.<br />
A U.S. Supreme Court decision last year now prohibits sentencing a juvenile to death, a decision that took into<br />
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Brain science offers insight to teen crime : Special Reports : Albuquerque Tribune<br />
consideration <strong>the</strong> incomplete brain development in juveniles. Court observers say that decision could have<br />
striking implications in cases where <strong>adult</strong> sanctions are being sought <strong>for</strong> juvenile offenders.<br />
No one is saying, however, that an immature brain is an excuse <strong>for</strong> committing crime - nor does it exonerate a<br />
juvenile from <strong>the</strong> consequences of breaking <strong>the</strong> law.<br />
It "does not excuse violent criminal behavior, but it's an important factor <strong>for</strong> courts to consider," according to a<br />
statement from <strong>the</strong> American Psychiatric Association.<br />
Chief Bernalillo County Deputy District Attorney Todd Heisey warns that brain science cannot predict which teen<br />
can be rehabilitated and which is a budding psychopath.<br />
"I think it's too soon to simply rely on that sort of technology," he said. "Some kids are just violent; some kids can<br />
get better once <strong>the</strong>y face <strong>the</strong>ir consequences. The trick is to know which is which."<br />
Presiding Children's Court Judge Marie Baca said she is beginning to see more discussion of <strong>the</strong> juvenile brain in<br />
her Albuquerque courtroom.<br />
"It's a controversial area," said Baca. "It's hard to go from this tough-love position where we hold juveniles<br />
accountable <strong>for</strong> <strong>the</strong>ir actions, including murder. But it's important, I think, to realize that children don't behave like<br />
little <strong>adult</strong>s."<br />
State District Judge Louis McDonald, who sentenced Brown and his two teen co-defendants as <strong>adult</strong>s, said <strong>the</strong><br />
brain-science debate has yet to enter his courtroom, located in Bernalillo.<br />
Still, he said he tries to keep up with current research on <strong>the</strong> issue.<br />
"The difficult thing about sentencing kids is everything I've seen about teenagers is that <strong>the</strong>ir brains are not<br />
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Brain science offers insight to teen crime : Special Reports : Albuquerque Tribune<br />
complete," he said. "There is so much going on in <strong>the</strong>re. They act impulsively. Some<strong>time</strong>s <strong>the</strong>y do things <strong>the</strong>y've<br />
never even reflected on."<br />
McDonald said he doubts Brown and <strong>the</strong> o<strong>the</strong>r two, Bernadette Setser and Jeremy Rose, know to this day why<br />
<strong>the</strong>y did what <strong>the</strong>y did on a February night nearly 13 years ago when <strong>the</strong>y took two lives and tossed away <strong>the</strong>ir<br />
own.<br />
"They don't understand what <strong>the</strong>y were thinking," he said.<br />
Brain research suggests that <strong>the</strong> question <strong>the</strong>y should be asking is not what <strong>the</strong>y were thinking but how <strong>the</strong>y<br />
were thinking.<br />
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http://www.abqtrib.com/news/2006/dec/08/brain-science-offers-insight-teen-crime/ (5 of 6)12/15/2006 2:32:28 PM
Brain Maturation and <strong>the</strong> Execution of Juveniles<br />
Some reflections on science and <strong>the</strong> law.<br />
Illustration ©David Hollenbach<br />
issue.<br />
By Ruben C. Gur | By Ruben C. Gur | Should <strong>the</strong> death penalty be applied to<br />
offenders who were “juvenile” but over <strong>the</strong> age of 16 when <strong>the</strong>y committed<br />
<strong>the</strong>ir crimes As I am writing, <strong>the</strong> U.S. Supreme Court is deliberating this<br />
The attorneys arguing against juvenile execution used evidence from research on brain<br />
development to claim that <strong>the</strong> juvenile brain is insufficiently mature in areas relevant to<br />
criminal culpability to warrant <strong>the</strong> ultimate punishment. This is how I was dragged out<br />
of my hiding in <strong>the</strong> laboratory and into <strong>the</strong> midst of legal deliberations, culminating in<br />
amicus briefs and conferences with glitzy legal teams.<br />
The first hint of <strong>the</strong> storm came two years ago, with a call from a lawyer, Marc Bookman<br />
C’78, from <strong>the</strong> Defender Association of Philadelphia. He asked if I knew of or could<br />
prepare a review of <strong>the</strong> literature on brain development; he needed one to help a
Pennsylvania man who was facing <strong>the</strong> death penalty <strong>for</strong> crimes committed as a juvenile.<br />
I happened to have reviewed this literature <strong>for</strong> a manuscript reporting our own data<br />
from longitudinal studies per<strong>for</strong>med by Penn’s Brain Behavior Laboratory and <strong>the</strong><br />
Schizophrenia Center, and so I agreed to augment it and make it more readable <strong>for</strong> nonexperts.<br />
He sent it back to me, this <strong>time</strong> <strong>for</strong>matted as an affidavit in <strong>the</strong> case of a Mr.<br />
Hector Huertas. He asked whe<strong>the</strong>r I would mind reviewing <strong>the</strong> affidavit and, if I agreed<br />
with its contents, to notarize and sign it. Well, I agreed and it apparently worked. The<br />
Commonwealth decided not to pursue <strong>the</strong> death penalty in light of scientific findings<br />
that <strong>the</strong> brain does not mature until early <strong>adult</strong>hood. Soon afterward Mr. Bookman<br />
called again, this <strong>time</strong> to help a colleague in Texas who was defending a Mr. Toronto<br />
Patterson, a death-row inmate who also committed his crime when he was an<br />
adolescent.<br />
The affidavit did not save Mr. Patterson’s life, but while <strong>the</strong> U.S. Supreme Court refused<br />
to hear <strong>the</strong> appeal, it expressed interest in <strong>the</strong> scientific evidence from brain research<br />
that was presented in <strong>the</strong> case, and invited such arguments in future cases. The race was<br />
on to see what would be <strong>the</strong> test case determining whe<strong>the</strong>r <strong>the</strong> death penalty will apply<br />
to juvenile defendants, and I found myself being asked to sign affidavits from around<br />
<strong>the</strong> country. The “winner” was a Missouri man, Mr. Christopher Simmons (Roper v.<br />
Simmons). Below is a summary of <strong>the</strong> material I have submitted as part of an amicus<br />
organized by Mr. Simmons’ defense:<br />
The rate at which <strong>the</strong> human brain matures has been of considerable interest to<br />
neuroscientists, and knowledge of when different brain regions mature in human<br />
development may have profound implications <strong>for</strong> understanding behavioral<br />
development. Although <strong>the</strong> brain and its structure become well differentiated during<br />
fetal development, <strong>the</strong>re is overwhelming evidence that much of <strong>the</strong> maturational<br />
process occurs after birth. Indeed, projections from early pioneering work on donated<br />
brain tissue have indicated that some brain regions do not reach maturity in humans<br />
until <strong>adult</strong>hood. These projections have been confirmed by more recent neuroimaging<br />
studies.<br />
While sophisticated methods <strong>for</strong> preservation and dissection of postmortem brain tissue<br />
had been developed in <strong>the</strong> first decades of <strong>the</strong> 20th century, it was not until <strong>the</strong> 1960s<br />
that enough such tissue was available to examine <strong>the</strong> question of brain maturation in<br />
humans. Arguably <strong>the</strong> largest collection and <strong>the</strong> most influential work was that of Dr.<br />
Paul I. Yakovlev and his colleagues at Harvard University. His work has focused on <strong>the</strong><br />
creation of myelin, fatty tissue surrounding nerve fibers. This process, known as<br />
myelogenesis, is important <strong>for</strong> assuring efficient transmission of neuronal signals;<br />
myelin surrounds <strong>the</strong> nerve fibers that carry in<strong>for</strong>mation across large distances very<br />
much in <strong>the</strong> same way that rubber is used <strong>for</strong> insulating cables designed to conduct<br />
electricity across distance.<br />
Yakovlev examined slices of brain tissue from a wide age range of more than 200 brains,<br />
finding that especially late to myelinate were those parts of <strong>the</strong> brain that inhibit and<br />
modulate <strong>the</strong> more primitive, drive-related activation of <strong>the</strong> limbic areas. As interpreted<br />
by Yakovlev and his colleagues, <strong>the</strong> anatomic data indicated that <strong>the</strong> very functions that
make us uniquely human are <strong>the</strong> latest to become fully integrated into <strong>the</strong> workings of<br />
<strong>the</strong> developing brain.<br />
University of Chicago researcher Peter Huttenlocher uncovered ano<strong>the</strong>r<br />
neurodevelopmental phenomenon apparently taking place during adolescence:<br />
pruning. According to <strong>the</strong> pruning hypo<strong>the</strong>sis, neurons and <strong>the</strong>ir connections that have<br />
not been consistently used during childhood “shrivel off” and are eliminated at some<br />
point during adolescence, <strong>the</strong>reby allowing <strong>for</strong> greater efficiency of <strong>the</strong> remaining neural<br />
systems.<br />
Postmortem tissue studies have contributed important insights into understanding<br />
brain maturation, but <strong>the</strong>y have serious limitations, including tissue availability and <strong>the</strong><br />
inability to trace developmental changes in <strong>the</strong> same individual.<br />
These difficulties are circumvented by a set of novel techniques—developed in <strong>the</strong> 1970s<br />
and fully implemented by <strong>the</strong> 1990s—that can be generally referred to as structural<br />
imaging. These methods permit visualization and volumetric measurement of brain<br />
structure in living people without any risk to <strong>the</strong> subjects. The method that has become<br />
state-of-<strong>the</strong>-art <strong>for</strong> <strong>the</strong>se studies is based on magnetic resonance imaging (MRI)<br />
procedures. MRI has provided data on <strong>the</strong> composition of three brain components, or<br />
compartments: gray matter—nerve tissue responsible <strong>for</strong> in<strong>for</strong>mation processing; white<br />
matter—nerve tissue responsible <strong>for</strong> in<strong>for</strong>mation transmission; and cerebrospinal fluid.<br />
This division of <strong>the</strong> brain into <strong>the</strong>se compartments is termed segmentation.<br />
In one of <strong>the</strong> first studies examining segmented MRI in children and <strong>adult</strong>s, researchers<br />
Terry Jernigan and Paula Tallal from <strong>the</strong> University of Cali<strong>for</strong>nia have documented <strong>the</strong><br />
