Memoria temporal coding

Journal of Experimental Psychology: Animal Behavior Processes 2004, Vol. 30, No. 3, 190 –202

Copyright 2004 by the American Psychological Association 0097-7403/04/$12.00 DOI: 10.1037/0097-7403.30.3.190

Temporal Coding in Conditioned Inhibition: Analysis of Associative Structure of Inhibition
Appalachian State University

James C. Denniston

University of California, Los AngelesAaron P. Blaisdell

State University of New York at Binghamton

Ralph R. Miller

Two experiments with rats as subjects were conducted to investigate the associative structure of temporal control of conditioned inhibition through posttraining manipulation of the training excitor– unconditioned stimulus (US) temporal relationship. Experiment 1 found that following simultaneous Pavlovian inhibitiontraining (i.e., A 3 US/XA-no US) in which a conditioned stimulus (CS A) was established as a delay excitor, maximal inhibition was observed on a summation test when CS X was compounded with a delay transfer CS. Furthermore, posttraining shifts in the A-US temporal relationship from delay to trace resulted in maximal inhibition of a trace transfer CS. Experiment 2 found complementary results toExperiment 1 with an A-US posttraining shift from serial to simultaneous. These results suggest that temporal control of inhibition is mediated by the training excitor-US temporal relationship.

Students of animal learning have been interested in the phenomenon of behavioral inhibition since the pioneering work of Pavlov (1927). In a typical Pavlovian conditioned inhibition procedure, aconditioned stimulus (CS A) is followed by the unconditioned stimulus (US), except when it is compounded with a putative inhibitor (CS X; A 3 US/XA-no US). Behavior indicative of inhibition is typically assessed with two assays, the negative summation and retardation tests for inhibition (Hearst, 1972; Rescorla, 1969). A stimulus is said to be a conditioned inhibitor when it passes both tests. That is, itmust attenuate responding to an independently trained excitor when presented in compound with it (the summation test), and it must be slow to acquire behavioral control when paired with the US (the retardation test). Since the introduction of this two-test strategy for evidencing conditioned inhibition, much has been learned about the associative structure of conditioned inhibition. Prior studiesof the associative structure of inhibition found that subjecting an inhibitory CS to extinction treatment (i.e., X-no US presentations) prior to inhibition testing does not disrupt inhibitory behavioral control (e.g., Witcher & Ayres, 1984; Zimmer-Hart &

James C. Denniston, Department of Psychology, Appalachian State University; Aaron P. Blaisdell, Department of Psychology, University ofCalifornia, Los Angeles; Ralph R. Miller, Department of Psychology, State University of New York at Binghamton. Support for this research was provided by National Institute of Mental Health Grant 33881. We thank James Esposito for his technical support and Jeffrey Amundson, Leslie Gerrard, Oskar Pineno, Steven Stout, Gonzalo ˜ Urcelay, Kouji Urushihara, and Daniel Wheeler for comments on an earlierversion of this article. Correspondence concerning this article should be addressed to James C. Denniston, Department of Psychology, Appalachian State University, Boone, NC 28608. E-mail: dennistonjc@appstate.edu 190

Rescorla, 1974). In fact, extinction of the conditioned inhibitor has sometimes been found to enhance inhibitory behavioral control (DeVito & Fowler, 1987; Williams & Overmier, 1988).In contrast, subjecting the training excitor (CS A) with which the inhibitor was established to extinction often disrupts inhibitory behavioral control (e.g., Best, Dunn, Batson, Meachum, & Nash, 1985; Hallam, Matzel, Sloat, & Miller, 1990; Lysle & Fowler, 1985; but see Rescorla & Holland, 1977; Witcher & Ayres, 1984, for conflicting results). On the basis of their findings, Lysle and Fowler...