S1 (FriAM 1-65) - The Psychonomic Society

Posters 3099–3105 Friday Evening
interaction condition. The finding that a couple is less likely than a
single individual to execute a task may have important theoretical and
practical implications.
• MULTISENSORY INTEGRATION •
(3099)
Intermodal Event Files: Integrating Features Across Audition, Vision,
and Action. SHARON ZMIGROD & BERNHARD HOMMEL,
Leiden University—People bind features of visual events into event
files, often together with action features. Recently, we found evidence
that auditory features (pitch, loudness, and location) are integrated the
same way. Here, we investigate whether visual and auditory features
are bound across modalities both with each other and with the action
they accompany. The results of two experiments reveal the predicted
interactions between feature-repetition effects for visual color and auditory
pitch: Repeating one feature without repeating the other
strongly impairs performance. Hence, spontaneous intermodal binding
is observed and it survives short onset asynchronies between visual
and auditory features. Feature repetition also interacts with response
repetition, suggesting stimulus–response binding. We
conclude that event files are multimodal, integrating information from
all sorts of stimulus and response dimensions.
(3100)
Time–Space Synesthesia: An Event-Related Brain Potential (ERP)
Study. URSINA TEUSCHER, DAVID BRANG, LEE EDWARDS,
MARGUERITE MCQUIRE, VILAYANUR S. RAMACHANDRAN,
& SEANA COULSON, University of California, San Diego—In one
type of synesthesia, people report that they associate time events, such
as months of the year, with specific spatial locations. The present
study investigated these synesthetic time–space associations via a
symbolic cuing paradigm. Cues consisted of arrows pointing left or
right, and the names of months that were on either the left or the right
side of the synesthete’s mental calendar. After each cue, a target stimulus
appeared in the correctly cued location 75% of the time. ERPs
were recorded from 12 time–space synesthetes and 12 age-matched
control subjects during this target detection task. Our results suggest
that, relative to controls, time–space synesthetes more effectively utilized
words referring to temporal events to direct their attention in
space. However, attentional cuing that occurred with month terms differed
from that afforded by arrows. Our data suggest that time–space
synesthesia affected stimulus categorization and response generation
rather than visual processing.
(3101)
Examining Auditory–Tactile Temporal Ventriloquism. MIRJAM
KEETELS & JEAN VROOMEN, Tilburg University (sponsored by
Jean Vroomen)—We examined whether auditory stimuli capture the
onset of tactile stimuli (i.e., auditory–tactile temporal ventriloquism).
Participants were presented two vibro-tactile stimuli with variable
temporal onset to the left and right index finger, and had to judge
which of the two came first (i.e., tactile TOJ task). To induce auditory–
tactile (AT) temporal ventriloquism, a capturing sound was, as in the
audiovisual (AV) case, presented before the first tactile stimulus and
after the second with auditory–tactile intervals of 0, 100, 200, 300, or
400 msec. JNDs were highest (i.e., lowest sensitivity) when sounds
came simultaneously with the vibrations, while there was no difference
between the 100-, 200-, 300-, and 400-msec AT intervals. The
interfering effect of simultaneous sounds became less when the distance
between the fingers increased. These results are unlike previous
reports on AV temporal ventriloquism where sensitivity improved at
100-msec intervals, and thus indicate that sound does not capture
touch.
(3102)
Sound Enhances Tactile Perception. TONY RO, JOHANAN HSU,
& NAFI YASAR, Rice University, & L. CAITLIN ELLMORE &
101
MICHAEL BEAUCHAMP, University of Texas Health Sciences Center,
Houston—Certain sounds, such as fingernails screeching down a
chalkboard, have a strong association with somatosensory percepts.
To assess the influences of audition on touch perception, four experiments
measured how task-irrelevant auditory stimuli alter detection
rates for near-threshold tactile stimuli. In Experiment 1, we showed
that a simultaneous auditory stimulus increases sensitivity, but not response
biases, to the detection of an electrical cutaneous stimulus delivered
to the hand. Experiment 2 demonstrated that this enhancement
of touch perception is spatially specific—only monaural sounds on
the same side as the touch increased detection. Experiments 3 and 4
revealed that the effects of audition on touch are also frequency dependent—only
sounds with the same frequency as the vibrotactile frequency
enhanced tactile detection. These results indicate that auditory
information influences touch perception in highly systematic ways
and suggest that similar neural mechanisms may underlie the processing
of information from these different sensory modalities.
(3103)
Novel Visual Methods Evoke Phantom Sensations and Treat Phantom
Limb Pain. DAVID H. PETERZELL, VA San Diego Healthcare
System and University of California, San Diego, ROBERTA E. CONE
& CHRISTIAN CARTER, VA San Diego Healthcare System and Alliant
International University, San Diego, ALEXANDREA HARMELL,
VA San Diego Healthcare System and University of California, San
Diego, & JUDY ORTEGA & DEBORAH VELEZ, VA San Diego
Healthcare System—It is widely reported that a simple mirror reflection
can cause phantom sensations in normal observers and reduce
phantom limb pain in amputees. We created three unusual optical conditions
that intensify these effects, and sometimes reduce phantom
pain when the simple mirror is ineffective. The first uses three vertical,
hinged mirrors oriented so that observers see side views of themselves.
The triple-reflected side view is left/right reversed. A second
uses two mirrors to provide multiple angles for lower-limb amputees.
The third (“phantom pulse”) uses a real-time video image of the observer
that flickers between a normal image and a mirror-reversed
image at rates varying from 0.5 to 2 cycles/sec (with a .2-sec delay).
For all three, movement of one limb causes phantom sensations in the
opposite limb, leading to permanent pain reduction in some amputees.
We speculate that “mirror neurons” with transient temporal properties
contribute to these profound effects.
(3104)
Synesthesia Speeds Judgments of Numerical Representation in
Simple Arithmetic Equations. THOMAS G. GHIRARDELLI,
MALLORY A. CLARK, & MERIDITH B. HURD, Goucher College—
S.E. is a 21-year-old synesthete who experiences colored images for
digits. We presented her with a computerized task requiring the classification
of simple arithmetic equations of the form A + B = C as correct
or incorrect. The digits were presented in colors that matched
S.E.’s color–digit photisms, colors that did not match her photisms,
and in black. In one experiment, we manipulated the color of the answer
and in another experiment, we manipulated the color of the two
addends. In both experiments, the remaining digits were presented in
black. S.E.’s response time was significantly faster to equations with
digits that matched her photisms, but only when the colored digits
were the answer and not when they were the addends. We conclude
that this result is due to concurrent activation of the numerical representation
from both the addends and the colored answer.
(3105)
Tactile Textures Evoke Specific Emotions: A New Form of Synesthesia.
DAVID BRANG & VILAYANUR S. RAMACHANDRAN,
University of California, San Diego (sponsored by Vilayanur S. Ramachandran)—We
studied two subjects, A.W. and H.S., in whom
highly specific textures (e.g., denim, wax, corduroy, sandpaper, silk,
etc.) evoked equally specific emotions (e.g., depression, embarrassment,
confusion, relief, and contentment), respectively. The test/retest