pruning process. They found that children had higher volumes of gray matter than<br />
<strong>adult</strong>s, indicating loss of gray matter during adolescence. In ano<strong>the</strong>r study Stan<strong>for</strong>d<br />
researchers Adolph Pfefferbaum and Calvin Lim demonstrated a clearly different<br />
developmental course <strong>for</strong> gray matter and white matter: The <strong>for</strong>mer declined steadily<br />
during adolescence while <strong>the</strong> latter increased in volume until about 20-22 years of age.<br />
A subsequent NIH study led by Judith Rappoport pinpointed <strong>the</strong> greatest delay in<br />
myelination <strong>for</strong> <strong>the</strong> brain’s fronto-temporal pathways.<br />
In <strong>the</strong> only study to date that examined segmented MRI volumes from a prospective<br />
sample of 28 healthy children aged one month to 10 years, as well as a small <strong>adult</strong><br />
sample, researchers from Penn and Toyama University in Japan applied segmentation<br />
procedures developed by <strong>the</strong> Penn group. This, actually, was <strong>the</strong> very study that<br />
prompted me to write a review of <strong>the</strong> literature, which I used <strong>for</strong> Mr. Bookman’s<br />
request. We found that while gray matter volume peaked at about two years of age, <strong>the</strong><br />
volume of white matter, which indicates brain maturation, continued to increase into<br />
<strong>adult</strong>hood. Fur<strong>the</strong>rmore, we found that <strong>the</strong> frontal lobe showed <strong>the</strong> greatest<br />
maturational lag and its myelination is unlikely to be completed be<strong>for</strong>e young<br />
<strong>adult</strong>hood.<br />
Most recently, investigators at UCLA’s brain imaging center analyzed MRI scans of 13<br />
healthy children over a period of eight to 10 years. They concluded that brain areas in
<strong>the</strong> cerebral cortex, responsible <strong>for</strong> higher-order integration, mature only after lowerorder<br />
somatosensory and visual cortices are developed.<br />
My review of <strong>the</strong> data found overwhelming evidence indicating that <strong>the</strong> main index of<br />
maturation, which is <strong>the</strong> process called myelination, is not complete until some <strong>time</strong> in<br />
<strong>the</strong> beginning of <strong>the</strong> third decade of life (probably at around ages 20-22). O<strong>the</strong>r<br />
maturational processes, such as <strong>the</strong> increase and subsequent elimination (“pruning”) in<br />
cell number and connectivity, may be completed by late adolescence, perhaps by ages<br />
15-17. (More data are needed to know <strong>for</strong> sure.) These results have ra<strong>the</strong>r profound<br />
implications <strong>for</strong> understanding behavioral development. The cortical regions that are<br />
last to mature, particularly those in prefrontal areas, are involved in behavioral facets<br />
germane to many aspects of criminal culpability. Perhaps most relevant is <strong>the</strong><br />
involvement of <strong>the</strong>se brain regions in <strong>the</strong> control of aggression and o<strong>the</strong>r impulses, <strong>the</strong><br />
process of planning <strong>for</strong> long-range goals, organization of sequential behavior, <strong>the</strong><br />
process of abstraction and mental flexibility, and aspects of memory including “working<br />
memory.” If <strong>the</strong> neural substrates of <strong>the</strong>se behaviors have not reached maturity be<strong>for</strong>e<br />
<strong>adult</strong>hood, it is unreasonable to expect <strong>the</strong> behaviors <strong>the</strong>mselves to reflect mature<br />
thought processes.<br />
As I stated in my expert opinion <strong>for</strong> <strong>the</strong> court, <strong>the</strong> brain-scan techniques have<br />
demonstrated conclusively that <strong>the</strong> phenomena observed by mental-health<br />
professionals in persons under 18, which would render <strong>the</strong>m less morally blameworthy<br />
<strong>for</strong> offenses, have a scientific grounding in neural substrates.<br />
The evidence now is strong that <strong>the</strong> brain does not cease to mature until <strong>the</strong> early 20s in<br />
those relevant parts that govern impulsivity, judgment, planning <strong>for</strong> <strong>the</strong> future, <strong>for</strong>esight<br />
of consequences, and o<strong>the</strong>r characteristics that make people morally culpable.<br />
There<strong>for</strong>e, from <strong>the</strong> perspective of neural development, someone under 20 should be<br />
considered to have an underdeveloped brain. Additionally, since brain development in<br />
<strong>the</strong> relevant areas goes in phases that vary in rate and is usually not complete be<strong>for</strong>e <strong>the</strong><br />
early to mid-20s, <strong>the</strong>re is no way to state with any scientific reliability that an individual<br />
17-year-old has a fully matured brain (and should be eligible <strong>for</strong> <strong>the</strong> most severe<br />
punishment), no matter how many o<strong>the</strong>rwise accurate tests and measures might be<br />
applied to him at <strong>the</strong> <strong>time</strong> of his trial <strong>for</strong> capital murder. This is similar to o<strong>the</strong>r physical<br />
characteristics such as height. While we know <strong>the</strong> age at which <strong>the</strong> average <strong>adult</strong> reaches<br />
his or her maximal height, predictions <strong>for</strong> individuals are not easy to make. Thus,<br />
although 18 is an arbitrary cutoff, given <strong>the</strong> ongoing development of <strong>the</strong> brain in most<br />
individuals, it must be preferred over 17 to assure that only <strong>the</strong> most culpable are<br />
punished <strong>for</strong> capital crimes. Indeed, age 21 or 22 would be closer to <strong>the</strong> “biological” age<br />
of maturity.<br />
Dr. Ruben Gur is a professor of psychology in <strong>the</strong> Department of Psychiatry (with secondary appointments in Radiology<br />
and Neurology) and director of <strong>the</strong> Brain Behavior Laboratory in <strong>the</strong> School of Medicine.<br />
©2005 The Pennsylvania Gazette<br />
Last modified 01/05/05
New research shows stark differences in teen brains<br />
New research shows stark differences in teen<br />
brains<br />
Lee Bowman, Scripps Howard<br />
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Written by: Lee Bowman, Scripps Howard<br />
May 11, 2004:<br />
Scripps Howard News Service<br />
New research shows stark differences in teen brains<br />
By Lee Bowman<br />
Recent popular films depicting teenagers suddenly housed in <strong>adult</strong> bodies have more<br />
than a little truth in <strong>the</strong>m.<br />
The latest brain research has found strong evidence that when it comes to maturity,<br />
organization and control, key parts of <strong>the</strong> brain related to emotions, judgment and<br />
"thinking ahead" are <strong>the</strong> last to arrive.<br />
"It seems that regulation of impulse control is <strong>the</strong> last on board and often <strong>the</strong> first to<br />
leave in <strong>the</strong> brain as we age," said Dr. Ruben Gur, a professor of psychology and<br />
director of <strong>the</strong> Brain Behavior Laboratory at <strong>the</strong> University of Pennsylvania who has<br />
been researching brain development in young <strong>adult</strong>s.<br />
Until recently, most brain experts thought <strong>the</strong> human command center stopped<br />
growing at around 18 months, and that neurons were pretty much set <strong>for</strong> life by age<br />
3.<br />
In fact, <strong>the</strong> brain's gray matter has a final growth spurt around <strong>the</strong> ages of 11 to 13<br />
in <strong>the</strong> frontal lobes of <strong>the</strong> brain, <strong>the</strong> regions that guide human intellect and planning.<br />
But it seems to take most of <strong>the</strong> teen years <strong>for</strong> youngsters to link <strong>the</strong>se new cells to<br />
<strong>the</strong> rest of <strong>the</strong>ir brains and solidify <strong>the</strong> millions of connections that allow <strong>the</strong>m to<br />
think and behave like <strong>adult</strong>s.<br />
At <strong>the</strong> same <strong>time</strong>, <strong>the</strong> release of a cascade of adolescent hormones during and after<br />
puberty causes o<strong>the</strong>r areas of <strong>the</strong> brain, particularly <strong>the</strong> amygdala, which governs<br />
basic emotional response, to fire up or expand.<br />
The result is that teens look at things differently than <strong>adult</strong>s. This has tremendous<br />
implications <strong>for</strong> education, mental health, drug abuse and moral and legal<br />
responsibility of adolescents.<br />
Deborah Yurgelun-Todd of Harvard Medical School and McClean Hospital in Boston<br />
has studied how teenagers and <strong>adult</strong>s respond differently to <strong>the</strong> same images.<br />
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New research shows stark differences in teen brains<br />
Shown a set of photos of people's faces contorted in fear, <strong>adult</strong>s named <strong>the</strong> right<br />
emotion, but teens seldom did, often saying <strong>the</strong> person was angry.<br />
When Yurgelun-Todd and her team did <strong>the</strong> same test while doing functional<br />
magnetic resonance imaging of <strong>the</strong> subject's brains, <strong>the</strong>y found a stark difference in<br />
<strong>the</strong> parts being used. Adults used both <strong>the</strong> advanced prefrontal cortex and <strong>the</strong> more<br />
basic amygdala to evaluate what <strong>the</strong>y had seen; younger teens relied entirely on <strong>the</strong><br />
amygdala, while older teens (top age in <strong>the</strong> group was 17) showed a progressive<br />
shift toward using <strong>the</strong> frontal area of <strong>the</strong> brain.<br />
"Just because teens are physically mature, <strong>the</strong>y may not appreciate <strong>the</strong><br />
consequences or weigh in<strong>for</strong>mation <strong>the</strong> same way as <strong>adult</strong>s do," Yurgelun-Todd said.<br />
"Good judgment is learned, but you can't learn it if you don't have <strong>the</strong> necessary<br />
hardware."<br />
There is more evidence of <strong>the</strong> differences:<br />
●<br />
A recent imaging study by researchers at <strong>the</strong> National Institute on Alcohol<br />
Abuse and Alcoholism found that teens taking an experimental gambling test<br />
are less likely to activate a region in <strong>the</strong> base of <strong>the</strong> brain that motivates<br />
behavior to work to obtain rewards than a control group of young <strong>adult</strong>s, ages<br />
22-28, playing <strong>the</strong> same games.<br />
●<br />
Numerous studies show alcohol and perhaps o<strong>the</strong>r drugs hit teen brains harder<br />
than <strong>the</strong>y do <strong>adult</strong> brains. The frontal lobes and <strong>the</strong> hippocampus, which is<br />
involved in memory <strong>for</strong>mation, are particularly vulnerable.<br />
●<br />
It has been known <strong>for</strong> some <strong>time</strong> that children have sharp growth spurts in<br />
