The Effect of Prefrontal Leucotomy on the Psychogalvanic Response

Abstract

Though it is now generally accepted that prefrontal leucotomy has an effect on the subject's behaviour, its mode of action and the intermediate stages of its effect are still obscure. Some evidence, which has been sufficiently reviewed elsewhere (Meyer and McLardy, 1949; Fleming, 1944), suggests that the operation acts by lessening emotional drive: the retrograde degeneration which usually occurs in the dorso-medial and anterior thalamic nuclei points to this. Clinically, however, the belief rests on little more than impressions. In order to obtain more objective evidence, we have used the psychogalvanic response, not because it measures emotional change with fidelity, but because it is one of the few objective tests available. Though its precise relation to emotional change is still not clear, that it does have some relation has been demonstrated repeatedly. We have therefore attempted to compare the sizes of the response before and after the operation.