The effect of hippocampal lesions on extinction and "hypothesis" behavior in rats.

Abstract The behavior of rats during the acquisition and extinction of a brightness discrimination was altered by bilateral hippocampal lesions. Lesions restricted to the neopallium overlying the hippocampus did not significantly affect behavior. While brain damage did not increase the number of trials required to reach the acquisition criterion, rats with hippocampal lesions did generate significantly longer position hypotheses during acquisition. During extinction, rats with hippocampal damage showed no increase in approach response latency and made significantly longer brightness, but not position hypotheses. These results, together with previous findings, strengthen the conclusion that the behavior of rats in low ratio reinforcement situations is particularly sensitive to the disruptive effects of hippocampal damage. Such damage may produce behavioral effects by altering the brain processes necessary for the shifts of attention which can be inferred to occur in normal animals in such situations.

[1]  A. Amsel.  Frustrative nonreward in partial reinforcement and discrimination learning: some recent history and a theoretical extension. , 1962, Psychological review.

[2]  D. Kimble,et al.  Hippocampal lesions and the orienting response. , 1969, Journal of comparative and physiological psychology.

[3]  L. Jarrard,et al.  Effects of hippocampal ablation and intertrial interval on acquisition and extinction in a complex maze. , 1967, The American journal of psychology.

[4]  D. Crowne,et al.  Hippocampal lesions and the cardiac component of the orienting response in the rat. , 1969, Journal of comparative and physiological psychology.

[5]  S. Siegel,et al.  Nonparametric Statistics for the Behavioral Sciences , 2022, The SAGE Encyclopedia of Research Design.

[6]  D. Kimble.  Hippocampus and internal inhibition. , 1968, Psychological bulletin.

[7]  R. Isaacson,et al.  Effect of the Introduction of an Irrelevant Stimulus on Runway Performance of the Hippocampectomized Rat , 1963, Nature.

[8]  R. Douglas,et al.  The effect of radical hippocampal ablation on acquisition of avoidance response. , 1961 .

[9]  Jarrard Le.  EFFECTS OF HIPPOCAMPAL ABLATION AND INTERTRIAL INTERVAL ON RUNWAY ACQUISITION AND EXTINCTION. , 1964 .

[10]  R. Douglas,et al.  The hippocampus and behavior. , 1967, Psychological bulletin.

[11]  K. Pribram,et al.  Learning and limbic lesions , 1966 .

[12]  H. Niki.  THE EFFECTS OF HIPPOCAMPAL ABLATION ON THE BEHAVIOR IN THE RAT , 1962 .

[13]  R. Douglas,et al.  The effect of limbic damage on the retention and performance of a runway response , 1966 .

[14]  I. Krechevsky.  Brain mechanisms and "hypotheses." , 1935 .

[15]  D. Kimble,et al.  Brightness discrimination and reversal in hippocampally-lesioned rats , 1968 .

[16]  D. Kimble.  The effects of bilateral hippocampal lesions in rats. , 1963, Journal of comparative and physiological psychology.

[17]  Sutherland Ns,et al.  THE LEARNING OF DISCRIMINATIONS BY ANIMALS. , 1964 .

[18]  R. Isaacson,et al.  Hippocampal lesions and the frustration effects in rats. , 1969, Journal of comparative and physiological psychology.