brain connections among regions specialized <strong>for</strong> language and spatial<br />
relationships between ages 6 and 12. That language capacity tends to reside<br />
mostly in a person's nondominant side - <strong>the</strong> left hemisphere of <strong>the</strong> brain in<br />
right-handers, <strong>for</strong> instance. But a recent imaging study by researchers at <strong>the</strong><br />
University of Cincinnati Medical Center found that this distinction ends in <strong>the</strong><br />
mid-20s when <strong>the</strong> brain shifts to use both sides in language processing.<br />
The story of teen brain development lies in a process called myelinization, in which a<br />
layer of fat coats wire-like fibers connecting regions of <strong>the</strong> brain, back-to-front, sideto-side,<br />
and everywhere in between. Over <strong>time</strong>, this makes <strong>the</strong> operation of <strong>the</strong><br />
brain more precise and efficient, affecting not just thinking and problem-solving, but<br />
also coordination and mastery of skills ranging from throwing a baseball to playing<br />
<strong>the</strong> trombone.<br />
But <strong>the</strong>re's a price <strong>for</strong> this greater efficiency -brain cells that aren't hooked up to<br />
o<strong>the</strong>r parts tend to get killed off.<br />
"If <strong>the</strong>y're not on <strong>the</strong> network, <strong>the</strong>y die and <strong>the</strong>ir place is taken up with cerebral<br />
fluid. This goes on well beyond age 18," said Dr. David Fassler, a psychiatrist at <strong>the</strong><br />
University of Vermont.<br />
Even in <strong>adult</strong>hood, <strong>the</strong> wiring job is not completely done. Imaging done on <strong>the</strong><br />
brains of people in <strong>the</strong>ir 40s and 50s show <strong>the</strong>re's ano<strong>the</strong>r surge of connections<br />
being made, perhaps in response to menopause or to prepare <strong>the</strong> brain to better<br />
compensate <strong>for</strong> <strong>the</strong> loss of brain cells as we age.<br />
Still, it's a slow, arduous road to maturity and insight <strong>for</strong> teens.<br />
"We have some new insight into <strong>the</strong> 16 year-old that doesn't think twice about<br />
getting in a car with a friend who's been drinking, but <strong>the</strong>y're still not going to<br />
appreciate <strong>adult</strong>s arguments <strong>for</strong> why <strong>the</strong>y shouldn't," said Fassler.<br />
At <strong>the</strong> National Institute of Mental Health, Dr. Jay Giedd, who helps run <strong>the</strong> ongoing<br />
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New research shows stark differences in teen brains<br />
imaging studies that first detected <strong>the</strong> middle school growth spurt, said <strong>the</strong> new<br />
understanding of teen brains "argues <strong>for</strong> doing a lot of things as a teenager. You are<br />
hard-wiring you brain in adolescence. Do you want to hard-wire it <strong>for</strong> sports and<br />
playing music and doing ma<strong>the</strong>matics, or <strong>for</strong> lying on <strong>the</strong> couch in front of <strong>the</strong><br />
television"<br />
The new understanding of adolescent brains leads to questions of ethics and<br />
legalities.<br />
The Supreme Court already has decided that people should not be executed <strong>for</strong><br />
crimes committed when <strong>the</strong>y were age 15 or younger, and in <strong>the</strong> fall is scheduled to<br />
consider whe<strong>the</strong>r <strong>the</strong> restriction should be extended to everyone under 18.<br />
Two years ago, <strong>the</strong> court banned execution of mentally retarded people because of<br />
deficiencies that "diminish <strong>the</strong>ir personal culpability."<br />
"With <strong>the</strong> new biological explanation that adolescent brains are different, we think<br />
<strong>the</strong>re's scientific evidence that <strong>the</strong>y, too, are less culpable," said Stephen Harper, an<br />
adjunct professor of juvenile justice at <strong>the</strong> University of Miami School of Law who<br />
specializes in capital cases.<br />
Gur said some scientists would put off <strong>the</strong> age of legal majority to 22 or 23, and said<br />
<strong>the</strong>re will likely be considerable debate over how to tell when a person's brain<br />
physically looks like an <strong>adult</strong>'s as imaging research continues and ef<strong>for</strong>ts to set<br />
standards and norms develop.<br />
Fassler predicts that within a decade, brain images will be sophisticated enough to<br />
"help us determine <strong>the</strong> age <strong>for</strong> appropriate treatment of addictions and <strong>the</strong>rapy<br />
models <strong>for</strong> <strong>adult</strong>s and adolescents with disorders."<br />
O<strong>the</strong>r researchers say that while it's possible to gain general understanding about<br />
brain development and function from <strong>the</strong> images, <strong>the</strong> notion that medicine, law<br />
en<strong>for</strong>cement or anyone else should work from some ideal, normal brain model is<br />
troubling.<br />
"Each individual is not an exact map, and <strong>the</strong> difficulties in determining what <strong>the</strong><br />
range of variations are is really dangerous. The data is incredibly easy to be overinterpreted,"<br />
said Sonia Miller, a New York attorney who specializes in cases dealing<br />
with new technologies.<br />
Some courts are already accepting brain scans as evidence of a person's mental<br />
capacity in criminal cases, she said, and "as <strong>the</strong> neuroscience of intentional behavior<br />
develops, <strong>the</strong> way we assign responsibility and blame will be challenged. This raises<br />
a lot of questions about how much neural privacy can we expect, how much <strong>the</strong><br />
authorities can get into your brain."<br />
Dr. Peter Bandettini, a brain-imaging researcher at <strong>the</strong> National Institutes of Health,<br />
said <strong>the</strong> science of understanding what small structures and chemicals are doing<br />
within <strong>the</strong> brain is far from a gold standard <strong>for</strong> mental function or age.<br />
"Right now, I personally think you'd get more in<strong>for</strong>mation about a person's mental<br />
age by going to a set of behavioral tests. But I'd agree that as <strong>the</strong>se technologies<br />
become more powerful, <strong>the</strong>re's going to be a greater need <strong>for</strong> checks and balances<br />
to determine how <strong>the</strong> imaging in<strong>for</strong>mation should be used."<br />
On <strong>the</strong> Net:<br />
●<br />
●<br />
●<br />
●<br />
http://www.nimh.nih.gov/<br />
http://www.dana.org/<br />
http://www.aap.org/<br />
http://www.psych.org/<br />
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What Makes Teens Tick; A flood of hormones, sure. But also a host of struct...plain <strong>the</strong> behaviors that make adolescence so exciting--and so exasperating<br />
What Makes Teens Tick; A flood of hormones,<br />
sure. But also a host of structural changes in <strong>the</strong><br />
brain. Can those explain <strong>the</strong> behaviors that<br />
make adolescence so exciting--and so<br />
exasperating<br />
Advanced search |<br />
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Time Magazine<br />
Written by: Time Magazine<br />
Time Magazine<br />
May 10, 2004<br />
What Makes Teens Tick; A flood of hormones, sure. But also a<br />
host of structural changes in <strong>the</strong> brain. Can those explain <strong>the</strong><br />
behaviors that make adolescence so exciting--and so<br />
exasperating<br />
By Claudia Wallis; Kristina Dell, with reporting by Alice Park/New York<br />
Five young men in sneakers and jeans troop into a waiting room at <strong>the</strong> National<br />
Institutes of Health Clinical Center in Be<strong>the</strong>sda, Md., and drape <strong>the</strong>mselves all over<br />
<strong>the</strong> chairs in classic collapsed-teenager mode, trailing backpacks, a CD player and a<br />
laptop loaded with computer games. It's midafternoon, and <strong>the</strong>y are, of course,<br />
tired, but even so <strong>the</strong>ir presence adds a jangly, hormonal buzz to <strong>the</strong> bland,<br />
institutional setting. Fair-haired twins Corey and Skyler Mann, 16, and <strong>the</strong>ir burlier<br />
big bro<strong>the</strong>rs Anthony and Brandon, 18, who are also twins, plus eldest bro<strong>the</strong>r<br />
Christopher, 22, are here to have <strong>the</strong>ir heads examined. Literally. The five bro<strong>the</strong>rs<br />
from Orem, Utah, are <strong>the</strong> latest recruits to a giant study that's been going on in this<br />
building since 1991. Its goal: to determine how <strong>the</strong> brain develops from childhood<br />
into adolescence and on into early <strong>adult</strong>hood.<br />
It is <strong>the</strong> project of Dr. Jay Giedd (pronounced Geed), chief of brain imaging in <strong>the</strong><br />
child psychiatry branch at <strong>the</strong> National Institute of Mental Health. Giedd, 43, has<br />
devoted <strong>the</strong> past 13 years to peering inside <strong>the</strong> heads of 1,800 kids and teenagers<br />
using high-powered magnetic resonance imaging (MRI). For each volunteer, he<br />
creates a unique photo album, taking MRI snapshots every two years and building a<br />
record as <strong>the</strong> brain morphs and grows. Giedd started out investigating <strong>the</strong><br />
developmental origins of attention-deficit/hyperactivity disorder (ADHD) and autism<br />
("I was going alphabetically," he jokes) but soon discovered that so little was known<br />
about how <strong>the</strong> brain is supposed to develop that it was impossible to figure out<br />
where things might be going wrong. In a way, <strong>the</strong> vast project that has become his<br />
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What Makes Teens Tick; A flood of hormones, sure. But also a host of struct...plain <strong>the</strong> behaviors that make adolescence so exciting--and so exasperating<br />
life's work is nothing more than an attempt to establish a gigantic control group. "It<br />
turned out that normal brains were so interesting in <strong>the</strong>mselves," he marvels. "And<br />
<strong>the</strong> adolescent studies have been <strong>the</strong> most surprising of all."<br />
Be<strong>for</strong>e <strong>the</strong> imaging studies by Giedd and his collaborators at UCLA, Harvard, <strong>the</strong><br />
Montreal Neurological Institute and a dozen o<strong>the</strong>r institutions, most scientists<br />
believed <strong>the</strong> brain was largely a finished product by <strong>the</strong> <strong>time</strong> a child reached <strong>the</strong> age<br />
of 12. Not only is it full-grown in size, Giedd explains, but "in a lot of psychological<br />
literature, traced back to [Swiss psychologist Jean] Piaget, <strong>the</strong> highest rung in <strong>the</strong><br />
ladder of cognitive development was about age 12--<strong>for</strong>mal operations." In <strong>the</strong> past,<br />
children entered initiation rites and started learning trades at about <strong>the</strong> onset of<br />
