To be a part of modern society, each person must be able to efficiently process various types of information and generate appropriate information to control one's behavior. This sequence of processes is performed by the nervous system, of which the association areas of the cerebral cortex and related structures like the basal ganglia are highly developed in humans, and are believed to play significant roles. From functional and structural viewpoints, our group strives to reveal the neuroscientific bases, which support social activities, by 1) reducing a scene of social activity into a simpler model task and directly measuring neuronal activities in an organism as a task is performed, and 2) elucidating the brain networks centered around the association areas of the cerebral cortex using various anatomical methods.