LONG-TERM-MEMORY AND EXTINCTION OF THE CLASSICALLY-CONDITIONED RABBIT NICTITATING-MEMBRANE RESPONSE

The purpose of the present experiment was to examine the duration of long-term memory for classical conditioning of the rabbit nictitating membrane response (NMR). Anecdotal accounts of memory for the rabbit NMR suggest that a conditioned nictitating membrane response (CR) may occur as long as a year after acquisition. The data from the present between-subjects experiment indicate that CRs (1) are robust if tested after 1 month, (2) still occur if tested after 3 months, and (3) are initially absent if tested after 6 or 9 months but then reemerge over the course of extinction. The data also indicate that reacquisition of CRs 6 or even 9 months after training is significantly more rapid than original acquisition and thus represents a substantial level of savings. These results provide the first systematic, empirical assessment of the long-term memory capacity of the rabbit for classical conditioning of the NMR and suggest that the rabbit NMR preparation is a model suitable for studying the behavioral and physiological processes involved in long-term memory, retention, and forgetting. © 1993 Academic Press, Inc.