Abstracts 2005 - The Psychonomic Society

Posters 1085–1091 Thursday Evening
how switch costs decrease as preparation time increases in both paradigms.
Differences were found in the nature of switch costs in terms
of their rate, asymptote, and gain parameters. Mixed models of the
nonswitch and switch trial data further highlight the underlying differences
in switch costs between paradigms and lend support to the
notion that an executive control component may play a role in switch
costs for predictable but not for unpredictable task switching.
(1085)
Stimulus-Based Priming of Tasks in Task Switching. IRING KOCH
& WOLFGANG PRINZ, Max Planck Institute for Human Cognitive
and Brain Sciences, & ALAN ALLPORT, University of Oxford—Performance
costs when switching tasks are related to interference. One
determinant of task interference is whether the stimuli have previously
occurred in the context of competing tasks. To explore the role of prior
stimulus–task association in task interference, we used bivalent stimuli
but had subjects practice them with only one of two tasks (“consistent
mapping,” CM), or with both tasks (“varied mapping” of stimuli
to tasks, VM). In alphabet arithmetic tasks, we found greater
performance costs for VM than for CM stimuli. This suggests increased
interference when stimuli are associated with both tasks because
such stimuli prime the competing task. Using numerical judgment
tasks, we had subjects practice only CM stimuli and then, after
practice, reversed the consistent stimulus–task mapping. Mapping reversal
resulted in massive stimulus-priming effects. These stimuluspriming
effects were reduced by cue-based task preparation, suggesting
a precedence of cue–task over stimulus–task associations.
(1086)
Cue-Based Preparation Effects on Switch Costs and the Contents of
Task Set. AGATHA LENARTOWICZ, Princeton University, NICK
YEUNG, Carnegie Mellon University, & JONATHAN D. COHEN,
Princeton University—This study considers both whether cue-based
preparation affects switch costs and the degree to which this process
interacts with task-set contents. Schuch & Koch (2003, JEP:HPP)
have shown that in a no-go paradigm, cue-based preparation preceding
a no-go trial does not affect switch costs, thus suggesting that task
execution is the primary contributor to switch costs. In this study, we
found that both the inclusion of active no-go trials and the nature of
the task sets switched between can affect cue-based preparation. We
tested participants using two variants of a task-switching paradigm:
varying the no-go trials from active to passive, and varying the task
sets from number judgments (i.e., odd/even, greater/less than 5) to semantic
judgments (i.e., living/nonliving, large/small). Passive no-go
trials and semantic judgments resulted in larger switch costs relative
to active no-go trials and number judgments. We show that cue-based
preparation without task execution can affect the magnitude of switch
costs.
(1087)
Shift Costs and Benefits Following Errors and Error Corrections.
MARCO STEINHAUSER & RONALD HÜBNER, University of
Konstanz—When participants alternate randomly between two tasks,
performance is impaired in task shift trials relative to task repetition
trials. We hypothesized that a portion of this shift cost is caused by
the strengthening of task-related associations that took place on the
previous trial when the response was produced. Therefore, shift effects
following errors and error corrections were investigated in a series
of three experiments, in which a task-shifting paradigm with a
deadline procedure was applied. As predicted by our strengthening account,
shift benefits instead of shift costs were observed following a
specific type of error (Experiment 1). The same pattern of results occurred
when participants explicitly indicated the detection of an error
(Experiment 2). In contrast, shift costs were observed when the errors
were corrected (Experiment 3). It was concluded that the shift effects
in task-shifting are due to the strengthening of associations contingent
to the production of an overt response.
64
(1088)
Alternating Between Verbal and Spatial Memory Tasks: Costs and
Benefits. CINDY CHAMBERLAND & KATHERINE GUÉRARD,
Université Laval, FABRICE B. PARMENTIER, University of Plymouth,
ROBERT ROUSSEAU, Defence R&D Canada, & SÉBASTIEN TREM-
BLAY, Université Laval (sponsored by Robert Rousseau)—There is
ample evidence for a performance cost in alternating between tasks
(e.g., Rogers & Monsell, 1995). Most of the research has so far focused
on the impact of switching task set between identification tasks
that share the same source of information and require no memory
load. In the present study, we examined whether the task switch cost
also applies by alternating between verbal and spatial memory tasks.
The procedure required the reproduction of a sequence of stimuli: letters
for the verbal serial recall task and spatially distributed dots for
the spatial serial recall task. A recall performance cost was observed
in the spatial task, but a benefit emerged in the verbal task. This asymmetric
pattern is modulated by the memory set size and the number
of alternations. Our findings are informative with regard to the relative
contributions of interference and reconfiguration to performance.
(1089)
The Effect of the Cue-to-Stimulus Interval on Transferable Improvement
in Task Switching. MEREDITH E. MINEAR, Washington
University, & PRITI SHAH, University of Michigan, Ann Arbor—
Earlier work has demonstrated that task-switching performance can
improve with practice (Kray & Lindenberger, 2000) and that this improvement
can transfer to a new switching context (Minear et al.,
2002). In this experiment, we examined the extent to which the
amount of time given to prepare for a switch affects the training and
transfer benefits seen. We manipulated the cue-to-stimulus interval
(200 vs. 600 msec) used during training and transfer. With a short interval
(200 msec), individuals who received practice on switching
showed transferable improvement in comparison with a control group.
However, with a long interval (600 msec), in which preparation is hypothesized
to be complete, individuals who received switching practice
did not differ from a control group on a transfer task. This suggests
that transferable improvements seen after practice on switching
tasks relate to the preparatory component of switching but do not affect
the residual switch costs seen after preparation is complete.
(1090)
Effects of Bilingualism and Task Switching on Hemispheric Interaction.
SUZANNE E. WELCOME & CHRISTINE CHIARELLO, University
of California, Riverside—People perform complex tasks more
efficiently when relevant information is presented to separate hemispheres
(the across-hemisphere advantage). In this study, we investigated
whether variation in bilingual language experience affects control of
hemispheric interaction. Monolinguals, bilinguals who frequently interact
with other bilinguals, and bilinguals who primarily interact with
monolinguals performed two divided visual field tasks. Participants
received a less complex digit-matching task and a more complex addition
task with matching items shown in the same or opposite visual
fields. On half of the trials, the task was the same as the previous trial,
and on half the task switched across trials. There were no language
group differences in task-switching cost. However, language group
moderated the effect of task complexity on the across-hemisphere advantage.
Bilingualism may alter how processing is coordinated across
hemispheres.
(1091)
Sequential Dependencies in a Task-Switching Paradigm. ANDREW
P. HANLIN, SUSAN LAGRONE, & DANIEL H. SPIELER, Georgia
Institute of Technology—Traditional response time (RT) experiments
are interested primarily in variation in RT due to experimental manipulations.
Residual variability in RT is often treated as random
“noise.” Recent evidence has been presented that there are sequential
patterns in RTs over the course of an experimental session (Gilden,