RESPONSES OF MONKEY BASAL FOREBRAIN NEURONS DURING VISUAL-DISCRIMINATION TASK

The chapter discusses the results of a study of organization in the monkey basal forebrain of visual information concerning real objects. It was found that basal forebrain neurons selectively coded information about reinforcement and novelty-familiarity relations, and have strong plastic neuronal responses that are related to learning. Monkeys with basal forebrain deficits had impairment of some kind of learning and memory, such as new visual object learning, relearning object discrimination, and serial reversal learning. The basal forebrain receives neuronal inputs from many areas, including the inferotemporal and entorhinal cortices, amygdala, hippocampus, and lateral hypothalamic area. Detailed experimental procedures are described. Single unit activity from the monkey basal forebrain, including the nucleus basalis of Meynert and the diagonal band of Broca was recorded during a visual discrimination task to study the contribution of the basal forebrain to visual learning and memory related to novel and familiar objects. The task included discrimination of rewarding or aversive objects, novel and familiar objects, and association or dissociation with stimulus-reinforcement relations. © 1993, Academic Press Inc.