Abstract
This study investigated the degree to which intracranial electrical stimulation (test stimulus) would evoke a CR [conditioned response] that had been originally trained to a photic stimulus. Rats with chronically implanted electrodes were initially trained to press a lever for food with light as CS [conditioned stimulus], CRs to the test stimulus were extinguished, and generalization of extinction to the original CS (light) was tested. Responding to the test stimulus was highest for the optic chiasma, followed by occipital cortex, superior colliculus, and the frontal cortex in decreasing order. There was no difference between groups in the extinction rate to the original CS.