puberty. Some <strong>the</strong>orists concluded from this that <strong>the</strong> idea of adolescence was an<br />
artificial construct, a phenomenon invented in <strong>the</strong> post--Industrial Revolution years.<br />
Giedd's scanning studies proved what every parent of a teenager knows: not only is<br />
<strong>the</strong> brain of <strong>the</strong> adolescent far from mature, but both gray and white matter undergo<br />
extensive structural changes well past puberty. "When we started," says Giedd, "we<br />
thought we'd follow kids until about 18 or 20. If we had to pick a number now, we'd<br />
probably go to age 25."<br />
Now that MRI studies have cracked open a window on <strong>the</strong> developing brain,<br />
researchers are looking at how <strong>the</strong> newly detected physiological changes might<br />
account <strong>for</strong> <strong>the</strong> adolescent behaviors so familiar to parents: emotional outbursts,<br />
reckless risk taking and rule breaking, and <strong>the</strong> impassioned pursuit of sex, drugs and<br />
rock 'n' roll. Some experts believe <strong>the</strong> structural changes seen at adolescence may<br />
explain <strong>the</strong> timing of such major mental illnesses as schizophrenia and bipolar<br />
disorder. These diseases typically begin in adolescence and contribute to <strong>the</strong> high<br />
rate of teen suicide. Increasingly, <strong>the</strong> wild conduct once blamed on "raging<br />
hormones" is being seen as <strong>the</strong> by-product of two factors: a surfeit of hormones,<br />
yes, but also a paucity of <strong>the</strong> cognitive controls needed <strong>for</strong> mature behavior.<br />
In recent years, Giedd has shifted his focus to twins, which is why <strong>the</strong> Manns are<br />
such exciting recruits. Although most brain development seems to follow a set plan,<br />
with changes following cues that are preprogrammed into genes, o<strong>the</strong>r, subtler<br />
changes in gray matter reflect experience and environment. By following twins, who<br />
start out with identical--or, in fraternal twins, similar--programming but <strong>the</strong>n diverge<br />
as life takes <strong>the</strong>m on different paths, he hopes to tease apart <strong>the</strong> influences of<br />
nature and nurture. Ultimately, he hopes to find, <strong>for</strong> instance, that Anthony Mann's<br />
plan to become a pilot and Brandon's to study law will lead to brain differences that<br />
are detectable on future MRIs. The brain, more than any o<strong>the</strong>r organ, is where<br />
experience becomes flesh.<br />
Throughout <strong>the</strong> afternoon, <strong>the</strong> Mann bro<strong>the</strong>rs take turns completing tests of<br />
intelligence and cognitive function. Between sessions <strong>the</strong>y occasionally needle one<br />
ano<strong>the</strong>r in <strong>the</strong> waiting room. "If <strong>the</strong> o<strong>the</strong>r person is in a bad mood, you've got to<br />
provoke it," Anthony asserts slyly. Their mo<strong>the</strong>r Nancy Mann, a sunny paragon of<br />
patience who has three daughters in addition to <strong>the</strong> five boys, smiles and rolls her<br />
eyes.<br />
Shortly be<strong>for</strong>e 5 p.m., <strong>the</strong> Manns head downstairs to <strong>the</strong> imaging floor to meet <strong>the</strong><br />
magnet. Giedd, a trim, energetic man with a reddish beard, twinkly blue eyes and an<br />
impish sense of humor, greets Anthony and tells him what to expect. He asks<br />
Anthony to remove his watch, his necklace and a high school ring, labeled KEEPER.<br />
Does Anthony have any metal in his body Any piercings Not this clean-cut, soccerplaying<br />
Mormon. Giedd tapes a vitamin E capsule onto Anthony's left cheek and one<br />
in each ear. He explains that <strong>the</strong> oil-filled capsules are opaque to <strong>the</strong> scanner and<br />
will define a plane on <strong>the</strong> images, as well as help researchers tell left from right. The<br />
scanning will take about 15 minutes, during which Anthony must lie completely still.<br />
Dressed in a red sweat shirt, jeans and white K-Swiss sneakers, he stretches out on<br />
<strong>the</strong> examining table and slides his head into <strong>the</strong> machine's giant magnetic ring.<br />
MRI, Giedd points out, "made studying healthy kids possible" because <strong>the</strong>re's no<br />
radiation involved. (Be<strong>for</strong>e MRI, brain development was studied mostly by using<br />
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cadavers.) Each of <strong>the</strong> Mann boys will be scanned three <strong>time</strong>s. The first scan is a<br />
quick survey that lasts one minute. The second lasts two minutes and looks <strong>for</strong> any<br />
damage or abnormality. The third is 10 minutes long and taken at maximum<br />
resolution. It's <strong>the</strong> money shot. Giedd watches as Anthony's brain appears in cross<br />
section on a computer screen. The machine scans 124 slices, each as thin as a dime.<br />
It will take 20 hours of computer <strong>time</strong> to process <strong>the</strong> images, but <strong>the</strong> analysis is<br />
done by humans, says Giedd. "The human brain is still <strong>the</strong> best at pattern<br />
recognition," he marvels.<br />
Some people get nervous as <strong>the</strong> MRI machine clangs noisily. Claustrophobes panic.<br />
Anthony, lying still in <strong>the</strong> soul of <strong>the</strong> machine, simply falls asleep.<br />
CONSTRUCTION AHEAD<br />
One reason scientists have been surprised by <strong>the</strong> ferment in <strong>the</strong> teenage brain is<br />
that <strong>the</strong> brain grows very little over <strong>the</strong> course of childhood. By <strong>the</strong> <strong>time</strong> a child is 6,<br />
it is 90% to 95% of its <strong>adult</strong> size. As a matter of fact, we are born equipped with<br />
most of <strong>the</strong> neurons our brain will ever have--and that's fewer than we have in<br />
utero. Humans achieve <strong>the</strong>ir maximum brain-cell density between <strong>the</strong> third and sixth<br />
month of gestation--<strong>the</strong> culmination of an explosive period of prenatal neural<br />
growth. During <strong>the</strong> final months be<strong>for</strong>e birth, our brains undergo a dramatic pruning<br />
in which unnecessary brain cells are eliminated. Many neuroscientists now believe<br />
that autism is <strong>the</strong> result of insufficient or abnormal prenatal pruning.<br />
What Giedd's long-term studies have documented is that <strong>the</strong>re is a second wave of<br />
proliferation and pruning that occurs later in childhood and that <strong>the</strong> final, critical part<br />
of this second wave, affecting some of our highest mental functions, occurs in <strong>the</strong><br />
late teens. Unlike <strong>the</strong> prenatal changes, this neural waxing and waning alters not <strong>the</strong><br />
number of nerve cells but <strong>the</strong> number of connections, or synapses, between <strong>the</strong>m.<br />
When a child is between <strong>the</strong> ages of 6 and 12, <strong>the</strong> neurons grow bushier, each<br />
making dozens of connections to o<strong>the</strong>r neurons and creating new pathways <strong>for</strong> nerve<br />
signals. The thickening of all this gray matter--<strong>the</strong> neurons and <strong>the</strong>ir branchlike<br />
dendrites--peaks when girls are about 11 and boys 12 1/2, at which point a serious<br />
round of pruning is under way. Gray matter is thinned out at a rate of about 0.7% a<br />
year, tapering off in <strong>the</strong> early 20s. At <strong>the</strong> same <strong>time</strong>, <strong>the</strong> brain's white matter<br />
thickens. The white matter is composed of fatty myelin sheaths that encase axons<br />
and, like insulation on a wire, make nerve-signal transmissions faster and more<br />
efficient. With each passing year (maybe even up to age 40) myelin sheaths thicken,<br />
much like tree rings. During adolescence, says Giedd, summing up <strong>the</strong> process, "you<br />
get fewer but faster connections in <strong>the</strong> brain." The brain becomes a more efficient<br />
machine, but <strong>the</strong>re is a trade-off: it is probably losing some of its raw potential <strong>for</strong><br />
learning and its ability to recover from trauma.<br />
Most scientists believe that <strong>the</strong> pruning is guided both by genetics and by a use-it-orlose-it<br />
principle. Nobel prizewinning neuroscientist Gerald Edelman has described<br />
that process as "neural Darwinism"--survival of <strong>the</strong> fittest (or most used) synapses.<br />
How you spend your <strong>time</strong> may be critical. Research shows, <strong>for</strong> instance, that<br />
practicing piano quickly thickens neurons in <strong>the</strong> brain regions that control <strong>the</strong><br />
fingers. Studies of London cab drivers, who must memorize all <strong>the</strong> city's streets,<br />
show that <strong>the</strong>y have an unusually large hippocampus, a structure involved in<br />
memory. Giedd's research suggests that <strong>the</strong> cerebellum, an area that coordinates<br />
both physical and mental activities, is particularly responsive to experience, but he<br />
warns that it's too soon to know just what drives <strong>the</strong> buildup and pruning phases.<br />
He's hoping his studies of twins will help answer such questions: "We're looking at<br />
what <strong>the</strong>y eat, how <strong>the</strong>y spend <strong>the</strong>ir <strong>time</strong>--is it video games or sports Now <strong>the</strong> fun<br />
begins," he says.<br />
No matter how a particular brain turns out, its development proceeds in stages,<br />
generally from back to front. Some of <strong>the</strong> brain regions that reach maturity earliest--<br />
through proliferation and pruning--are those in <strong>the</strong> back of <strong>the</strong> brain that mediate<br />
direct contact with <strong>the</strong> environment by controlling such sensory functions as vision,<br />
hearing, touch and spatial processing. Next are areas that coordinate those<br />
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functions: <strong>the</strong> part of <strong>the</strong> brain that helps you know where <strong>the</strong> light switch is in your<br />
bathroom even if you can't see it in <strong>the</strong> middle of <strong>the</strong> night. The very last part of <strong>the</strong><br />
brain to be pruned and shaped to its <strong>adult</strong> dimensions is <strong>the</strong> prefrontal cortex, home<br />
of <strong>the</strong> so-called executive functions--planning, setting priorities, organizing thoughts,<br />
suppressing impulses, weighing <strong>the</strong> consequences of one's actions. In o<strong>the</strong>r words,<br />
<strong>the</strong> final part of <strong>the</strong> brain to grow up is <strong>the</strong> part capable of deciding, I'll finish my<br />
homework and take out <strong>the</strong> garbage, and <strong>the</strong>n I'll IM my friends about seeing a<br />
movie.<br />
"Scientists and <strong>the</strong> general public had attributed <strong>the</strong> bad decisions teens make to<br />
hormonal changes," says Elizabeth Sowell, a UCLA neuroscientist who has done<br />
