Brain networks are decoupled from external stimuli during internal cognition
Brain networks are decoupled from external stimuli during internal cognition
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DOI：
10.1016/j.neuroimage.2022.119230
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发表时间：
2022-05-12
期刊：
影响因子：
5.7
通讯作者：
Nishimoto, Shinji
中科院分区：
文献类型：
--
作者：
Cohen, Dror;Nakai, Tomoya;Nishimoto, Shinji
我们的认知可以针对外部刺激或内部信息。虽然内部认知有许多不同的形式（走神、回忆、想象等），但它们的基本特征是独立于直接的感觉输入，概念上称为知觉解耦。感知解耦被认为反映在大脑活动从刺激处理模式转变为内部处理模式时，但对此的直接研究仍然悬而未决。在这里，我们提出了一个概念和分析框架，该框架量化了大脑网络反映刺激处理的程度。我们通过向受试者提供视听刺激并指示他们关注刺激（外部任务）或参与心理想象、回忆或算术（内部任务），同时使用功能性 MRI 测量诱发的大脑活动来测试该框架。我们发现，内部任务的刺激反应通常会减弱，尽管在任务和大脑网络的子集中刺激反应会增加。然而，使用我们的新框架，我们发现大脑网络对刺激处理的反映越来越少，即使在刺激反应增加的任务和大脑网络子集中也是如此。这些结果定量地表明，在内部认知过程中，大脑网络与外部刺激脱钩，为内部认知的基本和定量理解打开了大门。
Our cognition can be directed to external stimuli or to internal information. While there are many different forms of internal cognition (mind-wandering, recall, imagery etc.), their essential feature is independence from the immediate sensory input, conceptually referred to as perceptual decoupling. Perceptual decoupling is thought to be reflected in brain activity transitioning from a stimulus-processing to internally-processing mode, but a direct investigation of this remains outstanding. Here we present a conceptual and analysis framework that quantifies the extent to which brain networks reflect stimulus processing. We tested this framework by presenting subjects with an audiovisual stimulus and instructing them to either attend to the stimulus (external task) or engage in mental imagery, recall or arithmetic (internal tasks) while measuring the evoked brain activity using functional MRI. We found that stimulus responses were generally attenuated for the internal tasks, though they increased in a subset of tasks and brain networks. However, using our new framework, we showed that brain networks became less reflective of stimulus processing, even in the subset of tasks and brain networks in which stimulus responses increased. These results quantitatively demonstrate that during internal cognition brain networks become decoupled from the external stimuli, opening the door for a fundamental and quantitative understanding of internal cognition.