Abstract

The rum of this study was to examine the effects of hippocampal lesion on the classical second-order conditioning of rabbit's nictitating membrane responses. The present experiment was carried out in a single stage which entailed randomly intermixing CS2-CS1 and CS1-US pairings. The subjects were 16 naive male albino rabbits. Half of the animals were randomly assigned to hippocampal lesioned group, and the other half to sham-operated control group. Results showed that the level of responding to CS2 in the hippocampal group reached a maximum of 15% CRs while the control group yielded a terminal level of approximately 60% CRs. The results suggest that hippocampus is involed in second-order conditioning. These findings were discussed in terms of stimulus map theory of Patterson.