seminal MRI work on <strong>the</strong> developing brain. "But once we started mapping where and<br />
when <strong>the</strong> brain changes were happening, we could say, Aha, <strong>the</strong> part of <strong>the</strong> brain<br />
that makes teenagers more responsible is not finished maturing yet."<br />
RAGING HORMONES<br />
Hormones, however, remain an important part of <strong>the</strong> teen-brain story. Right about<br />
<strong>the</strong> <strong>time</strong> <strong>the</strong> brain switches from proliferating to pruning, <strong>the</strong> body comes under <strong>the</strong><br />
hormonal assault of puberty. (Research suggests that <strong>the</strong> two events are not closely<br />
linked because brain development proceeds on schedule even when a child<br />
experiences early or late puberty.) For years, psychologists attributed <strong>the</strong> intense,<br />
combustible emotions and unpredictable behavior of teens to this biochemical<br />
onslaught. And new research adds fresh support. At puberty, <strong>the</strong> ovaries and testes<br />
begin to pour estrogen and testosterone into <strong>the</strong> bloodstream, spurring <strong>the</strong><br />
development of <strong>the</strong> reproductive system, causing hair to sprout in <strong>the</strong> armpits and<br />
groin, wreaking havoc with <strong>the</strong> skin, and shaping <strong>the</strong> body to its <strong>adult</strong> contours. At<br />
<strong>the</strong> same <strong>time</strong>, testosterone-like hormones released by <strong>the</strong> adrenal glands, located<br />
near <strong>the</strong> kidneys, begin to circulate. Recent discoveries show that <strong>the</strong>se adrenal sex<br />
hormones are extremely active in <strong>the</strong> brain, attaching to receptors everywhere and<br />
exerting a direct influence on serotonin and o<strong>the</strong>r neurochemicals that regulate<br />
mood and excitability.<br />
The sex hormones are especially active in <strong>the</strong> brain's emotional center--<strong>the</strong> limbic<br />
system. This creates a "tinderbox of emotions," says Dr. Ronald Dahl, a psychiatrist<br />
at <strong>the</strong> University of Pittsburgh. Not only do feelings reach a flash point more easily,<br />
but adolescents tend to seek out situations where <strong>the</strong>y can allow <strong>the</strong>ir emotions and<br />
passions to run wild. "Adolescents are actively looking <strong>for</strong> experiences to create<br />
intense feelings," says Dahl. "It's a very important hint that <strong>the</strong>re is some particular<br />
hormone-brain relationship contributing to <strong>the</strong> appetite <strong>for</strong> thrills, strong sensations<br />
and excitement." This thrill seeking may have evolved to promote exploration, an<br />
eagerness to leave <strong>the</strong> nest and seek one's own path and partner. But in a world<br />
where fast cars, illicit drugs, gangs and dangerous liaisons beckon, it also puts <strong>the</strong><br />
teenager at risk.<br />
That is especially so because <strong>the</strong> brain regions that put <strong>the</strong> brakes on risky,<br />
impulsive behavior are still under construction. "The parts of <strong>the</strong> brain responsible<br />
<strong>for</strong> things like sensation seeking are getting turned on in big ways around <strong>the</strong> <strong>time</strong> of<br />
puberty," says Temple University psychologist Laurence Steinberg. "But <strong>the</strong> parts <strong>for</strong><br />
exercising judgment are still maturing throughout <strong>the</strong> course of adolescence. So<br />
you've got this <strong>time</strong> gap between when things impel kids toward taking risks early in<br />
adolescence, and when things that allow people to think be<strong>for</strong>e <strong>the</strong>y act come online.<br />
It's like turning on <strong>the</strong> engine of a car without a skilled driver at <strong>the</strong> wheel."<br />
DUMB DECISIONS<br />
Increasingly, psychologists like Steinberg are trying to connect <strong>the</strong> familiar patterns<br />
of adolescents' wacky behavior to <strong>the</strong> new findings about <strong>the</strong>ir evolving brain<br />
structure. It's not always easy to do. "In all likelihood, <strong>the</strong> behavior is changing<br />
because <strong>the</strong> brain is changing," he says. "But that is still a bit of a leap." A critical<br />
tool in making that leap is functional magnetic resonance imaging (fMRI). While<br />
ordinary MRI reveals brain structure, fMRI actually shows brain activity while<br />
subjects are doing assigned tasks.<br />
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At McLean Hospital in Belmont, Mass., Harvard neuropsychologist Deborah Yurgelun-<br />
Todd did an elegant series of FMRI experiments in which both kids and <strong>adult</strong>s were<br />
asked to identity <strong>the</strong> emotions displayed in photographs of faces. "In doing <strong>the</strong>se<br />
tasks," she says, "kids and young adolescents rely heavily on <strong>the</strong> amygdala, a<br />
structure in <strong>the</strong> temporal lobes associated with emotional and gut reactions. Adults<br />
rely less on <strong>the</strong> amygdala and more on <strong>the</strong> frontal lobe, a region associated with<br />
planning and judgment." While <strong>adult</strong>s make few errors in assessing <strong>the</strong> photos, kids<br />
under 14 tend to make mistakes. In particular, <strong>the</strong>y identify fearful expressions as<br />
angry, confused or sad. By following <strong>the</strong> same kids year after year, Yurgelun-Todd<br />
has been able to watch <strong>the</strong>ir brain-activity pattern--and <strong>the</strong>ir judgment--mature.<br />
Fledgling physiology, she believes, may explain why adolescents so frequently<br />
misread emotional signals, seeing anger and hostility where none exists. Teenage<br />
ranting ("That teacher hates me!") can be better understood in this light.<br />
At Temple University, Steinberg has been studying ano<strong>the</strong>r kind of judgment: risk<br />
assessment. In an experiment using a driving-simulation game, he studies teens and<br />
<strong>adult</strong>s as <strong>the</strong>y decide whe<strong>the</strong>r to run a yellow light. Both sets of subjects, he found,<br />
make safe choices when playing alone. But in group play, teenagers start to take<br />
more risks in <strong>the</strong> presence of <strong>the</strong>ir friends, while those over age 20 don't show much<br />
change in <strong>the</strong>ir behavior. "With this manipulation," says Steinberg, "we've shown<br />
that age differences in decision making and judgment may appear under conditions<br />
that are emotionally arousing or have high social impact." Most teen crimes, he says,<br />
are committed by kids in packs.<br />
O<strong>the</strong>r researchers are exploring how <strong>the</strong> adolescent propensity <strong>for</strong> uninhibited risk<br />
taking propels teens to experiment with drugs and alcohol. Traditionally,<br />
psychologists have attributed this experimentation to peer pressure, teenagers'<br />
attraction to novelty and <strong>the</strong>ir roaring interest in loosening sexual inhibitions. But<br />
researchers have raised <strong>the</strong> possibility that rapid changes in dopamine-rich areas of<br />
<strong>the</strong> brain may be an additional factor in making teens vulnerable to <strong>the</strong> stimulating<br />
and addictive effects of drugs and alcohol. Dopamine, <strong>the</strong> brain chemical involved in<br />
motivation and in rein<strong>for</strong>cing behavior, is particularly abundant and active in <strong>the</strong><br />
teen years.<br />
Why is it so hard to get a teenager off <strong>the</strong> couch and working on that all important<br />
college essay You might blame it on <strong>the</strong>ir immature nucleus accumbens, a region in<br />
<strong>the</strong> frontal cortex that directs motivation to seek rewards. James Bjork at <strong>the</strong><br />
National Institute on Alcohol Abuse and Alcoholism has been using fMRI to study<br />
motivation in a challenging gambling game. He found that teenagers have less<br />
activity in this region than <strong>adult</strong>s do. "If adolescents have a motivational deficit, it<br />
may mean that <strong>the</strong>y are prone to engaging in behaviors that have ei<strong>the</strong>r a really<br />
high excitement factor or a really low ef<strong>for</strong>t factor, or a combination of both." Sound<br />
familiar Bjork believes his work may hold valuable lessons <strong>for</strong> parents and society.<br />
"When presenting suggestions, anything parents can do to emphasize more<br />
immediate payoffs will be more effective," he says. To persuade a teen to quit<br />
drinking, <strong>for</strong> example, he suggests stressing something immediate and tangible--<strong>the</strong><br />
danger of getting kicked off <strong>the</strong> football team, say--ra<strong>the</strong>r than a future on skid row.<br />
Persuading a teenager to go to bed and get up on a reasonable schedule is ano<strong>the</strong>r<br />
matter entirely. This kind of decision making has less to do with <strong>the</strong> frontal lobe than<br />
with <strong>the</strong> pineal gland at <strong>the</strong> base of <strong>the</strong> brain. As night<strong>time</strong> approaches and daylight<br />
recedes, <strong>the</strong> pineal gland produces melatonin, a chemical that signals <strong>the</strong> body to<br />
begin shutting down <strong>for</strong> sleep. Studies by Mary Carskadon at Brown University have<br />
shown that it takes longer <strong>for</strong> melatonin levels to rise in teenagers than in younger<br />
kids or in <strong>adult</strong>s, regardless of exposure to light or stimulating activities. "The brain's<br />
program <strong>for</strong> starting night<strong>time</strong> is later," she explains.<br />
PRUNING PROBLEMS<br />
The new discoveries about teenage brain development have prompted all sorts of<br />
questions and <strong>the</strong>ories about <strong>the</strong> timing of childhood mental illness and cognitive<br />
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disorders. Some scientists now believe that ADHD and Tourette's syndrome, which<br />
typically appear by <strong>the</strong> <strong>time</strong> a child reaches age 7, may be related to <strong>the</strong> brain<br />
proliferation period. Though both disorders have genetic roots, <strong>the</strong> rapid growth of<br />
brain tissue in early childhood, especially in regions rich in dopamine, "may set <strong>the</strong><br />
stage <strong>for</strong> <strong>the</strong> increase in motor activities and tics," says Dr. Martin Teicher, director<br />
of developmental biopsychiatry research at McLean Hospital. "When it starts to<br />
prune in adolescence, you often see symptoms recede."<br />
Schizophrenia, on <strong>the</strong> o<strong>the</strong>r hand, makes its appearance at about <strong>the</strong> <strong>time</strong> <strong>the</strong><br />
prefrontal cortex is getting pruned. "Many people have speculated that schizophrenia<br />
may be due to an abnormality in <strong>the</strong> pruning process," says Teicher. "Ano<strong>the</strong>r<br />
