Abstracts 2005 - The Psychonomic Society

Saturday Noon Posters 4107–4112
University of Western Ontario—The triad classification task presents
participants with a target concept and two possible associates. These
associates are related to the target differently, allowing the researcher to
contrast two classification alternatives. Participants choose which alternative
to pair with the target concept. This task has been used to demonstrate
many conceptual and perceptual preferences, including whether
adults might prefer taxonomic groupings, such as bed and crib (Smiley
& Brown, 1979) or thematic groupings, such as baby and crib (Lin &
Murphy, 2001). We explore this issue further by examining the mode of
stimulus presentation (words or pictures) and the sex of participants.
Several experiments showed an overall preference for thematic classifications,
but this was attenuated when the stimuli were presented as pictures.
In particular, male participants tended to make taxonomic classifications
when presented with pictures and thematic classifications when
presented with words. We argue that classification preferences are dynamic
and are influenced by various stimulus properties.
(4107)
Modeling Categorization Response Times Using Decision Trees: A
Goodness-of-Fit Comparison of Rule-Based and Exemplar Models.
DANIEL LAFOND & YVES LACOUTURE, Université Laval (sponsored
by A. A. J. Marley)—Lamberts (2000) has modeled individual
categorization response data from 10 participants, using the extended
generalized context model and the exemplar-based random walk
model. In the present study, we used three rule-based classification
models proposed by Trabasso, Rollins, and Shaughnessy (1971) to fit
the same data. A decision tree consistent with the observed response
choices was first derived for each participant. The sequence of decisions
within each tree provides the basis for response time modeling.
Minimizing SSE with a quasi-Newton search algorithm allowed us to
estimate individual parameters. Two goodness-of-fit indicators were
used, MS e and R 2 . Results show that one of the rule-based models,
which has fewer free parameters than both exemplar models, provides
overall best fit. Some implications for modeling categorization
processes are discussed.
(4108)
Exemplar Models Seen as a Mixture of Serial Decision Rules. FABIEN
MATHY, Rutgers University, Piscataway (sponsored by Jacob Feldman)—This
poster reports a study of a decision tree model in Boolean
concept learning. The model aims to determine the minimal decision
tree corresponding to a concept. The time needed to classify a stimulus
(i.e., response time) is linked to the number of decisions that must
be made in order to know its category. When mixing all equivalent decision
trees for a given concept, the mean predicted response times are
perfectly correlated with those given by exemplar models. We present
an experiment including 84 subjects who learned and applied
Shepard’s (1961) Type IV concept. The mean response times fit both
decision tree and exemplar models. However, when the individual patterns
are looked at, the decision tree model explains the results better
than does the exemplar model in 69 out of 84 subjects.
(4109)
Knowledge Partitioning in Categorization Without Context. LEE-
XIENG YANG, National Chung Cheng University, & STEPHAN
LEWANDOWSKY, University of Western Australia (sponsored by
Stephan Lewandowsky)—Knowledge partitioning refers to the notion
that knowledge can be held in independent and nonoverlapping
parcels. People use a context cue to choose a knowledge parcel for responding,
while ignoring information held in other parcels. A number
of studies have reported evidence for such context-gated knowledge
partitioning in function learning (Lewandowsky, Kalish, &
Ngang, 2002) and categorization (Yang & Lewandowsky, 2003,
2004). In addition, knowledge partitioning has been observed in function
learning in the absence of context cues (Kalish, Lewandowsky, &
Kruschke, 2004). We report a study that examined whether knowledge
partitioning can occur without context cues in categorization. Partic-
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ipants were trained with separate clusters of stimuli located in different
regions of the category space and were found to learn two partial
rules for categorization, as is predicted by the knowledge-partitioning
framework. We show by simulation that a pure exemplar-based model,
such as the GCM, has difficulty accommodating these results.
(4110)
QMQ Shows Male Adolescent Sex Offenders Can Respond to Therapy.
R. CHRIS MARTIN, University of Missouri, Kansas City, DEBBIE
K. MARTIN, Quality Motivation Corporation, BONNIE E. POOLE
& LEAH K. GENSHEIMER, University of Missouri, Kansas City, &
SCOTT U. LEGRAND, Devereaux Florida Network—Adolescent male
sex offenders are recalcitrant therapy subjects for many reasons. A
midwestern Boy’s Town facility provided a structured environment
with many group sessions and several individual sessions weekly, with
an emphasis upon behavioral change. The Quality of Motivation
Questionnaire (c) is a true/false, computer-scored instrument that provides
38 scales, including amounts of positive and negative motivation,
energy level, emotional stability, depression, life styles, and
skills. Upon presentation, they were deceitful, depressed, and high in
maladaptive skills, such as self-sabotage, self-punishment, and a lack
of problem-solving abilities. Success of treatment was shown in statistically
significant changes in five areas: emotional stability, depression,
decision making, responsibility, and problem solving. Recommendations
are made regarding how to further improve adaptive
skills and reduction in the maladaptive ones. Depression scores, although
reduced, were still high, and specific changes are needed. The
attitude that sex offenders are immutable might need to change.
(4111)
Accessibility of Taxonomic and Script Knowledge in the Domain of
Food. ANNA Z. VITKIN, JOHN D. COLEY, & KONSTANTIN FEIGIN,
Northeastern University—Ross and Murphy (1999) showed that priming
improved the accessibility of script knowledge about food (apple
as snack), but not taxonomic knowledge (apple as fruit), relative to
neutral priming, suggesting that taxonomic knowledge is more accessible
to reasoning about food. We examined the effects of cross
priming, asking whether incongruent priming would differentially interfere
with accessibility of script versus taxonomic knowledge. Participants
read a sentence about a food that primed either taxonomic or
script knowledge. They then verified the food’s taxonomic or script
category membership (congruent or incongruent with priming). Overall
taxonomic decisions were faster and more accurate than script decisions.
Incongruent priming had no effect on taxonomic decisions,
whereas script decisions were significantly slower and less accurate
for incongruent primes. Taken together with Ross and Murphy (1999),
this suggests that not only is script knowledge less accessible overall,
but also it is actively inhibited by the activation of taxonomic knowledge.
(4112)
Who Do You Look Like? Further Exploration Into the Relationship
Between Names and Faces. MELISSA A. LEA, Union College, ROBIN
D. THOMAS, AARON T. BELL, NATHAN A. LAMKIN, & JEFF H.
SHOLL, Miami University—Many cognitive researchers support the
notion that names and facial features have no relationship with each
other (Bruce & Young, 1986; Burton & Bruce, 1992). However, Lea
(2002) showed that when participants are given a name and are asked
to provide a description of that person by rating second-order relational
features, they give similar descriptions of how that face should
look. For example, the name “Bob” provoked a description of a widefaced,
round-featured man, and “Tim” a thin-faced, thin-featured
man. Conversely, the present study was conducted to determine
whether participants would consistently label a set of prototype faces
with those names. That is, would participants give the wide-faced,
round-featured face the name “Bob”? The results demonstrate that
participants are reliable at giving names to prototype faces and support
the idea that faces and names can have a direct relationship.