ABSTRACT
Interest in the use of eyeblink classical conditioning procedures as a tool in the investigation of memory and learning problems in neurological patients began in the late 1970s. By that time, it was well established that the medial temporal lobe, especially the hippocampus, play a critical role in the formation of new memories; lesions to this area lead to profound amnesia in human subjects (Milner, 1971). In the animal literature, the search for the neural substrate of simple learning, such as classical conditioning of the nictitating membrane (NM)/eyeblink response, had also concentrated on the hippocampus (see Chapters 4 and 11). Significant correlations between hippocampal pyramidal cell activity and the course of learning during acquisition of conditioned eyeblink responses (CRs) suggested that learning-related plastic changes occur in the hippocampus. Support for this hypothesis came from several major findings. These included large differences in hippocampal unit activity in trials with and without a behavioral CR and parallels in the temporal shifts of response latencies of hippocampal and behavioral responses during the course of learning. In addition, the neural response was predictive of the temporal morphology of the behavioral CR within a trial (Thompson et al., 1980).
