A Cortico-Subcortical System Controlling Differentiation Ability

Abstract

Publisher Summary This chapter discusses the results of a study analyzing a cortico-subcortical system controlling differentiation ability. The study was undertaken to reveal the role of cortical and subcortical structures of the dog that are involved in the suppression of conditioned responses in inhibitory trials. A local conditioned reflex type 11 of the foreleg reinforced by food and an inhibitory reflex were trained. Daily 10–15 positive and inhibitory trials with an interval of 1 min were used. The animals were trained to a criterion of stability of the positive and inhibitory reflexes. Upon completion of the preoperative training, each animal underwent a bilateral full or partial lesion of one of the following brain regions—the prefrontal cortex, the cingulate cortex, the dorsomedial and anterior nuclei of the thalamus, and the amygdaloid complex. Immediately after lesions of the medial frontal areas, errors occurred in positive trials. Within a few days, the positive reflexes recovered, however, and errors of disinhibition then occurred. It was suggested that the anteromedial prefrontal cortex, together with the genual area of the cingulate gyrus and the basolateral amygdaloid complex, constitutes a system, concerned with the type of inhibition trained in a situation where food is presented in positive trials.