聴覚表象の形成に関する神経相関(脳画像計測と基礎心理学,第26回大会 シンポジウム2)

抄録

One of the central issues in brain science is how percepts are formed in the brain. Dissociations between physical stimulation and subjective experience provide an opportunity to clarify brain activity related to the formation of percepts. This article introduces findings from neuroimaging studies using auditory illusions. Prolonged listening to a repeated word without a pause produces illusory transitions of the unchanging word, which are called verbal transformations. The number of verbal transformations is positively and negatively correlated with activity in the left inferior frontal cortex and anterior cingulate cortex, respectively. The percept frequently switches between one coherent and two distinct streams when an unchanging triplet-tone sequence is presented. Activity in the thalamus or the auditory cortex occurs earlier during perceptual switching in auditory streaming. These findings suggest that short-term plasticity leading to the formation of auditory percepts is implemented in feedback and feed-forward loops between two brain regions.