Cognitive functions of the GPe

The globus pallidus externus (GPe) is a central nucleus in the basal ganglia. Although traditionally defined as a component of the basal ganglia's motor circuit, converging evidence from humans, rodents, and non-human primates has established the GPe as a key contributor to the cognitive control of behavior. In this role, the GPe dynamically regulates goal-directed behavior in response to changing environmental demands. In this review, we highlight recent studies demonstrating that the GPe encodes cue and action values, supports behavioral flexibility, and modulates attention, behavioral inhibition, and habit formation. The picture that emerges is of a nucleus that aligns behavior to internal goals by constraining, updating, and optimizing ongoing actions.