S1 (FriAM 1-65) - The Psychonomic Society

Thursday Evening Posters 1103–1109
but by altering the implicit discounting of evidence which remains important
regardless of prime diagnosticity.
(1103)
Perception of Affordances for Standing Depends on Height of
Center of Mass. TONY REGIA-CORTE & JEFFREY B. WAGMAN,
Illinois State University—We investigated whether perceiver-actors
are sensitive to how changes in the height of their center of mass influence
their ability to stand on an inclined surface. Participants adjusted
the angle of a surface until they felt that it was just barely possible
for them to stand on that surface. Weights were attached to a
backpack apparatus worn by participants so as to change the location
of the participant’s center of mass. Participants performed this task in
each of three mass-placement conditions—raised mass, centered
mass, and no mass. In addition, participants performed the task in
each of two perceptual modalities—they perceived the surface by
viewing it and by probing it with a handheld rod (while blindfolded).
Perception of affordances for standing on the inclined surface depended
on the height of the center of mass but did not depend on the
perceptual modality by which the surface was perceived.
(1104)
Representing the Orientation of Objects: Evidence From Adults’
Error Patterns. EMMA GREGORY & MICHAEL MCCLOSKEY,
Johns Hopkins University—Representing the orientation of objects in
the visual field is essential for interacting with the world, yet little research
has explored how the visual system represents object orientation.
We present a theoretical framework conceiving of orientation as
a relationship between reference frames. According to the theory, orientation
representations map an object-centered reference frame onto
a reference frame external to the object, with this mapping specified
by several independent elements. The theory makes predictions about
the error types that should occur in perceiving and remembering object
orientation. In several experiments testing these predictions, pictures
of objects were presented briefly, and participants reported the
orientations of the objects. We argue that the observed errors support
the two key assumptions of the theory: (1) Orientation representations
have a componential structure, and (2) object-centered reference
frames play a central role in orientation representation. We also argue
that alternative hypotheses cannot account for our results.
(1105)
Exaggerated Leftward Bias for Faces in Mirror-View. YAMAYA
SOSA-MACHADO & MARK E. MCCOURT, North Dakota State University
(sponsored by Mark E. McCourt)—Healthy dextral subjects
(N = 49) performed tachistoscopic line-bisection (LB) and free-viewing
chimeric-face (CF) emotional valence discrimination tasks when
stimuli were viewed either directly or in obvious mirror reflection.
Leftward biases typify performance of normal observers in both LB
and CF tasks. We hypothesized that leftward bias would be reduced
for stimuli viewed in mirrors. Single-sample t tests showed a significant
egocentric leftward bias for both tasks in both direct-view and
mirror-view conditions ( p � .01). For LB, leftward bias did not differ
in direct- versus mirror-viewing ( p = .315). Leftward bias in the
CF task was significantly greater ( p = .017) in mirror- versus directview
conditions (71.9% and 64.5%, respectively). The results indicate
that mirror viewing selectively exaggerates the egocentric leftward
bias associated with processing happy facial expressions.
(1106)
What’s in a Name? Species of Redundancy in Visual Target Detection.
BOAZ M. BEN-DAVID, University of Toronto, Mississauga,
& DANIEL ALGOM, Tel Aviv University (sponsored by Daniel
Algom)—We report a series of investigations into the effects of common
names, physical similarity, and physical identity on signal detection
time and capacity of the system processing the signals. Examined
are target–distractor (single target), target–target (redundant
targets), and distractor–distractor (no targets) displays in a redundant
66
signals design. Detection is impeded when the to-be-ignored distractor
shares name or a physical feature with the target, but redundancy
gain is larger and signal processing is of increased capacity
under such conditions. Redundant targets coactivate detection in situations
in which several different target-pairs exist; otherwise, there
is a parallel race. Finally, physically identical targets and distractors
precipitate the fastest reactions in all conditions. The enormous sensitivity
of the human detector to subtle features of the situation is uncovered,
and the guiding principles for a truly encompassing model
are outlined.
• WORKING MEMORY •
(1107)
Working Memory Training in Older Adults. BARBARA CARRETTI,
ERIKA BORELLA, CESARE CORNOLDI, & ROSSANA DE BENI,
University of Padua (sponsored by Cesare Cornoldi)—It is well assessed
that working memory (WM) has a limited capacity; nonetheless,
few studies have investigated how this limitation is affected by
practice and learning. Recently, some evidences have been collected
about the possibility to enhance WM performance, but only in young
adults. Across two studies, we examined whether two different memory
trainings can improve WM performance in older adults. In a first
experiment, participants were instructed to use a typical long-term
memory strategy (mental imagery) during an immediate recall task,
and the benefit of the use of this strategy on the performance in a WM
task was assessed. In a second experiment, participants were trained
with adaptive and demanding WM tasks to increase their WM performance.
Both studies indicated a significant improvement in WM
performance of the older experimental group in comparison with the
older control group. The results will be discussed in term of cognitive
transfer effects.
(1108)
A Deficit in Immediate Recall of Language in Older Adults.
AMANDA L. GILCHRIST, NELSON COWAN, & MOSHE NAVEH-
BENJAMIN, University of Missouri—We ask why older adults have
poorer immediate recall of language than do young adults. One hypothesis
is that older adults recall fewer units of information (chunks)
and another is that they are poorer at binding related words together
to form multiword chunks. These hypotheses were examined using 4
types of spoken materials for free recall: 4 short, simple sentences; 8
such sentences; 4 compound sentences, each comprising two of the
shorter sentences in a meaningful combination; and shuffled sentences.
By varying the length and number of separate units per trial,
we could determine how chunk formation helped recall. We classified
series of words recalled in the presented order without pause as coherent
chunks. Older adults recalled fewer chunks than did young
adults, with only small age differences in chunk size. However, older
adults used a different strategy that worked well for 4 short sentences
but was less successful for longer materials.
(1109)
Does Differential Strategy Use Account for Age-Related Differences
in Working Memory Performance? HEATHER ROTH & JOHN
DUNLOSKY, Kent State University, & CHRISTOPHER HERTZOG,
Georgia Institute of Technology—In two experiments, we evaluated
whether strategy use accounts for age-related differences in performance
on working memory span tasks. In both experiments, participants
completed the reading span task and the operation span task and
reported strategies used for each set of to-be-remembered items. Age
deficits in overall span performance were observed on both tasks, and
individuals performed significantly better on trials for which they reported
using effective strategies. Despite the overall age difference in
span performance, young and older adults reported using the same
proportion of effective strategies on both tasks. Thus, although strategy
use does contribute to performance on span tasks, it does not account
for the observed age-related deficit.