S1 (FriAM 1-65) - The Psychonomic Society

Friday Noon Posters 2104–2111
mance does, however, lead to better sensitivity. Overall, conformance
accounts for 85% of the variance across both locations.
(2104)
Multiple Somatosensory Frames of Reference: Evidence From the
Simon Effect. JARED MEDINA, University of Pennsylvania, &
BRENDA RAPP, Johns Hopkins University—Individuals respond more
slowly even in nonspatial tasks when the stimulus and response are on
different sides of space—this is known as the Simon effect (Simon &
Small, 1969). Explanations assume that spatial codes are automatically
generated for both stimulus and response within specific spatial
reference frames. We present the results of a novel application of the
“Simon effect paradigm” to examine tactile reference frames. We report
evidence of multiple tactile reference frames. Specifically, when
participants’ arms are uncrossed, we find that allocentric, objectrelative
tactile stimulus codes are generated. However, when participants’
arms are crossed, an egocentric, somatotopic reference frame
is engaged (e.g., the left hand is encoded as left regardless of hand position).
We discuss these findings within a tactile processing framework
that includes somatotopic and nonsomatotopic stages of spatial
representation and processing.
• SPATIAL REPRESENTATIONS •
(2105)
Selecting a Reference Object. LAURA A. CARLSON, MARK R.
WILLIAMS, & PATRICK L. HILL, University of Notre Dame—Spatial
descriptions such as “The stapler is behind the binder” specify the
location of a target (stapler) by spatially relating it to a reference object
(binder) whose location is assumed to be easily found due to its
salience relative to other surrounding objects. Using line drawings and
real object displays, we assessed the importance of three candidate dimensions
for defining salience: spatial, perceptual, and conceptual.
Participants described the location of a target within displays containing
multiple candidate reference objects. For spatial salience, candidate
objects were placed in more preferred or less preferred spatial
relations to the target. For perceptual salience, one candidate reference
object was uniquely colored. For conceptual salience, one candidate
reference object was the criterion object in a prior categorization task.
The results indicate a strong preference to select reference objects on
the basis of their spatial relation to the target, with perceptual attributes
having a stronger influence than conceptual attributes.
(2106)
Perspective in Spatial Memory and Descriptions: Transforming
Representations for Communication. SARAH KRIZ, Naval Research
Laboratory, & MARY HEGARTY, University of California, Santa
Barbara—This study evaluated how spatial perspective is mentally
represented and the extent to which limits in representational flexibility
affect linguistic communication. In three experiments, participants
learned an environment through direct navigation or map viewing.
Later, they were asked to describe the environment from a
perspective that matched or mismatched their learned perspective. Descriptions
were analyzed to test three representational models: (1) spatial
representations are perspective-free, (2) spatial representations
encode multiple perspectives, and (3) spatial representations encode
the learned perspective, and are transformed to access the other perspective
when required by the communicative situation. Data from the
three experiments were best explained by the transformation model,
and the results suggest that transformations of spatial representations
to an unlearned perspective are subject to cognitive limitations.
(2107)
Cue Effects on Memory for Location When Navigating Spatial
Displays. SYLVIA FITTING, DOUGLAS H. WEDELL, & GARY L.
ALLEN, University of South Carolina (sponsored by David E.
Clement)—Participants maneuvered a mouse icon smoothly through
a circular region on the computer screen to find a hidden platform in a
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procedure that blended aspects of the Morris water maze task and the
dot location task. Predictions for effects of varying number of surrounding
cues (1, 2, or 3) were generated from a model of cue-based
memory error and bias (Fitting, Wedell, & Allen, in press). The pattern
of biases and errors was consistent with those predictions. Memory performance
decreased with decrease in number of cues, as measured by
number of moves to reach the target location and absolute heading error.
As memory performance declined, bias effects increased, as measured
by heading bias in the first 10 navigational steps and positional bias in
the last 10 steps. Remembered locations were biased toward the nearest
cue, and error decreased as a function of proximity to cue locations.
(2108)
To Go in Circles or Forge Straight Ahead: Depicting Cyclical
Processes. ANGELA KESSELL, Stanford University, & BARBARA
TVERSKY, Columbia University and Stanford University—Schematic
forms in depictions, such as lines, boxes, and arrows, can convey
meanings about concepts and relations that are readily understood in
context. Here, we investigate production and comprehension of depictions
of cyclical processes such as cell division and washing
clothes. When restricted to a circular display, people tend to put a natural
first step in the 12 o’clock position, with subsequent steps clockwise;
they also interpret the 12 o’clock step as the first one unless
there is a natural first step elsewhere. When not restricted to a circular
display, people tend to depict cyclical processes linearly.
(2109)
Learning the Layout of a New Building: A Longitudinal, Real-World
Study. DREW DARA-ABRAMS & MARY HEGARTY, University of
California, Santa Barbara (sponsored by Jack M. Loomis)—Over the
course of an academic year, we followed faculty members and graduate
students as they learned the layout of a new addition to the psychology
building at the University of California, Santa Barbara. At
three times during the year, participants generated route directions between
locations in the new and old buildings, which are connected by
catwalks spanning a courtyard. As each of the three floors in both
buildings has a different layout, route directions appeared to follow
one of three strategies: first head in the destination’s direction, first
head to the destination’s floor, or first go to the ground floor. Route
efficiency was evaluated based on path length, and floor plans were
used to compute a visibility graph, which indicated which routes were
the most visually integrated and contained the fewest turns. We will
report the effects of both visibility and learning on strategy choice.
(2110)
Inducing Hierarchical Representations: Consequences for Spatial
Heuristics. SIMON J. BUECHNER & CHRISTOPH HOELSCHER,
University of Freiburg (sponsored by Daniel R. Montello)—Two experiments
investigated people’s mental representation of a regularly
shaped building and related path choice heuristics. Experiment 1 applied
a structure mapping task, indicating that people spontaneously
group landmarks within their mental representation according to
structural characteristics of the environment (horizontally/vertically).
We also showed that the selection of a path choice heuristic was directly
related to the representation’s structure. Experiment 2 induced
one of the two major groupings in the mental representation by leading
the participants through the building either horizontally or vertically.
Participants performed verification and production tasks with
landmarks along an imagined path. Reaction times in within-group
tasks were faster than those in across-group tasks, showing that participants
organized their representation according to the way they
were exposed to the building. The experiments provide evidence that
a person’s mental representation is sensitive to both the environment’s
structure as well as to the way it is experienced.
(2111)
Learning of Absolute and Relative Distance and Direction by
Pigeons. BRADLEY R. STURZ, Armstrong Atlantic State University,