Amobarbital and the partial reinforcement effect in rats: Isolating frustrative control over instrumental responding.

Abstract

Each of 3 runway investigations contained 2 partial reinforcement (PRF) groups of female albino Holtzman rats. Extinction was preceded by injections of either amobarbital or saline. In acquisition, injections of amobarbital preceded nonrewarded trials followed by rewarded trials in 1 PRF group, and rewarded trials followed by nonrewarded trials in the other PRF group. Only the latter group showed a PRE in saline extinction. Both PRF groups showed a PRE in amobarbital extinction. Saline extinction was little affected by prior amobarbital extinction. Results isolate and identify the PRF trials on which frustration acquires control over the instrumental reaction and suggest that nonreward occasions emotionally neutral stimuli which can sustain a PRE. (23 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)