Evaluating equivalence relations in rats using an olfactory matching-to-sample procedure
- UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
- L. Brooke Poerstel (Creator)
- Institution
- The University of North Carolina Wilmington (UNCW )
- Web Site: http://library.uncw.edu/
- Advisor
- Mark Galizio
Abstract: Equivalence classes can be characterized as groups of stimuli which control
responding based on relations among members of the class, rather than absolute stimulus
features such as shape, size, or color. Formation of equivalence classes often includes
conditional discrimination training, which establishes contingency relations between
physically dissimilar, arbitrary stimuli using a Match-To-Sample (MTS) paradigm. If,
through the conditional discrimination training, the arbitrary stimuli become members of
predetermined equivalence classes, then four untrained properties of equivalence classes
(identity or reflexivity, symmetry, transitivity, and equivalency) should also emerge
during test configurations. Unlike humans, evidence of responding characteristic of
equivalence class formation in nonhuman animals is rarely, if ever, found. Regardless,
classification of environmental stimuli based on abstract, relational features may be a
fundamental aspect in learning and adaptation, as well as a possible indication of
nonhuman symbolic behavior. The equivalence model also provides a parsimonious
account of the often complex social and communicative behaviors observed in nonhuman
animals in natural settings. Perhaps traditional laboratory equivalence procedures require
modification such that these behaviors may be more readily observed in nonhuman
subjects. The current paper evaluated whether rats could demonstrate (1) acquisition of
conditional discriminations, both identity and arbitrary, within the training framework
and (2) relational responding in the presence of novel testing configurations (emergence
of generalized identity matching, symmetry, transitivity, and equivalence relations)
through a modified MTS procedure using olfactory stimuli and class-specific reinforcers.
Three experiments were conducted to evaluate generalized identity MTS (Experiment 1), arbitrary MTS and emergent equivalence (Experiment 2), and training experience effects
on emergent equivalence performance (extensive identity MTS pre-training versus no
identity MTS pre-training, Experiment 3). Subjects, 11 Male HSD rats, were trained to
retrieve reinforcers from cups of scented sand, which served as the stimuli throughout the
experiment. Nine subjects were trained identity MTS discriminations during Experiment
1. Five of the nine demonstrated convincing evidence for generalized identity matching.
The same five animals were then trained arbitrary MTS discriminations and given
emergent equivalence tests during Experiment 2. Four of the five Experiment 2 subjects
performed above chance during equivalence tests. Experiment 3 consisted of arbitrary
MTS training with two naïve subjects that had no identity MTS experience. One
Experiment 3 subject received an emergent equivalence test, but did not perform above
chance levels. The results of the three experiments suggest that olfactory stimuli and
class-specific reinforcers allow for transfer of responding during both generalized identity
and emergent equivalence tests. The exact effect of pre-training on emergent equivalence
performances is still unclear, as the results of Experiment 3 are currently inconclusive.
Evaluating equivalence relations in rats using an olfactory matching-to-sample procedure
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Additional Information
- Publication
- Thesis
- A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Arts
- Language: English
- Date: 2009
- Keywords
- Rats--Research
- Subjects
- Rats -- Research