Abstracts 2005 - The Psychonomic Society

Papers 293–299 Sunday Morning
of phoneme repetition in the spoken production of short phrases were
explored. Participants named colored pictures with an adjective–noun
phrase; the central manipulation concerned whether or not segments
within the adjective and the noun matched (green gun, red rug) or mismatched
(red gun, green rug). A robust facilitatory effect of phoneme
match was found, suggesting that speakers planned the entire phrase
before they initiated a response and that repeated selection of the same
phoneme conferred a processing benefit. Further experiments demonstrated
that the effect of phoneme repetition is phonological, not articulatory,
in nature, and that it is largely independent of the position
of the matched segment within each word. Implications for theories
of phonological encoding and advance planning are discussed.
9:40–9:55 (293)
Speech Errors Reflect Newly Learned Phonotactic Constraints.
JILL A. WARKER & GARY S. DELL, University of Illinois, Urbana-
Champaign (read by Gary S. Dell)—If speakers repeatedly produce a
set of syllables in which all occurrences of, say, /f/ are syllable onsets,
and all /s/s are codas, their speech errors will rapidly come to reflect
these constraints. For example, when /f/s slip, they will slip to other
onset positions, not to coda positions. We attribute this effect to the
implicit learning of the phonotactic constraints within the experiment.
In four experiments, we show that more complex constraints, such as
/f/ appearing in an onset only if the vowel is /ae/, can also be acquired
and can influence speech errors. These constraints are learned much
more slowly, however. We present a model of the data to illustrate our
view that the language production system adapts to recent experience
while also continuing to reflect the accumulated experience of a lifetime
of speaking and listening.
10:00–10:15 (294)
Self-Monitoring of Sign Language: Implications for the Perceptual
Loop Hypothesis. KAREN D. EMMOREY, San Diego State University—Models
of speech production suggest that an inner, prearticulatory
loop and an external, auditory loop monitor the ongoing speech
flow. Speakers can monitor their speech output by listening to their
own voice—a perceptual loop feeds back to the speech comprehension
mechanism. Herein lies a critical difference between signed and
spoken language. The visual input from one’s own signing is quite distinct
from the visual input of another’s signing. To investigate how
signers monitor their production, normally sighted signers and signers
with tunnel vision due to Usher’s syndrome were studied. Evidence
suggests that signers visually monitor the location of their hands in
space but may not parse this visual input via the sign comprehension
mechanism. In addition, prearticulatory monitoring and perceptual
monitoring of another’s signing operate at different representational
levels (phonological vs. phonetic). I argue that self-monitoring via a
perceptual loop may be less critical for signed than for spoken language.
Movement and Perception
Conference Rooms B&C, Sunday Morning, 8:00–9:40
Chaired by Michael K. McBeath, Arizona State University
8:00–8:15 (295)
Pursuers Maintain Linear Optical Trajectory When Navigating to
Intercept Robots Moving Along Complex Pathways. MICHAEL K.
MCBEATH, WEI WANG, THOMAS G. SUGAR, IGOR DOLGOV, &
ZHENG WANG, Arizona State University—This study explores the
lateral navigational strategy used to intercept moving robots that approach
along complex pathways. Participants ran across a gymnasium
equipped with an eight-camera, high-resolution motion capture system
and tried to catch a robot that varied in speed and direction. Participant
behavior was compared with predictions of three lateral control
models, each based on maintenance of a particular optical angle
relative to the target: (1) constant alignment angle (CAA), (2) constant
bearing angle (CBA), and (3) linear optical trajectory (LOT). The results
were most consistent with maintenance of a LOT and least con-
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sistent with CBA. The findings support the idea that pursuers use the
same simple optical control mechanism to navigate toward complexly
moving targets that they use when intercepting simple ballistic ones.
Maintenance of a linear optical trajectory appears to be a robust, generalpurpose
strategy for navigating to interception of targets headed off to
the side.
8:20–8:35 (296)
Event Path Perception: Recognition of Transposed Spatiotemporal
Curves. THOMAS F. SHIPLEY, Temple University—An event can be
recognized as similar to another (although, logically, events are seen
only once). How can we understand this achievement? Aspects of
event perception may allow direct analogies to the better-understood
domain of object perception. If object recognition models are to serve
as the basis for models of event recognition, events should be recognized
following spatial transpositions, just as objects are recognized
following translation, rotation, or size change. Object paths (the trajectories
of objects through space) are recognized despite transpositions.
In this experiment, paths shown at one scale (e.g., a human walking
along a complex path in an open field) were accurately matched
to paths with different objects and different scales (e.g., a hand tracing
a path in the air). This is consistent with a model of event perception
in which paths of moving objects are decomposed at curvature
extrema with recognition based on the spatiotemporal shape of
the fragments.
8:40–8:55 (297)
Representational Momentum and Motion Capture. TIMOTHY L.
HUBBARD, Texas Christian University—In representational momentum,
memory for the final location of a moving target is displaced in
the direction of target motion. In motion capture, a stationary stimulus
is perceived to move in the same direction as a nearby moving target.
In the experiments reported here, a stationary stimulus was briefly
presented near the end or middle of a moving target’s trajectory. Memory
for the location of a stationary stimulus presented near the end of
the moving target’s trajectory was displaced in the direction of target
motion, and this displacement was larger with faster target velocities
and when the stationary stimulus was closer to the target. Memory for
the location of a stationary stimulus presented near the middle of the
moving target’s trajectory was not displaced. Representational momentum
of a moving target can influence memory for a nearby stationary
stimulus. Implications for theories of representational momentum
and of motion capture are considered.
9:00–9:15 (298)
Scene Movement Versus Observer Movement. CORY FINLAY,
MICHAEL MOTES, & MARIA KOZHEVNIKOV, Rutgers University,
Newark (read by Maria Kozhevnikov)—This research examined the
hypothesis that observer movement automatically updates representations
of scenes. In our initial study, observers memorized a spatial
array of ten objects from a single perspective. Then, either the scene
was rotated or participants moved around the scene (from 0º to 360º),
and participants judged whether the interobject spatial relations in the
array had changed. Regardless of whether the scene was rotated or observers
moved, greater angular disparity between judged and encoded
views produced slower RTs, suggesting that memory for the scene was
not automatically updated following observer movement. Furthermore,
varying set size (4, 6, 8, or 10 objects) and delay interval between encoding
and movement (0, 6, or 12 sec) produced decreased accuracy
and increased RT, with larger angular disparity between encoded and
judged views, regardless of set size and delay interval. These data
raise important questions regarding conditions under which spatial
updating does not occur.
9:20–9:35 (299)
It’s All About Me (Well Mostly): Identifying People From Their
Actions. SAPNA PRASAD, FANI LOULA, MAGDALENA GALA-
ZYN, & MAGGIE SHIFFRAR, Rutgers University, Newark (read by