Frontal Cortex Lesions and Fixed-Interval Acquisition in the Rat

Abstract

This research was designed to study the behavioral effects of frontal cortex lesions upon the performance of rats in a fixed-interval reinforcement situation. Prior to testing, 10 Ss were prepared with posterior frontal cortical lesions in areas 10 and 6. 10 control Ss received sham operations. Following post-operative recovery, the animals were placed on a 23-hr. food deprivation schedule and trained to press a bar for a pellet of food which would be delivered only if 1 min. had elapsed since the previous reward. Analysis of variance showed no significant difference between the 2 groups in the ability to learn the temporal discrimination. However, lesioned Ss yielded a significantly divergent distribution of responses within the interval and a much lower terminal rate of response than the controls.