Nentwich Maximilian, Leszczynski Marcin, Schroeder Charles E, Bickel Stephan, Parra Lucas C
The Feinstein Institutes for Medical Research, Northwell Health, Manhasset, United States.
Departments of Psychiatry and Neurology, Columbia University College of Physicians and Surgeons, New York, United States.
Elife. 2025 Jul 3;14:RP104996. doi: 10.7554/eLife.104996.
Sensory stimulation of the brain reverberates in its recurrent neural networks. However, current computational models of brain activity do not separate immediate sensory responses from this intrinsic dynamic. We apply a vector-autoregressive model with external input (VARX), combining the concepts of 'functional connectivity' and 'encoding models', to intracranial recordings in humans. This model captures the extrinsic effect of the stimulus and separates that from the intrinsic effect of the recurrent brain dynamic. We find that the intrinsic dynamic enhances and prolongs the neural responses to scene cuts, eye movements, and sounds. Failing to account for these extrinsic inputs leads to spurious recurrent connections that govern the intrinsic dynamic. We also find that the recurrent connectivity during rest is reduced during movie watching. The model shows that an external stimulus can reduce intrinsic noise. It also shows that sensory areas have mostly outward, whereas higher-order brain areas have mostly incoming connections. We conclude that the response to an external audiovisual stimulus can largely be attributed to the intrinsic dynamic of the brain, already observed during rest.
大脑的感觉刺激在其递归神经网络中回荡。然而，当前的大脑活动计算模型并未将即时感觉反应与这种内在动态区分开来。我们将一种带有外部输入的向量自回归模型（VARX）应用于人类颅内记录，该模型结合了“功能连接性”和“编码模型”的概念。此模型捕捉刺激的外在效应，并将其与大脑递归动态的内在效应区分开来。我们发现，内在动态增强并延长了对场景切换、眼球运动和声音的神经反应。未能考虑这些外在输入会导致控制内在动态的虚假递归连接。我们还发现，在观看电影期间，休息时的递归连接性会降低。该模型表明，外部刺激可以降低内在噪声。它还表明，感觉区域大多具有外向连接，而高阶脑区大多具有内向连接。我们得出结论，对外部视听刺激的反应很大程度上可归因于大脑的内在动态，这种动态在休息时就已被观察到。
