S1 (FriAM 1-65) - The Psychonomic Society

Posters 1042–1048 Thursday Evening
ing sequences. Interestingly, the impact of the memory task was only
present if all sequences within one experimental block had the same
type of order. Our findings are inconsistent with the notion of an automatic
activation of the “mental number line” and suggest rather that
spatial strategies might be responsible for the cognitive link between
numbers and space.
• VISUAL ATTENTION •
(1042)
Methodological Considerations and Individual Differences in Visual
Search. CHRISTOPHER K. BARRETT, UCLA, & ERIN C. ANDER-
SON, RUBEN R. ROMERO, DANIEL J. STAGGS, MOHAMMED
KORDBACHEH, & BARBARA J. CHERRY, California State University,
Fullerton—The present study used a visual search paradigm
adapted from Lupien et al. (1994) where participants were to respond
“yes” or “no” to the presence of a target (a black “x”) amid varying
distractors. Participants performed the task in two different sessions
1 to 2 weeks apart, once on a standard computer and once on a laptop
computer to determine any differences due to type of computer. Selfreport
measures of depression and stress were also completed during
session 1, since these have been reported to influence performance on
selective attention tasks. We found shorter reaction times for the laptop
versus standard computer, but no differences in accuracy. Higher
levels of stress were associated with increased errors on the visual
search task for female (but not male) participants. This was especially
true when controlling for depression. Implications of these findings
will be discussed.
(1043)
Attention Concentrates at the Centers of Stationary and Moving
Objects in Multiple-Object Scenes. CARY S. FERIA, Morehead State
University—When several moving objects are tracked, attention is
concentrated at the center of each object (Alvarez & Scholl, JEP:G,
2005; Feria & Doyle, VSS, 2006). The present study aimed to investigate
whether this center bias is caused by the tracking of motion, and
to determine what types of motion produce the bias. Observers
tracked several moving lines, while simultaneously detecting probes
appearing on the centers and ends of lines. The presence and absence
of rotational, translational, and size change components of object motion
were manipulated in a factorial design. Probe detection was more
accurate at centers than at ends of lines. This center advantage occurred
with stationary objects, and its magnitude was not affected by
different motion types. These results indicate that attention is biased
toward centers of objects in multiple-object scenes, for both stationary
and moving objects. The center bias is not caused by the tracking
of object motion.
(1044)
Nonspatial Attentional Capture Cannot Be Eliminated Under Feature
Search Mode. TOMOE INUKAI, Chukyo University, & JUN I.
KAWAHARA & TAKATSUNE KUMADA, National Institute of Advanced
Industrial Science and Technology—Performance for identifying
a visual target is impaired by a temporally preceding singleton
distractor (attentional capture). Although it is known that attentional
capture is eliminated by adopting the feature search mode, it is unclear
whether this is the case for nonspatial attentional capture. We examined
the effect of the search modes on attentional capture in spatial
and nonspatial domains. Observers’ task was to search for a target letter
defined by a specific tilt in an RSVP stream of nontarget letters
containing a color singleton distractor. The results showed that the
nonspatial singleton reduced target identification accuracy in both
search modes, while the spatially displaced singleton reduced accuracy
only when observers adopted the singleton detection mode. The
finding that the efficiency of the feature search mode for ignoring the
distractor is limited in nonspatial attentional capture suggests that different
underlying mechanisms are involved in attentional capture in
nonspatial and spatial domains.
57
(1045)
Voluntary Orienting Modulates Multiple Location Inhibition of
Return. JANICE J. SNYDER, TROY A. W. VISSER, & ROBYN
GORDON, University of British Columbia, Okanagan, & WALTER F.
BISCHOF, University of Alberta (sponsored by Walter F. Bischof)—
Inhibition of return (IOR) is thought to reflect processes that promote
efficient search by biasing attention against returning to previously inspected
locations. Consistent with this notion, IOR has been found at
up to five consecutively cued locations and is larger for difficult
search tasks. Here, we examine how the interplay of endogenous (voluntary)
and exogenous (reflexive) orienting impacts the magnitude of
IOR across multiple cued locations. An onset cue (exogenous orienting)
signalled the location of an upcoming target with high or low
probability (endogenous orienting). On half of the trials, a second cue
presented at a different location signalled that the target would instead
occur at the location of the new cue with high or low probability. Our
results provide strong support for the idea that voluntary orienting
modulates the magnitude of IOR at previously examined locations.
(1046)
It’s Alive! The Link Between Motion Onset and Behavioral Urgency.
SHAWN E. CHRIST, University of Missouri—Prior research has shown
that the introduction of motion to a previously static item (i.e., motion
onset) captures attention in an automatic stimulus-driven fashion.
It has been speculated that motion onset may be “behaviorally urgent”
in that it plays an important role in the categorization of objects as living
or nonliving, thereby helping to identify potential predators or
prey. In the present study, we sought to provide empirical support for
the notion that these cognitive phenomena are indeed linked. The results
from a series of visual search experiments are reported that suggest
an overlap in the cognitive processes underlying the categorization
of living and nonliving objects and the attentional influence of
motion onset. Findings are discussed within the context of our current
understanding of visual attention, object recognition, and their underlying
neurocognitive substrates.
(1047)
Limitations of Perceptual Segmentation on Spatial Context Effects
in Visual Search. MARKUS CONCI, LMU Munich, & ADRIAN
VON MÜHLENEN, University of Warwick (sponsored by Adrian von
Mühlenen)—Invariant contextual information supplies an important
source for behavioral orienting. For example, in the contextual cuing
paradigm, repetitions of the spatial layout of a search display implicitly
guide spatial attention to the target. The present study explored
how the segmentation of the search items into distinct groups influences
the contextual cuing effect. Experiment 1 demonstrated that if
displays were grouped by color, the contextual cuing effect was reduced.
Grouping by size led to an even larger reduction of the cuing
effect (Experiment 2). Finally, a subsequent experiment showed that
selectively attending to the relevant subgroup of search items preserved
contextual learning. Taken together, our findings suggest that
contextual cuing is modulated by perceptual grouping. This modulation
is larger when spatial as opposed to surface features are varied.
This is consistent with the view that contextual associations are primarily
learned within the segmented group of items.
(1048)
An Object-Based Attentional Repulsion Effect. SARA A. STEVENS
& JAY PRATT, University of Toronto—The attentional repulsion effect
(ARE) is a spatial consequence of shifting attention to peripheral locations
in the visual field. Previous research has shown that a brief peripheral
cue produces a shift in the perceived location of a Vernier
stimulus in the opposite direction to where the peripheral cue was located.
The ARE is therefore known to affect dorsal stream processing;
the influence of the ARE on the ventral stream, however, is unknown.
The present study examines whether object-based ventral
stream processing is affected by the ARE, using peripheral (Experiment
1) and central (Experiment 2) cues. Peripheral cues produced an