题目：Brain mechanisms of intuitive problem solving in board game experts

报告人：Keiji Tanaka （RIKEN Brain Science Institute)

时间：2014年08月28日 星期四 17:00-18:00

地点： 北京大学金光生命大楼（生命科学学院）411会议室

邀请人: Yuji Naya

摘要：Psychological studies of cognitive experts have shown that unconscious, automatic process is essential for their superior capability. The process is often referred to as “intuitive,” because it is quick and cannot be explained. Board games provide a good opportunity to study mechanisms underlying cognitive expertise, because the games are played in accordance with a set of well-defined rules. In an early study (de Groot 1946), both world-class and local-club players were asked to think aloud while playing spot games of chess, and no difference was found in the depth or width of search between the two groups. Instead, a difference was found in the selection of game tree branches that the player put into search: the best next-move was always included in the first part of search in world-class players, whereas local-club players often missed it in their large search. de Groot inferred that world-class players generate one or a few best next-moves by cued recall, not by search. Subsequently, it was found that chess experts quickly perceive chess patterns using various stereotyped arrangements of several pieces, called “chunks,” as units of perception (Chase and Simon, 1973). The perception of chunks may automatically generate an idea of the best next-move in chess experts. Despite these rich psychological studies, neural substrates of the automatic processes have not been revealed. We examined brain activity during generation of the idea of the best next-move to a given board pattern by using fMRI. Whereas distributed association cortical sites were activated, as expected, when the subject was allowed to think consciously for 8 s for each board pattern, the head of the caudate nucleus, a part of the basal ganglia, was also recruited when the subject was given only 1 s and had to solely depend on intuitive generation. The activation in the caudate head was stronger and more consistent in professional players than in amateurs. Moreover, when we trained novices for fifteen weeks to learn a simple board game, the activation in the head of caudate nucleus developed over the course of training, in parallel to the development of the capability to quickly generate the idea of the best next-move. These results suggest that the board-game expertise is supported by the specific neural circuit involving the caudate head, which implements the automatic processes of next-move generation.