Acquisition and Retention of Response Patterns in Compound Classical Conditioning

Abstract

The acquisition and long-term retention of overt response patterns were recorded during compound conditioning with mice. A 10-sec light + tone compound was terminated by a food pellet unconditioned stimulus, with the subject’s relative location tracked by computer during control and stimulus intervals. Compound conditioning elicited a variety of response patterns, including uniformly brief orienting responses to the localized light and tone intermixed with variable duration responses to the food cup. The response patterns resulted in both a complementary inhibition and a sequential dependence between responses that remained relatively stable for 120 to 180 days following initial conditioning. The compound conditioned stimuli elicited a molecular or within-trial “overshadowing” effect, with food cup responses differentially dependent upon the prior occurrence of orienting responses to either the light or tone. Both the concurrent inhibition and sequential elicitation of responses in Pavlovian conditioning are consistent with previous analyses of response patterns in experimental schedules.