The Basal Ganglia and Cognition

Abstract

Clinical evidence, experimental studies in animals, and anatomical findings suggest that the basal ganglia act to influence not only motor behavior but also cognitive functions. We discuss the functions of the basal ganglia in relation to four categories: (1) movement release and inhibition, (2) response selection, (3) attention and assignment of salience, and (4) learning and adaptive control of behavior. In establishing these functions, striatal output neurons lead into different output pathways: the direct, indirect, hyperdirect, and striosomal pathways. Divergence of cortical inputs to the striatum and reconvergence of these motor and cognitive signals in cortico-basal ganglia pathways is seen as essential in remapping forebrain representations of action and intrastriatal networks in the binding process. We propose that a crucial feature of this remapping is a learning-related recoding of sequential motor and cognitive action representations so that they can be expressed as units. This chunking function of the striatum and associated cortico-basal ganglia loops may be a key mechanism operative across each of the functional categories of behavioral control attributed to the basal ganglia.