hypo<strong>the</strong>sis is that schizophrenia has a much earlier, prenatal origin, but as <strong>the</strong> brain<br />
prunes, it gets unmasked." MRI studies have shown that while <strong>the</strong> average teenager<br />
loses about 15% of his cortical gray matter, those who develop schizophrenia lose as<br />
much as 25%.<br />
WHAT'S A PARENT TO DO<br />
Brain scientists tend to be reluctant to make <strong>the</strong> leap from <strong>the</strong> laboratory to real-life,<br />
hard-core teenagers. Some feel a little burned by <strong>the</strong> way earlier neurological<br />
discoveries resulted in Baby Einstein tapes and o<strong>the</strong>r marketing schemes that<br />
misapplied <strong>the</strong>ir science. It is clear, however, that <strong>the</strong>re are implications in <strong>the</strong> new<br />
research <strong>for</strong> parents, educators and lawmakers.<br />
In light of what has been learned, it seems almost arbitrary that our society has<br />
decided that a young American is ready to drive a car at 16, to vote and serve in <strong>the</strong><br />
Army at 18 and to drink alcohol at 21. Giedd says <strong>the</strong> best estimate <strong>for</strong> when <strong>the</strong><br />
brain is truly mature is 25, <strong>the</strong> age at which you can rent a car. "Avis must have<br />
some pretty sophisticated neuroscientists," he jokes. Now that we have scientific<br />
evidence that <strong>the</strong> adolescent brain is not quite up to scratch, some legal scholars<br />
and child advocates argue that minors should never be tried as <strong>adult</strong>s and should be<br />
spared <strong>the</strong> death penalty. Last year, in an official statement that summarized<br />
current research on <strong>the</strong> adolescent brain, <strong>the</strong> American Bar Association urged all<br />
state legislatures to ban <strong>the</strong> death penalty <strong>for</strong> juveniles. "For social and biological<br />
reasons," it read, "teens have increased difficulty making mature decisions and<br />
understanding <strong>the</strong> consequences of <strong>the</strong>ir actions."<br />
Most parents, of course, know this instinctively. Still, it's useful to learn that teenage<br />
behavior is not just a matter of willful pigheadedness or determination to drive you<br />
crazy--though <strong>the</strong>se, too, can be factors. "There's a debate over how much<br />
conscious control kids have," says Giedd, who has four "teenagers in training" of his<br />
own. "You can tell <strong>the</strong>m to shape up or ship out, but making mistakes is part of how<br />
<strong>the</strong> brain optimally grows." It might be more useful to help <strong>the</strong>m make up <strong>for</strong> what<br />
<strong>the</strong>ir brain still lacks by providing structure, organizing <strong>the</strong>ir <strong>time</strong>, guiding <strong>the</strong>m<br />
through tough decisions (even when <strong>the</strong>y resist) and applying those <strong>time</strong>-tested<br />
parental virtues: patience and love.<br />
--With reporting by Alice Park/New York<br />
INSIDE THE ADOLESCENT BRAIN<br />
The brain undergoes two major developmental spurts, one in <strong>the</strong> womb and <strong>the</strong><br />
second from childhood through <strong>the</strong> teen years, when <strong>the</strong> organ matures by fits and<br />
starts in a sequence that moves from <strong>the</strong> back of <strong>the</strong> brain to <strong>the</strong> front<br />
BRAIN AREA<br />
DESCRIPTION / DUTIES<br />
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CORPUS CALLOSUM<br />
PREFRONTAL CORTEX<br />
BASAL GANGLIA<br />
AMYGDALA<br />
CEREBELLUM<br />
Thought to be involved in problem<br />
solving and creativity, this bundle<br />
of nerve fibers connects <strong>the</strong> left<br />
and right hemispheres of <strong>the</strong> brain.<br />
During adolescence, <strong>the</strong> nerve<br />
fibers thicken and process<br />
in<strong>for</strong>mation more and more<br />
efficiently<br />
The CEO of <strong>the</strong> brain, also called<br />
<strong>the</strong> area of sober second thought,<br />
is <strong>the</strong> last part of <strong>the</strong> brain to<br />
mature-which may be why teens<br />
get into so much trouble. Located<br />
just behind <strong>the</strong> <strong>for</strong>ehead, <strong>the</strong><br />
prefrontal cortex grows during <strong>the</strong><br />
preteen years and <strong>the</strong>n shrinks as<br />
neural connections are pruned<br />
during adolescence<br />
Larger in females than in males,<br />
this part of <strong>the</strong> brain acts like a<br />
secretary to <strong>the</strong> prefrontal cortex<br />
by helping it prioritize in<strong>for</strong>mation.<br />
The basal ganglia and prefrontal<br />
cortex are tightly connected: at<br />
nearly <strong>the</strong> same <strong>time</strong>, <strong>the</strong>y grow<br />
neuron connections and <strong>the</strong>n prune<br />
<strong>the</strong>m. This area of <strong>the</strong> brain is also<br />
active in small and large motor<br />
movements, so it may be important<br />
to expose preteens to music and<br />
sports while it is growing<br />
This is <strong>the</strong> emotional center of <strong>the</strong><br />
brain, home to such primal feelings<br />
as fear and rage. In processing<br />
emotional in<strong>for</strong>mation, teens tend<br />
to rely more heavily on <strong>the</strong><br />
amygdala. Adults depend more on<br />
<strong>the</strong> rational prefrontal cortex, a<br />
part of <strong>the</strong> brain that is<br />
underdeveloped in teens. That may<br />
explain why adolescents often react<br />
more impulsively than <strong>adult</strong>s<br />
Long thought to play a role in<br />
physical coordination, this area<br />
may also regulate certain thought<br />
processes. More sensitive to<br />
environment than to heredity, <strong>the</strong><br />
cerebellum supports activities of<br />
higher learning like ma<strong>the</strong>matics,<br />
music and advanced social skills.<br />
New research shows that it changes<br />
dramatically during adolescence,<br />
increasing <strong>the</strong> number of neurons<br />
and <strong>the</strong> complexity of <strong>the</strong>ir<br />
connections. The cerebellum is <strong>the</strong><br />
only part of <strong>the</strong> brain that<br />
continues growing well into <strong>the</strong><br />
early 20s<br />
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What Makes Teens Tick; A flood of hormones, sure. But also a host of struct...plain <strong>the</strong> behaviors that make adolescence so exciting--and so exasperating<br />
NERVE PROLIFERATION...<br />
By age 11 <strong>for</strong> girls and 12 1/2 <strong>for</strong><br />
boys, <strong>the</strong> neurons in <strong>the</strong> front of<br />
<strong>the</strong> brain have <strong>for</strong>med thousands of<br />
new connections. Over <strong>the</strong> next few<br />
years, most of <strong>the</strong>se links will be<br />
pruned<br />
... AND PRUNING Those that are used and rein<strong>for</strong>ced<strong>the</strong><br />
pathways involved in language,<br />
<strong>for</strong> example-will be streng<strong>the</strong>ned,<br />
while <strong>the</strong> ones that aren't used will<br />
die out<br />
Sources: Dr. Jay Giedd, chief of brain imaging, child psychiatry branch, NIMH; Paul<br />
Thompson, Andrew Lee, Kiralee Hayashi and Arthur Toga, UCLA Lab of Neuro<br />
Imaging; Nitin Gogtay and Judy Rapoport, child psychiatry branch, NIMH<br />
Text by Kristina Dell<br />
Home | About DPIC | Privacy Policy<br />
©2006 Death Penalty In<strong>for</strong>mation Center<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
Week of May 8, 2004; Vol. 165, No. 19 , p. 299<br />
Teen Brains on Trial<br />
The science of neural development tangles with <strong>the</strong> juvenile<br />
death penalty<br />
Bruce Bower<br />
Science News<br />
Web<br />
Later this year, <strong>the</strong> U.S. Supreme Court will hear arguments about whe<strong>the</strong>r<br />
federal law should continue to permit executions of 16- and 17-year-olds<br />
convicted of murder. On this life-or-death issue, controversial legal and ethical<br />
views on teenagers' capacity to control <strong>the</strong>ir behavior and obey <strong>the</strong> law will<br />
take center stage. However, a relative newcomer to <strong>the</strong> debate—<strong>the</strong><br />
burgeoning science of brain development—may critically influence <strong>the</strong> high<br />
court's final decision.<br />
A coalition of psychiatric and legal organizations plans to submit a brief to <strong>the</strong><br />
justices contending that teenagers often make poor decisions and act<br />
impulsively because <strong>the</strong>ir brains haven't attained an <strong>adult</strong> level of<br />
organization. Consequently, <strong>the</strong> coalition argues, teenage killers are less<br />
culpable <strong>for</strong> <strong>the</strong>ir crimes than <strong>the</strong>ir <strong>adult</strong> counterparts are. Capital punishment<br />
of teens thus violates <strong>the</strong> constitutional amendment protecting citizens from<br />
cruel and unusual punishment.<br />
Science News<br />
<strong>for</strong> Kids<br />
Subscribe to an<br />
audio <strong>for</strong>mat<br />
"Our objection to <strong>the</strong> juvenile<br />
death penalty is rooted in <strong>the</strong> fact<br />
that adolescents' brains function<br />
in fundamentally different ways<br />
than <strong>adult</strong>s' brains do," says<br />
David Fassler, a psychiatrist at<br />
<strong>the</strong> University of Vermont in<br />
Burlington and a leader of <strong>the</strong><br />
ef<strong>for</strong>t to infuse capital-crime laws<br />
with brain science.<br />
Published by<br />
Age-related brain differences<br />
pack a real-world wallop, in his<br />
view. "From a biological<br />
perspective," Fassler asserts, "an<br />
anxious adolescent with a gun in<br />
a convenience store is more<br />
likely to perceive a threat and pull<br />
<strong>the</strong> trigger than is an anxious<br />
<strong>adult</strong> with a gun in <strong>the</strong> same<br />
store."<br />
MENTAL MATURITY New data on teens'<br />
unfinished brain development may aid ef<strong>for</strong>ts to get<br />
rid of <strong>the</strong> juvenile death penalty in <strong>the</strong> United <strong>States</strong>.<br />
PhotoDisk<br />
Fassler and two like-minded colleagues—neuropsychologist Ruben Gur of <strong>the</strong><br />
University of Pennsylvania in Philadelphia and lawyer Stephen Harper of <strong>the</strong><br />
University of Miami—spoke in March at a Washington, D.C., press conference<br />
convened by groups that included <strong>the</strong> American Psychiatric Association and<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
<strong>the</strong> American Bar Association.<br />
Yet <strong>the</strong> zeal with which <strong>the</strong>se organizations now wield brain studies to fight<br />
<strong>the</strong> juvenile death penalty masks a deep division among scientists about<br />
whe<strong>the</strong>r <strong>the</strong> data are ready <strong>for</strong> legal prime <strong>time</strong>.<br />
Some researchers agree that capital-punishment laws should incorporate<br />
what's known about teenagers' incomplete brain development, even if <strong>the</strong><br />
