Abstracts 2005 - The Psychonomic Society

Papers 214–220 Saturday Afternoon
tent “cold” list, a “woman” set of prime and target lists, and a “terrorist”
set of lists. There were three opportunities to recall all target
lists. Results showed no reliable difference between false reports of
“cold” and those of “African American,” but both significantly exceeded
false reports related to “woman” and “terrorist,” which did not
differ from each other ( ps = .000 to .008).
2:30–2:45 (214)
False Memory for Emotionally Charged Words. PETER B. WALKER,
PAUL A. HOUCK, & W. TRAMMELL NEILL, SUNY, Albany (read
by W. Trammell Neill)—Participants studied lists of words that were
phonologically similar to emotionally charged words (e.g., rape) or
neutral words (e.g., park). The critical word was included in some
studied lists, which allowed measurement of hit rates as well as false
alarms on a subsequent recognition memory test. As previously found
by Pesta, Murphy, and Sanders (2001), false alarms were increased for
list-related charged words relative to charged words related to unstudied
lists. However, hit rates for charged words were also very high,
and d′ was much higher for charged words than for both neutral critical
words and list words that were phonologically similar to charged
words. The results suggest limitations on generalizing from the DRM
list procedure to putatively false memories for emotional and traumatic
events.
2:50–3:05 (215)
The Effect of Strength on Source Memory Judgments of True and
False Memories. IRA E. HYMAN & EDWIN ANDERSON, Western
Washington University—True and false memories are predicted to differ
in terms of source memory. We investigated the effect of strength
on recognition and source judgments using two different methodologies:
Deese/Roediger–McDermott word lists and Bransford and Franks sentences.
We varied strength by presenting different numbers of items
related to each topic during encoding. Strength affected recognition
rates of old and new words and sentences but had little effect on source
judgments. Instead, participants made source judgments based on relatedness
to the topics of the studied lists. Source memory does not
differentiate true and false memories and appears to be constructed.
3:10–3:25 (216)
Recollection Rejection of Constructed False Memories. C. J. BRAIN-
ERD, V. F. REYNA, & S. ESTRADA, Cornell University—Recollection
rejection is a verbatim operation of key forensic interest because it
generates principled suppression of false-memory responses by neutralizing
the familiarity of new events that preserve the meaning of experience.
Mathematical models that partition memory processes for
word lists were used to measure recollection rejection of false memories
in Bransford–Franks narratives. Parameter estimates showed that
recollection rejection suppressed those false memories 50% of the
time, even when distractors’ surface structure and meaning were almost
the same as the targets’. Manipulations that strengthen verbatim
memory (e.g., target repetition, target presentation order, repeated
testing) improved recollection rejection. Surprisingly high levels of
recollection rejection were preserved intact over a 1-week interval in
conditions that inoculated verbatim traces against disintegration. Although
our findings violate constructivist theories of narrative memory,
they are explained by dual-process theories that stress the opposing
effects of verbatim and gist traces on false memory.
3:30–3:45 (217)
False Retrieval of Text. MURRAY SINGER, University of Manitoba,
& GILBERT REMILLARD, Morehead State University—Our research
evaluated the hypothesis that text inference retrieval receives support
from a process of phantom recollection (Brainerd et al., JEP:LMC,
2001) plus recollection and familiarity. We used Brainerd et al.’s conjoint
recognition procedure: Three groups were respectively instructed
to accept test probes if (1) they recognized them, (2) the probe
matched the gist of an antecedent message, and (3) the probe was implied,
but not stated, in a message. A 3-process phantom recognition
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model was compared with two 2-process models: a traditional model
and one that blended process dissociation and phantom recognition.
For 0- versus 2-day delayed text retrieval, only the 3-process model
satisfactorily fit the data, and phantom recollection was invariant with
delay. In a shallow-encoding experiment, however, phantom recognition
was negligible, and the 2-process models achieved satisfactory
fits. These results are consistent with a phantom-recognition process
that reflects robust gist-based representations.
Motor Control
Dominion Ballroom, Saturday Afternoon, 1:30–3:50
Chaired by Jonathan Vaughan, Hamilton College
1:30–1:45 (218)
Planning Trajectories in 3-D Space on the Basis of Three Postures.
JONATHAN VAUGHAN, Hamilton College, MARY KLEIN BRETE-
LER, Radboud University Nijmegen, DAVID A. ROSENBAUM, Pennsylvania
State University, STEVEN JAX, Moss Rehabilitation Research
Institute, & KIMBERLY LANTZ & ARAM KUDURSHIAN,
Hamilton College—To move an arm, one must plan both a target posture
and the movement trajectory to it. Forearm movements around
obstacles in 2-D space have been modeled by superimposing a symmetric
reversible movement to a “bounce” posture on the direct movement
from start to target posture. Modeling 3-D movements is more
challenging because of the noncommutativity of successive rotations
about different joint axes. We now extend the obstacle-avoidance algorithm,
based on three postures, to trajectories in 3-D. Eight seated
subjects touched a handheld tool to a sequence of targets, sometimes
circumventing an obstacle. Trajectories (with six postural degrees of
freedom) were modeled using the observed start and target postures
and one intermediate bounce posture. Circuitous 3-D trajectories were
synthesized by superimposing a direct movement to the target (using
single-axis joint rotations) and a reversible movement to a bounce
posture. The results support the role of postural representations in
motor planning.
1:50–2:05 (219)
Looking Into the Future: How We Grasp Objects Reflects Anticipation
of Future Positions. DAVID A. ROSENBAUM & RAJAL G.
COHEN, Pennsylvania State University—The farther into the future
one looks, the less sure one can be about the usefulness of one’s plans.
On the other hand, immediately forthcoming events may be anticipated
with great precision. One domain where such near-term anticipation
can be studied is motor control, where the way one behaves at
some point in time may reflect the nature of the plan for the behavior
to follow. We illustrate this approach in a series of studies on object
manipulation. Our subjects reached for an object, knowing they
would transport it to other locations. How they took hold of the object
reflected considerable sensitivity to future states. The results indicate
that behavioral methods are important for studying motor planning
and that the study of motor planning may reveal much about
cognition.
2:10–2:25 (220)
Fitts’s Law in Actual and Imagined Action: A Closer Look.
SUZANNE M. GRILLI & ANDREW B. SLIFKIN, Cleveland State
University (read by Andrew B. Slifkin)—A large literature suggests
substantial overlap of the processes involved in actual and imagined
action. For example, in a Fitts aiming paradigm, actual and imagined
movement time (MT) was essentially identical at common levels of
the index of difficulty (ID) (see, e.g., Sirigu et al., 1996). Here, we
extend that research by examining performance over a broadened
range of target amplitudes (A) and widths (W): ID ranged from 1.00
to 5.00 bits, and W ranged from 0.13 to 2.16 cm within each ID level.
MT always increased with ID, and within each ID level MT was constant
across the larger values of W. Those results confirm Fitts’s law.
However, MT tended to lengthen with further reductions in W. This