2023-07-19 カリフォルニア大学バークレー校(UCB)
◆脳科学者たちは、何かを認識することと、その認識に気付くこととの違いを解明するために、脳のどの領域で長期間にわたって視覚的なイメージが保持されるのかを発見したと報告しています。この研究結果は、将来的には昏睡患者の脳活動を調べることで、その人が外界に対して意識を持っているかを判断し、治療法の開発にも応用されるかもしれません。
<関連情報>
- https://news.berkeley.edu/2023/07/19/study-sheds-light-on-where-conscious-experience-resides-in-brain/
- https://www.cell.com/cell-reports/fulltext/S2211-1247(23)00763-5
意識的な視覚知覚が持続している間、腹側皮質と前頭前野の表象ダイナミクスは異なる Distinct ventral stream and prefrontal cortex representational dynamics during sustained conscious visual perception
Gal Vishne,Edden M. Gerber,Robert T. Knight,Leon Y. Deouell
Cell Reports Published:July 07, 2023
DOI:https://doi.org/10.1016/j.celrep.2023.112752
Highlights
•ECoG reveals encoding of categories and exemplars for images of varying durations
•Sustained visual information is represented with varying dynamics across the brain
•Occipitotemporal distributed representations are sustained, tracking image duration
•Frontoparietal distributed representations are transient, following stimulus onset
Summary
Instances of sustained stationary sensory input are ubiquitous. However, previous work focused almost exclusively on transient onset responses. This presents a critical challenge for neural theories of consciousness, which should account for the full temporal extent of experience. To address this question, we use intracranial recordings from ten human patients with epilepsy to view diverse images of multiple durations. We reveal that, in sensory regions, despite dramatic changes in activation magnitude, the distributed representation of categories and exemplars remains sustained and stable. In contrast, in frontoparietal regions, we find transient content representation at stimulus onset. Our results highlight the connection between the anatomical and temporal correlates of experience. To the extent perception is sustained, it may rely on sensory representations and to the extent perception is discrete, centered on perceptual updating, it may rely on frontoparietal representations.
