Abstracts 2005 - The Psychonomic Society

Thursday Evening Posters 1078–1084
ticipants performed a flanker response-competition task including 1, 3,
or 6 items in the target display while holding 0, 5 sequentially ordered,
or 5 randomly ordered digits in working memory. In a replication of previous
work by Lavie and others, increased perceptual load produced increased
interference in the flanker task. However, the effects of working
memory load did not appear to be additive or independent.
(1078)
Task Reconfiguration and Carryover Effects of Switching Between
Stimulus Sets. SHULAN HSIEH & POYUI CHEN, National Chung
Cheng University—The aim of this study was to extend our previous
studies of task switching with response-set paradigms. In this study,
we measured both event-related potentials and lateralized readiness
potentials. In addition, we have used a stimulus-set switching rather
than a response-set switching paradigm. The results showed that task
switching may involve both reconfiguration and carryover effects, but
they may take place at different stages in time. Task reconfiguration
specific to task switching may take place before the onset of a
switched task, as reflected on a difference wave between repeat and
switch trials during the response–stimulus intervals; the carryover effect
remains, however, regardless of preparation, and results in prolongation
of response selection processing, as reflected by the stimuluslocked
lateralized readiness potentials.
(1079)
Effects of Oculomotor Inhibition Across the Life Span. BETTINA
OLK, International University Bremen, & ALAN F. KINGSTONE,
University of British Columbia—We investigated the effects of oculomotor
inhibition on saccadic reaction times (SRT) of pro- and antisaccades,
on saccade direction errors, and on the ability to maintain
fixation. The degree to which inhibition was placed on the oculomotor
system was varied systematically between conditions. In a noinhibition
condition, prosaccades to a target were required on every
trial. In low–high inhibition conditions, prosaccades and trials on
which fixation was maintained (10%–50% of trials) were randomized.
In low–high inhibition/volitional saccade conditions, an eye movement
was required on every trial, since prosaccade and antisaccade trials
(10%–50% of trials) were randomized. With increasing inhibition,
SRT of prosaccades gradually increased, and the ability to maintain
fixation improved. SRT of antisaccades decreased, as did the amount
of saccade direction errors, reflecting sensitivity of SRT and saccade
errors to oculomotor inhibition. Elderly participants initiated saccades
more slowly and showed more saccade direction errors on antisaccade
trials than did younger participants.
(1080)
Electrophysiological Activity Elicited by Attention-Directing Cues:
Preparatory Visual Activity or Mechanism for Shifting Attention?
JESSICA J. GREEN, JOHN J. MCDONALD, & DANIEL J. WEEKS,
Simon Fraser University—When a central symbolic cue is used to direct
attention to a lateralized location prior to a target, the cue-elicited
event-related potential (ERP) is more positive over the posterior scalp
on the side contralateral to the to-be-attended location. This enhanced
contralateral ERP may reflect preparatory activity in visual cortex or
activity in parietal cortex related to the shifting of attention. To better
isolate the cue-elicited activity of interest, we compared leftwardand
rightward-directing cues with a neutral cue (Experiment 1). We
also sought to determine whether the enhanced contralateral ERP reflects
activity in a retinotopically mapped visual area by comparing
the cue-elicited ERPs for shifts of attention to the upper and lower visual
fields (Experiment 2). The results indicated that the enhanced
contralateral ERP arises primarily in occipital cortex, thereby supporting
the notion that it reflects preparatory modulation of neural activity
prior to the appearance of a target.
(1081)
Effects of Background Music on Spatial and Linguistic Processing.
LESLIE A. ANGEL, DONALD J. POLZELLA, & GREG C. ELVERS,
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University of Dayton—College students were trained according to one
of two standardized task protocols: spatial (mental rotation) or linguistic
(letter classification). Testing consisted of multiple randomized
trials with and without background music (classical piano) at two
levels of task difficulty. Raw data for both tasks were response time
and accuracy. Background music increased the speed of spatial processing
at both difficulty levels, whereas accuracy of processing remained
unaffected. In contrast, background music increased the accuracy
of linguistic processing, whereas speed of processing remained
unaffected. These findings, integrated with those of a previous experiment
from our laboratory, suggest that (1) regardless of an individual’s
predilection, background music can affect aspects of human
performance, and (2) the specific effects, whether enhancing or disrupting,
appear to reflect the similarity between the task demands and
certain objective characteristics of the background music.
(1082)
Effects of Tempo on Rhythmicity of Auditory Attention. W. J.
DOWLING, University of Texas, Dallas, & BARBARA TILLMANN,
CNRS–UMR 5020 Lyon—In 2004, we reported that following a
knowledge-based cue (a melody pointing up or down in pitch, 80%
valid), the convergence of an implicit beat with cue validity led to RT
benefits for identification of targets presented after brief delays. Targets
were fast (8-Hz) or slow (3-Hz) amplitude modulation warbles,
and participants made speeded identification judgments. The tempo
of the implicit beat was 72 beats/min. In the present study, we varied
the tempo of the implicit beat between 58 and 102 beats/min. RT benefits
were strongest around 72 beats/min and disappeared gradually
as the tempo was increased. This suggests that if the cue-validity benefits
arise from the entraining of an internal oscillator by the implicit
beat in the stimulus, entrainment occurs most easily when the beat rate
is close to a “comfortable” rate for the perceiving system. Ongoing
experiments are testing slower tempi.
• TASK SWITCHING •
(1083)
Hierarchical Control of Cognitive Processes in Task Switching.
DARRYL W. SCHNEIDER & GORDON D. LOGAN, Vanderbilt University—Hierarchical
control of cognitive processes was studied by investigating
the interaction between higher level sequence processing
and lower level task processing in task switching performance. In four
experiments, subjects performed explicit, memorized task sequences
in the absence of external cues. Switch costs (differences in response
time between task switches and task repetitions) were strongly affected
by sequence initiation costs (slower performance for the first
serial position of a task sequence), to the extent that negative switch
costs were observed for some task sequences. Sequence initiation
costs were found to be sensitive to sequence complexity (as indexed
by the number of within-sequence task switches), preparation time,
and the type of sequence transition (sequence repetition or sequence
switch). These findings suggest that task performance is guided by hierarchical
control structures and that higher level sequence processing
dominates lower level task processing.
(1084)
Mapping the Time Course Function of Preparation for Predictable
and Unpredictable Task Switching Paradigms: A Meta-Analysis.
CHRISTINA V. WASYLYSHYN, MARTIN J. SLIWINSKI, & PAUL
VERHAEGHEN, Syracuse University (sponsored by Paul Verhaeghen)—
A meta-analysis of 71 studies (with 141 independent participant groups)
was conducted to estimate the time course function of preparation in
unpredictable (explicit task cuing) and predictable (alternate runs)
task switching paradigms. Latency (nonswitch RT, switch RT, and
switch costs) served as the dependent variable. Reduction of the
switch cost with advance knowledge is commonly thought to reflect
executive control processes—that is, the intentional preparation for a
task switch. A negative exponential function was modeled to describe