ROLE OF CONDITIONED CONTEXTUAL STIMULI IN REINSTATEMENT OF EXTINGUISHED FEAR

Results of 3 experiments with 80 female Wistar rats show that shocks presented to Ss following the extinction of conditioned suppression reliably reinstated suppression to the CS, but only when they were presented in the context in which testing was later to occur. Reinstatement was also reversed by extinguishing fear to the context through nonreinforced exposure to the context between shock presentation and testing. Reinstatement was obtained in spite of procedures that have been used in the past to minimize the influence of context conditioning. Moreover, fear of the context was never detected directly by depressed barpress rates in the absence of the CS. Results do not support the hypothesis that reinstatement results from an increment in the strength of a memory of the UCS that has been weakened during extinction. (29 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1979 American Psychological Association.