Role of contextual discrimination in fear conditioning.

Abstract

Trained 48 naive male Long-Evans rats to stable lever-pressing response rates in 2 free-operant situations that differed markedly in terms of contextual cues, given varying experience with preconditioning exposures to a CS (PCS), fear conditioned, and tested for suppression to the fear-conditioned CS. Analyses of variance and a Newman-Keuls test showed that (1) suppression trials in the chamber where PCS was administered produced significantly less suppression than trials in a situation where PCS was not administered, (2) this effect was due to fear conditioning and not to sensitization, and (3) extinction occurred. Data supported a discrimination hypothesis as PCS did not eliminate the effectiveness of the CS at a later time unless PCS exposure and testing occurred in the same location. (PsycINFO Database Record (c) 2006 APA, all rights reserved)