Activity levels and fixed interval performance in rats with septal lesions

Abstract

Six septal-lesioned and six sham-operated rats were trained on a 120-sec fixed-interval (FI) schedule of reinforcement until obvious "scalloping" was present. Then, general behavior was observed using a 10-sec time-sampling technique. Compared to sham-operated controls, animals with septal lesions took more trials to reach criteria for response distribution on the FI and were more active and showed more investigatory responses. Because increased bar-pressing and increased activity could be dissociated in another experiment using negative reinforcement, it was suggested that the degree to which any "septal inhibitory deficit" is exhibited would seem to depend on the relative "potency" of the different motivational cues guiding behavior. © 1977 Academic Press, Inc.