2018 Volume 35 Issue 3 Pages 158-167
Visual search is the first step for humans’ shopping and animals’ foraging. “Object skill” is an important skill for quickly detecting a valuable object and deciding to accept or reject it. Rhesus monkeys (Macaca Mulatta) show remarkable performance for quickly finding a “good object” among many objects after repetitive object-reward association learning. Monkeys can discriminate many good objects from many bad objects (〜300 objects) for long time after learning (more than 100 days). What neuronal circuits enable animals to retain this high-capacity and long-term memory for finding valuable objects? Our previous and current studies indicate that the basal ganglia circuits are involved in detecting good or bad objects and making saccade to good objects based on this memory. Our optogenetic and neuropharmacological experiments demonstrated that two parallel circuits in the basal ganglia work in a coordinated manner for the object skill. Direct pathway in the basal ganglia, which is activated by presentation of good objects, facilitates saccade to good objects. Indirect pathway, which is activated by presentation of bad objects, suppressed saccade to bad objects. Not only accepting good objects but also rejecting bad objects is critical for finding and selecting a valuable object among many objects.