scientific story contains gaps. Don't excuse criminal behavior, <strong>the</strong>se scientists<br />
say, but acknowledge that adolescents who kill don't deserve <strong>the</strong> ultimate<br />
punishment.<br />
Members of ano<strong>the</strong>r camp argue that brain science doesn't belong in court<br />
because <strong>the</strong>re's no evidence linking specific characteristics of teens' brains to<br />
any legally relevant condition, such as impaired moral judgment or an inability<br />
to control murderous impulses.<br />
"Juvenile death sentences bo<strong>the</strong>r me, but this is an ethical issue," remarks<br />
Harvard University psychologist Jerome Kagan. "The brain data don't show<br />
that adolescents typically have reduced legal culpability <strong>for</strong> crimes."<br />
Frontal assault<br />
Plans to apply brain science to balance <strong>the</strong> scales of justice come at a <strong>time</strong><br />
when <strong>the</strong> juvenile death penalty is already on <strong>the</strong> defensive.<br />
As of January 2004, 29 states prohibited capital punishment of juveniles.<br />
Legislation to bar <strong>the</strong> death penalty <strong>for</strong> offenders under 18 years old is being<br />
considered in 14 additional states. Juvenile-death-penalty foes find this trend<br />
encouraging, since <strong>the</strong> Supreme Court justified its 2002 ruling against<br />
executing mentally retarded offenders by citing bans on that practice in 30<br />
states.<br />
Ano<strong>the</strong>r heartening sign <strong>for</strong> opponents of <strong>the</strong> juvenile death penalty occurred<br />
in December 2003, when a Virginia jury decided to sentence 17-year-old Lee<br />
Malvo to life in prison <strong>for</strong> his participation in <strong>the</strong> D.C.-area sniper killings.<br />
However, growing evidence that teenagers possess unfinished brains has<br />
received far more attention in <strong>the</strong> media than in <strong>the</strong> courts, Harper says. The<br />
legal system doesn't appreciate that young people's brains aren't fully<br />
equipped <strong>for</strong> making long-term plans and reining in impulses, he contends.<br />
Much of <strong>the</strong> concern about teen brains focuses on <strong>the</strong> frontal lobes. One way<br />
that scientists have learned about frontal lobe activity is by identifying<br />
associations between certain behaviors and increased frontal activity in<br />
healthy people. That work elaborated on previous studies of behavior<br />
changes in individuals who had suffered frontal-brain damage. Toge<strong>the</strong>r, <strong>the</strong><br />
findings implicate this neural region in regulating aggression, long-range<br />
planning, mental flexibility, abstract thinking, <strong>the</strong> capacity to hold in mind<br />
related pieces of in<strong>for</strong>mation, and perhaps moral judgment.<br />
O<strong>the</strong>r investigations indicate that <strong>the</strong> number of brain cells and <strong>the</strong>ir<br />
connections surge just be<strong>for</strong>e puberty. But through late adolescence, pruning<br />
of excess neurons and <strong>the</strong>ir linkages produces substantial declines in <strong>the</strong><br />
volume of <strong>the</strong> part of <strong>the</strong> brain, called <strong>the</strong> gray matter, that contains <strong>the</strong> cell<br />
bodies. There<strong>for</strong>e, <strong>the</strong> brain changes during adolescence mirror <strong>the</strong> initial<br />
wave of gray matter expansion in <strong>the</strong> womb and during <strong>the</strong> first 18 months of<br />
life, followed by a trimming-back period.<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
Using magnetic resonance imaging (MRI) scanners to probe <strong>the</strong> brains of<br />
healthy teenagers and young <strong>adult</strong>s, Elizabeth R. Sowell of <strong>the</strong> University of<br />
Cali<strong>for</strong>nia, Los Angeles (UCLA) and her colleagues reported in 1999 that<br />
myelin, <strong>the</strong> fatty tissue around nerve fibers that fosters transmission of<br />
electrical signals, accumulates especially slowly in <strong>the</strong> frontal lobe.<br />
The late phase of myelin <strong>for</strong>mation, occurring in teenagers, provides a neural<br />
basis <strong>for</strong> assuming that teens are less blameworthy <strong>for</strong> criminal acts that<br />
<strong>adult</strong>s are, Gur says. There's no way to say whe<strong>the</strong>r, <strong>for</strong> example, an<br />
individual 17-year-old possesses a fully mature brain. But <strong>the</strong> biological age of<br />
maturity generally falls around age 21 or 22, in Gur's view.<br />
Although 18 years old represents an arbitrary cutoff age <strong>for</strong> receiving a capital<br />
sentence, it's preferable to 17, according to Gur.<br />
"These brain data create reasonable doubt that a teenager can be held<br />
culpable <strong>for</strong> a crime to <strong>the</strong> same extent that an <strong>adult</strong> is," agrees neuroscientist<br />
J. Anthony Movshon of New York University.<br />
Fear factor<br />
Abigail A. Baird of Dartmouth College in Hanover, N.H., also suspects that<br />
delayed neural development undermines teens' judgment in ways that affect<br />
<strong>the</strong>ir legal standing. "There's no reason to say <strong>adult</strong>hood happens at age 18,"<br />
Baird says. Unlike Gur, however, she estimates that <strong>the</strong> brain achieves<br />
maturity at age 25 or 26.<br />
A 1999 investigation led by Baird and Deborah Yurgelun-Todd of Harvard<br />
Medical School in Boston raised <strong>the</strong> possibility that certain characteristics of<br />
teens' brains make it difficult <strong>for</strong> <strong>the</strong>m to recognize when o<strong>the</strong>r people are<br />
scared. They tested 12 teenagers, ages 12 to 17. A functional magnetic<br />
resonance imaging (fMRI) scanner measured changes throughout<br />
participants' brains in blood flow, which studies have indicated reflect dips and<br />
rises in neural activity. As <strong>the</strong> teens briefly viewed and identified fear in<br />
pictures of people who had intentionally tried to look scared, <strong>the</strong> researchers<br />
observed marked increases in activity of an almond-shaped inner-brain<br />
structure called <strong>the</strong> amygdala.<br />
Neuroscientists suspect that <strong>the</strong> amygdala is important <strong>for</strong> learning to attach<br />
emotional significance to facial expressions and o<strong>the</strong>r stimuli. However, <strong>the</strong><br />
results of Baird and Yurgelun-Todd indicated that <strong>the</strong>re may not be a simple<br />
relationship between amygdala activity and accurate face reading.<br />
The teen volunteers—all with active amygdalas—incorrectly identified one in<br />
four fear expressions, usually labeling <strong>the</strong>m as angry, sad, or confused.<br />
In an ensuing fMRI study directed by Yurgelun-Todd, 16 participants ages 12<br />
to 17 also erred frequently when labeling <strong>the</strong> emotion on fearful faces. Those<br />
less than 14 years old answered incorrectly about half <strong>the</strong> <strong>time</strong> and yet<br />
showed <strong>the</strong> most amygdala activity, while older teens made fewer errors and<br />
displayed less activity in <strong>the</strong> amygdala and more in <strong>the</strong> frontal lobes than <strong>the</strong><br />
younger participants did.<br />
Previous studies had found that, when given <strong>the</strong> same task, <strong>adult</strong>s label most<br />
fearful expressions correctly and exhibit much more activity in <strong>the</strong> frontal<br />
lobes than in <strong>the</strong> amygdala.<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
The results in <strong>the</strong>se small experiments remain preliminary. Even if <strong>the</strong> findings<br />
hold up, it's not clear whe<strong>the</strong>r young teens' difficulties in discerning fearful<br />
expressions stem from incomplete brain development or reflect unique duties<br />
assumed by <strong>the</strong> frontal lobes during adolescence. What's more, teenagers<br />
and <strong>adult</strong>s have yet to be similarly tested with faces displaying emotions o<strong>the</strong>r<br />
than fear.<br />
Baird's ongoing research suggests that <strong>the</strong> teen frontal brain indeed responds<br />
to spontaneous emotional expressions on <strong>the</strong> faces of friends and family<br />
members. "Kids say that <strong>the</strong> posed expressions we show <strong>the</strong>m look kind of<br />
weird," Baird says.<br />
O<strong>the</strong>r evidence suggests that mental efficiency in solving emotion-related<br />
tasks—indicated by <strong>the</strong> <strong>time</strong> taken to answer <strong>the</strong>m correctly—suffers with <strong>the</strong><br />
arrival of puberty, when gray matter volume in <strong>the</strong> frontal lobes hits its peak,<br />
according to Robert F. McGivern of San Diego State University.<br />
Response speed improves gradually after puberty and stabilizes at around<br />
age 15, a <strong>time</strong> when substantial neural pruning and myelin expansion in <strong>the</strong><br />
frontal lobes have already occurred, McGivern and his colleagues reported in<br />
2002.<br />
The researchers had studied 246 youngsters, ages 10 to 17, and 49 young<br />
<strong>adult</strong>s, ages 18 to 22. In one trial, participants saw a series of faces with<br />
various posed expressions—happy, angry, sad, or neutral—after being told to<br />
answer "yes" if <strong>the</strong>y saw a happy face and "no" <strong>for</strong> all o<strong>the</strong>rs. Each face<br />
appeared <strong>for</strong> only a fraction of a second.<br />
The participants <strong>the</strong>n completed three additional trials in which <strong>the</strong>y were told<br />
to answer "yes" <strong>for</strong> angry, sad, or neutral faces.<br />
Girls responded to <strong>the</strong>se problems more slowly at ages 11 and 12 than <strong>the</strong>y<br />
did at age 10, while boys took longer to answer at age 12 than <strong>the</strong>y did at<br />
ages 11 or 10. These declines closely corresponded to puberty's onset in<br />
each sex, McGivern says.<br />
Cycles of brain growth in boys and girls, which are <strong>time</strong>d differently during<br />
adolescence, some<strong>time</strong>s aid and some<strong>time</strong>s hinder mental dexterity in<br />
detecting various emotions, in McGivern's view.<br />
Risky business<br />
Scientists are also beginning to probe <strong>the</strong> brain's contributions to teenagers'<br />
penchant <strong>for</strong> risky and impulsive behaviors, such as experimenting with illicit<br />
drugs. Preliminary data indicate that, while playing a simple game to win<br />
monetary prizes, adolescents exhibit weaker activity than young <strong>adult</strong>s do in a<br />
brain region that scientists consider to be crucial <strong>for</strong> motivating ef<strong>for</strong>ts to<br />
obtain rewards or attain goals.<br />
A team led by James M. Bjork of <strong>the</strong> National Institute on Alcohol Abuse and<br />
Alcoholism in Be<strong>the</strong>sda, Md., used fMRI to scan <strong>the</strong> brains of 24 people, half<br />
