視床と注意

Thalamus and Attention

注意とは情報の選択であり，視床は視覚・聴覚情報の選択を行っている。必要な情報にスポットライトを当て，同時に周囲の背景を抑制することにより重要な情報を際立たせている。視覚情報を選択する場が外側膝状体（LGB）で，そのLGBを管理し情報の選択を強化しているのが視床網様核（TRN）である。さらに頭頂・側頭・前頭葉などから下されるトップダウン様式の注意を調整し，行動と結びつけているのが視床枕である。また自験の視床出血における注意障害について検討した。

Abstract

Attention is the process by which information and selection occurs, the thalamus plays an important role in the selective attention of visual and auditory information. Selective attention is a conscious effort; however, it occurs subconsciously, as well. The lateral geniculate body (LGB) filters visual information before it reaches the cortex (bottom-up attention). The thalamic reticular nucleus (TRN) provides a strong inhibitory input to both the LGB and pulvinar. This regulation involves focusing a spotlight on important information, as well as inhibiting unnecessary background information. Behavioral contexts more strongly modulate activity of the TRN and pulvinar influencing feedforward and feedback information transmission between the frontal, temporal, parietal and occipital cortical areas (top-down attention). The medial geniculate body (MGB) filters auditory information the TRN inhibits the MGB. Attentional modulation occurring in the auditory pathway among the cochlea, cochlear nucleus, superior olivary complex, and inferior colliculus is more important than that of the MGB and TRN. We also discuss the attentional consequence of thalamic hemorrhage.