2013年11月21日木曜日

Distinct contributions of the amygdala and parahippocampal gyrus to suspicion in a repeated bargaining game.

Bhatt MA, Lohrenz T, Camerer CF, Montague PR.
Proc Natl Acad Sci U S A. 2012 May 29;109(22):8728-33.

Bargaining GameのfMRI研究。
「他人の戦略をベイズ的に予想する」モデルを被験者の行動にフィット。
「他者の行動のバラつき」、「他者戦略推定の不確実性」がそれぞれ扁桃体と海馬で保持されている。

Humans assess the credibility of information gained from others on a daily basis; this ongoing assessment is especially crucial for avoiding exploitation by others. We used a repeated, two-person bargaining game and a cognitive hierarchy model to test how subjects judge the information sent asymmetrically from one player to the other. The weight that they give to this information is the result of two distinct factors: their baseline suspicion given the situation and the suspicion generated by the other person's behavior. We hypothesized that human brains maintain an ongoing estimate of the credibility of the other player and sought to uncover neural correlates of this process. In the game, sellers were forced to infer the value of an object based on signals sent from a prospective buyer. We found that amygdala activity correlated with baseline suspicion, whereas activations in bilateral parahippocampus correlated with trial-by-trial uncertainty induced by the buyer's sequence of suggestions. In addition, the less credible buyers that appeared, the more sensitive parahippocampal activation was to trial-by-trial uncertainty. Although both of these neural structures have previously been implicated in trustworthiness judgments, these results suggest that they have distinct and separable roles that correspond to their theorized roles in learning and memory.

0 件のコメント:

コメントを投稿