FORCED CIRCLING IN MONKEYS FOLLOWING LESIONS OF THE FRONTAL LOBES

Abstract

Uni-lateral ablation of area 8 from the frontal lobes of Macaco, mulatla is followed by transient deviation of the head and eyes toward the side of the lesion. In addition such animals exhibit circling movements in the same direction which persist after the head and eye deviation has disappeared, which are "forced" in character and which are augmented by the emotional stimuli of fear, rage, etc. There appears also a failure to respond in the normal manner to visual stimuli in the contralateral field of vision. Bilateral removal of area 8 is followed by alterations in behavior in response to visual stimuli and by changes in total activity which becomes increased and of a stereotyped nature.