Friday Lunch Seminar
January 15, 2021
12:15 〜 13:00
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You will be notified of participation details by e-mail on Jan. 14.
Talk Title: “Brain networks are insulated from external stimuli during internal cognition”
Brain Networks and Communication Labortory
Center for Information and Neural Networks (CiNet)
National Institute of Information and Communications Technology (NICT)
Host: Shinji Nishimoto
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. This is thought to be reflected in the insulation of brain networks from the external stimuli, but a direct examination of this remains outstanding. Here we present a conceptual and analysis framework that links stimulus responses to connectivity within and between brain networks, allowing us to quantitatively assess the insulation of brain networks from the external stimulus. 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 arithmetic, recall or imagery (internal tasks). We found that although stimulus responses were generally attenuated during internal cognition, they increased in a subset of tasks and brain networks. In addition, connectivity between brain networks was more reflective of stimulus responses for the external task as compared to each of the internal tasks. Moreover, connectivity between brain networks was less reflective of the stimulus even for the subset of tasks and brain networks in which stimulus responses increased. These results quantitatively demonstrate that during internal cognition connectivity between brain networks is insulated from external stimuli.