Stimulus Discrimination through Intracranial Reinforcement

Abstract

5 satiated rats and a guinea pig with chronically implanted electrodes were operantly conditioned to respond on a lever to receive intracranial self-stimulation (I.C.S.) under a multiple schedule of reinforcement. Response rates, under the control of visual or auditory discriminative stimuli, were appropriately high or low according to the requirements of the schedule. Alternating changes of the discriminative stimuli resulted in immediate shifting of response rates by Ss. Electrode placements were in the mammillary body area and the posterior hypothalamus. The findings indicate that I.C.S. reinforcement can be used to study discrimination acquisition in lower organisms.