between ages 12 and 17 and <strong>the</strong> rest between 22 and 28. Brain<br />
measurements were taken as <strong>the</strong> participants decided whe<strong>the</strong>r to press a<br />
button upon seeing various visual cues, only one of which <strong>the</strong>y had been told<br />
to respond to. On some trials, correct answers yielded prizes of 20 cents, 1<br />
dollar, or 5 dollars. On o<strong>the</strong>rs, correct answers prevented losses of those<br />
amounts.<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
The prospect of gaining or losing money elicited many common responses in<br />
<strong>the</strong> brains of teens and young <strong>adult</strong>s, <strong>the</strong> scientists reported in <strong>the</strong> Feb. 25<br />
Journal of Neuroscience. However, on potential moneymaking trials, teens<br />
displayed unusually weak activity in <strong>the</strong> right ventral striatum, a structure at<br />
<strong>the</strong> brain's base that's been implicated in fueling <strong>the</strong> motivation to acquire<br />
rewards.<br />
This finding is consistent with <strong>the</strong> <strong>the</strong>ory that <strong>the</strong> amount of stimulation that's<br />
enough to give <strong>adult</strong>s a motivational boost is insufficient to arouse teens. To<br />
get <strong>the</strong> same rewarding feeling, teens may seek <strong>the</strong> added lift that comes<br />
from risky behaviors. Bjork and his coworkers plan to conduct larger fMRI<br />
studies of teen motivation that include youngsters prone to delinquency and<br />
drug abuse.<br />
There's still a long way to go in untangling how brain development influences<br />
what teens do and why <strong>the</strong>y do it, remarks Jay N. Giedd of <strong>the</strong> National<br />
Institute of Mental Health in Be<strong>the</strong>sda. Courts and legislatures grappling with<br />
<strong>the</strong> juvenile death penalty none<strong>the</strong>less need to consider <strong>the</strong> brain's unfinished<br />
status during adolescence, especially in <strong>the</strong> frontal lobes, according to Giedd,<br />
a pioneer in research on brain development.<br />
Adds neuroscientist Bruce McEwen of Rockefeller University in New York<br />
City, "There's enough known about brain development to call <strong>for</strong> serious<br />
discussions between scientists and <strong>the</strong> legal community."<br />
Immature data<br />
UCLA's Elizabeth Sowell, ano<strong>the</strong>r prominent brain-development researcher,<br />
takes a dim view of <strong>the</strong> movement to apply neuroscience to <strong>the</strong> law. Delayed<br />
frontal-lobe maturation may eventually be shown to affect teenagers' capacity<br />
to make long-term plans and control <strong>the</strong>ir impulses, she says, but no current<br />
research connects specific brain traits of typical teenagers to any mental or<br />
behavioral problems.<br />
"The scientific data aren't ready to be used by <strong>the</strong> judicial system," she<br />
remarks. "The hardest thing [<strong>for</strong> neuroscientists to do] is to bring brain<br />
research into real-life contexts."<br />
The ambiguities of science don't mix with social and political causes, contends<br />
neuroscientist Bradley S. Peterson of <strong>the</strong> Columbia College of Physicians and<br />
Surgeons in New York City. For instance, it's impossible to say at what age<br />
teenagers become biologically mature because <strong>the</strong> brain continues to develop<br />
in crucial ways well into <strong>adult</strong>hood, he argues.<br />
A team led by Sowell and Peterson used an MRI scanner to probe <strong>the</strong> volume<br />
of white and gray matter throughout <strong>the</strong> brains of 176 healthy volunteers,<br />
ages 7 to 87. The researchers reported in <strong>the</strong> March 2003 Nature<br />
Neuroscience that myelin <strong>for</strong>mation—measured by <strong>the</strong> total volume of white<br />
matter in <strong>the</strong> entire brain—doesn't reach its peak until around age 45.<br />
Although gray matter volume generally declines beginning around age 7, it<br />
steadily increases until age 30 in a temporal-lobe region associated with<br />
language comprehension.<br />
Such findings underscore <strong>the</strong> lack of any sharp transition in brain<br />
development that signals maturity, according to neuroscientist William T.<br />
Greenough of <strong>the</strong> University of Illinois at Urbana-Champaign. Definitions of<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
<strong>adult</strong>hood change depending on social circumstances, Greenough points out.<br />
Only 200 years ago, Western societies regarded 16-year-olds as <strong>adult</strong>s.<br />
"Brain science offers no simple take-home message about adolescents," says<br />
B.J. Casey of Cornell University's Weill Medical College in New York City. "It's<br />
amazing how little we know about <strong>the</strong> developing brain."<br />
Brain-scanning techniques, including <strong>the</strong> popular fMRI, remain a "crude level<br />
of analysis," Casey notes. At best, blood-flow measurements indirectly tap<br />
into brain-cell activity as people per<strong>for</strong>m a task, such as identifying emotions<br />
in posed faces, that may superficially simulate a real-world endeavor. What's<br />
more, many critical brain-cell responses are too fast <strong>for</strong> MRI to track.<br />
Brain data, particularly those on delayed frontal-lobe growth in adolescents,<br />
also need to be put in a cultural and historical perspective, Harvard's Kagan<br />
asserts. Frontal-lobe development presumably proceeds at roughly <strong>the</strong> same<br />
pace in teenagers everywhere. Yet current rates of teen violence and murder<br />
vary from remarkably low to alarmingly high from country to country, he notes.<br />
"Something about cultural context must be critical here," Kagan says. "Under<br />
<strong>the</strong> right conditions, 15-year-olds can control <strong>the</strong>ir impulses without having<br />
fully developed frontal lobes."<br />
If incomplete brains automatically reduce adolescents' capacity to restrain<br />
<strong>the</strong>ir darker urges, "we should be having Columbine incidents every week," he<br />
adds.<br />
Several research teams have now undertaken <strong>the</strong> difficult task of searching<br />
<strong>for</strong> links between specific traits of teens' brains and <strong>the</strong>ir real-life decisions<br />
and behaviors, says psychiatrist Ronald Dahl of <strong>the</strong> University of Pittsburgh<br />
Medical Center. "Brain data are eventually going to support reduced legal<br />
culpability <strong>for</strong> adolescents," Dahl predicts "but we're not quite <strong>the</strong>re yet."<br />
It remains to be seen where <strong>the</strong> Supreme Court is.<br />
Letters:<br />
I am not an advocate of capital punishment, but I wonder whe<strong>the</strong>r <strong>the</strong><br />
people and organizations who are so anxious to use findings on brain<br />
maturity to raise <strong>the</strong> age of capitol punishment have considered <strong>the</strong><br />
consequences of winning <strong>the</strong>ir case. One might argue on <strong>the</strong> same basis<br />
that anyone who has not yet reached <strong>the</strong> "age of brain maturity" should<br />
not be allowed to make potentially life-altering decisions. Should such<br />
people be permitted to volunteer <strong>for</strong> <strong>the</strong> armed services Should <strong>the</strong>y be<br />
denied access to any <strong>for</strong>m of weapon Should <strong>the</strong>y be permitted to<br />
participate in any high-risk sport Should <strong>the</strong>y be allowed to operate cars<br />
and o<strong>the</strong>r vehicles if <strong>the</strong>ir immature brains could lead <strong>the</strong>m to make bad,<br />
or even lethal, driving decisions Would it not be possible to argue that<br />
such measures would protect society at large<br />
Lance C. Labun<br />
Tempe, Ariz.<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
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References:<br />
Baird, A.A., et al. 1999. Functional magnetic resonance imaging of facial<br />
affect recognition in children and adolescents. Journal of <strong>the</strong> American<br />
Academy of Child and Adolescent Psychiatry 38(February):195.<br />
Bjork, J.M., et al. 2004. Incentive-elicited brain activation in adolescents:<br />
Similarities and differences from young <strong>adult</strong>s. Journal of Neuroscience 24<br />
(Feb. 25):1793-1802. Abstract available at http://www.jneurosci.org/cgi/<br />
content/abstract/24/8/1793.<br />
McGivern, R.F., et al. 2002. Cognitive efficiency on a match to sample<br />
task decreases at <strong>the</strong> onset of puberty in children. Brain and Cognition<br />
50:73-89.<br />
Sowell, E.R., B.S. Peterson, et al. 2003. Mapping cortical change across<br />
<strong>the</strong> human life span. Nature Neuroscience 6(March):309-315. Abstract<br />
available at http://dx.doi.org/10.1038/nn1008.<br />
Sources:<br />
Abigail Baird<br />
Department of Psychological and Brain Science<br />
Dartmouth College<br />
6207 Moore Hall<br />
Hanover, NH 03755<br />
James M. Bjork<br />
National Institute on Alcohol Abuse and Alcoholism<br />
National Institutes of Health<br />
10 Center Drive, Room 3C-103<br />
Be<strong>the</strong>sda, MD 20892<br />
Ronald E. Dahl<br />
Western Psychiatric Institute and Clinic<br />
Department of Psychiatry<br />
Thomas Detre Hall<br />
University of Pittsburgh<br />
3811 O'Hara Street<br />
Pittsburgh, PA 15213<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
David G. Fassler<br />
University of Vermont<br />
Department of Psychiatry<br />
c/o Otter Creek Association<br />
86 Lake Street<br />
Burlington, VT 05401<br />
Jay N. Giedd<br />
Building 10, Room 4C110<br />
National Institutes of Health<br />
National Institute of Mental Health<br />
Magnuson CC<br />
Be<strong>the</strong>sda, MD 20892<br />
William T. Greenough<br />
University of Illinois, Urbana-Champaign<br />
2325 Beckman Institute<br />
405 N. Mat<strong>the</strong>ws Avenue<br />
Urbana, IL 61801<br />
Stephen K. Harper<br />
University of Miami<br />
School of Law<br />
1311 Miller Drive<br />
Coral Gables, FL 33146<br />
Jerome Kagan<br />
Harvard University<br />
Department of Psychology<br />
1514 WM James Hall<br />
Cambridge, MA 02138<br />
Robert F. McGivern<br />
San Diego State University<br />
6330 Alvarado Ct, 207<br />
San Diego, CA 92120<br />
J. Anthony Movshon<br />
New York University<br />
Center <strong>for</strong> Neural Science<br />
4 Washington Place, Room 809<br />
New York, NY 10003<br />
Bradley S. Peterson<br />
Columbia College of Physicians & Surgeons<br />
Department of Psychiatry<br />
New York State Psychiatric Institute<br />
New York, NY 10032<br />
Elizabeth R. Sowell<br />
University of Cali<strong>for</strong>nia, Los Angeles<br />
Laboratory of Neuroimaging<br />
Department of Neurology<br />
710 Westwood Plaza, Room 4-238<br />
Los Angeles, CA 90024-1769<br />
Deborah Yurgelun-Todd<br />
McLean Hospital<br />
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Teen Brains on Trial: Science News Online, May 8, 2004<br />
P.O. Box 9106<br />
Belmont, MA 02478<br />
From Science News, Vol. 165, No. 19, May 8, 2004, p. 299.<br />
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