S1 (FriAM 1-65) - The Psychonomic Society

Posters 3044–3050 Friday Evening
instructions on sequential task preparation in task switching. To this
end, a three-task cuing paradigm was devised in which both switches
and repetitions were predictable. Experiment 1 manipulated predictability
(predictable vs. random) while preparation time (i.e.,
cue–stimulus interval, CSI) remained constantly short. Experiment 2
manipulated CSI in predictable sequential transitions. Both experiments
showed clear instruction effects, but these were restricted to
task repetitions, for which sequential predictability determined the
identity of the upcoming task. Predictability effects were small in task
switches, and they were not modulated by instruction, suggesting that
preparation is mainly task-specific rather than switch-specific. Together,
the experiments suggest that intentional processes contribute
to predictability benefits in task repetitions, probably by enhancing
the monitoring of sequential task transitions in working memory in
order to maintain task activation in task repetitions.
(3044)
Advance Reconfiguration Prior to Probe Onsets in Voluntary Task
Switching. BAPTIST LIEFOOGHE, EVELYNE LAGROU, FREDER-
ICK VERBRUGGEN, ANDRÉ VANDIERENDONCK, & ROBERT
HARTSUIKER, Ghent University (sponsored by Robert Hartsuiker)—
In the voluntary task-switching paradigm, Arrington and Logan (2005)
introduced a procedure in which participants selected a task when a
probe was presented, prior to the stimulus onset. They observed preparation
effects prior to stimulus onsets which suggest the presence of advance
task-set reconfiguration. The present study investigated when participants
started such reconfiguration by focusing on preparation effects
prior to probe onsets. More specifically, we tested whether participants
engaged advance reconfiguration when sufficient time was provided between
the response on a previous trial and the probe onset. Preparation
effects prior to probe onsets were observed for predictable probe onsets
(Experiment 2) but not for unpredictable probe onsets (Experiment 1).
These findings are consistent with the hypothesis that advance reconfiguration
prior to probe onsets is possible, albeit under certain conditions.
We suggest that advance reconfiguration prior to probe onsets does
not occur with unpredictable probe onsets as a result of the high demands
associated with advance reconfiguration under such conditions.
(3045)
Stimulus–Task Associations and Response Competition in Task
Switching. SUSAN LAGRONE & DANIEL H. SPIELER, Georgia
Institute of Technology—Task switch costs may be influenced by prior
stimulus–task associations (Rogers & Monsell, 1995). Using pictureword
stimuli, we replicated the finding that prior stimulus–task associations
influence switch costs (Waszak, Hommel, & Allport, 2003).
In a second experiment, we used a task that did not have the significant
response competition component present in processing pictureword
stimuli. We manipulated prior stimulus–task associations by having
participants make two possible semantic judgments (animacy and
size) on word stimuli. In this case, stimulus–task associations had no
influence on task switch costs. These results suggest that prior stimulus–task
associations may exert an influence on task switching performance
primarily in situations with significant response competition.
(3046)
Task Preparation and Transition Frequency: Characterizing
Preparation Through Previous Trial Control Demands. ANITA D.
BARBER & WALTER S. SCHNEIDER, University of Pittsburgh and
Center for the Neural Basis of Cognition (sponsored by Christian
Schunn)—Recent studies have found that the preparatory switch cost
is reduced when switch frequency is high relative to repeat frequency
(Logan & Schneider, 2006; Monsell & Mizon, 2006). However, other
studies have found that switch frequency does not affect the switch
cost, but instead causes a general increase in RT on all trials
(Reynolds, Brown, & Braver, in press; Schneider & Logan, 2007).
Presently, two experiments manipulated switch frequency to determine
whether switch preparation is selectively influenced or whether
general task preparation is affected. Task frequency was also manip-
93
ulated to examine whether previous trial switching affects frequent
and infrequent trials similarly. It was found that a previous trial task
switch increased RT for the current trial regardless of whether the current
trial was a switch or repeat. For infrequent trials, the previous
switch type had little effect on task preparation. A model of switch frequency
effects on task preparation is presented.
(3047)
Exploring the Characteristics of Tool-Associated Transformation
Rules in a Tool-Switching Paradigm. MIRIAM LEPPER, CRISTINA
MASSEN, & WOLFGANG PRINZ, Max Planck Institute for Human
Cognitive and Brain Sciences—In tool use, we have to realize the toolspecific
transformation rule that transforms our bodily movement (action)
into the desired tool movement (effect). Our participants had to
switch between tool-use actions: They had to open or to close tools.
Depending on the tool structure, the tool-associated transformation
rule was either compatible (bodily movement = tool movement) or incompatible
(bodily movement != tool movement). For the compatible
transformation rule, we found rule priming effects that were independent
from movement repetitions/switches. For the incompatible
transformation rule, however, the benefit of rule priming was present
only for movement repetitions. We argue that the compatible transformation
rule is represented as a default set of natural action–effect
associations. Priming of this default set leads to a benefit on action.
For the incompatible transformation rule, action–effect associations
are artificial and have to be computed anew in each trial. Therefore,
only priming of concrete action–effect associations is beneficial.
• SELECTIVE ATTENTION •
(3048)
When You’re Not Sure What You’re Looking For: Visual Search
Under Conditions of Uncertainty. MONICA S. CASTELHANO,
Queen’s University, & ALEXANDER POLLATSEK & KYLE R. CAVE,
University of Massachusetts, Amherst—What if you’re looking for
something, but don’t know what it looks like? Participants search for
an object when shown either the target’s picture or name (basic-level
category). Targets were either a typical or an atypical category member.
There was no typicality effect when searching for a picture target.
For named targets, there was a modest gain in the latency to fixate
the target for typical items. However, the bulk of the typicality
effect for named targets was in “verification time”: After initially fixating
the target, there were more fixations to distractors and longer
gaze durations on atypical target items. Thus, most of the effect of object
typicality on the search is in verifying that the target matches the
category label, not in the original selection of target candidates.
(3049)
Shifts of Attention Between Two Objects During Spatial Relationship
Judgments. STEVEN L. FRANCONERI, Northwestern University—
The ability to judge spatial relationships among objects in the world
is a fundamental part of visual processing. Although these judgments
can be attentionally demanding, as demonstrated by inefficient visual
search for targets defined by a spatial relationship, there is little evidence
of why. We asked participants to report whether displays contained
a red square on the left of fixation and a green square on the
right, or the opposite arrangement. Using ERP, we measured a high
temporal resolution trace of horizontal shifts of attention, by examining
the difference over time between left and right electrode sites over
visual cortex. Each participant shifted attention between objects starting
150 msec after display onset, and the order and timing of shifts
differed among subjects. Despite the feeling that we apprehend spatial
relationships between two objects by attending to both at once,
these results suggest that these judgments have a serial component.
(3050)
Asymmetric Flanker Compatibility Effects Become Symmetric
Across Space. JEFFREY R. W. MOUNTS, SUNY, Geneseo, JASON S.