共同注意の脳内機構

The Neural Mechanisms of Joint Attention

共同注意とは，視線や指差しを介して他者と注意を共有し，コミュニケーションの共通基盤をつくる行為である。他者からのシグナル受容（受動的），他者へのシグナル送信（能動的）という2種類の役割を経験することにより，乳児期に段階的に発達する。近年の研究から，背内側前頭前野，眼窩回・島，前・後部帯状回，上側頭回，楔前部・頭頂葉，扁桃体・腹側線条体を中心としたネットワークが共同注意の神経基盤として提唱されている。

Abstract

Joint attention behaviors involve sharing attention with others to an object or event by means of eye-gazing or pointing, which form the common basis for communication. There are two types of these behaviors: responding to joint attention (RJA) and initiating joint attention (IJA). RJA is the ability to follow the gaze of others, suggesting reception of a social signal from others; IJA is the ability to voluntarily direct the attention of others, to share the experience of an object or event, suggesting transmission of a social signal to others. Infants experience these roles (as signal receiver and signal transmitter) throughout the first year of life and learn social cognitive skills. Recent neuroimaging studies indicate that joint attention is supported by widely distributed neural systems with nodes in the dorsomedial prefrontal cortex, the orbitofrontal cortex and insula, the anterior and posterior cingulate cortex, the superior temporal cortex, the precuneus and parietal cortex, and the amygdala and striatum.