Department of Education and Psychology, Freie Universität Berlin, Berlin 14195, Germany.
Mathematical Institute, Department of Mathematics and Computer Science, Physics, Geography, Justus-Liebig-Universität Gießen, Gießen 35392, Germany.
Sci Adv. 2023 Nov 10;9(45):eadi2321. doi: 10.1126/sciadv.adi2321.
During naturalistic vision, the brain generates coherent percepts by integrating sensory inputs scattered across the visual field. Here, we asked whether this integration process is mediated by rhythmic cortical feedback. In electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) experiments, we experimentally manipulated integrative processing by changing the spatiotemporal coherence of naturalistic videos presented across visual hemifields. Our EEG data revealed that information about incoherent videos is coded in feedforward-related gamma activity while information about coherent videos is coded in feedback-related alpha activity, indicating that integration is indeed mediated by rhythmic activity. Our fMRI data identified scene-selective cortex and human middle temporal complex (hMT) as likely sources of this feedback. Analytically combining our EEG and fMRI data further revealed that feedback-related representations in the alpha band shape the earliest stages of visual processing in cortex. Together, our findings indicate that the construction of coherent visual experiences relies on cortical feedback rhythms that fully traverse the visual hierarchy.
在自然视觉中，大脑通过整合分散在视野中的感觉输入来产生连贯的感知。在这里，我们想知道这个整合过程是否是由节律性皮质反馈介导的。在脑电图 (EEG) 和功能磁共振成像 (fMRI) 实验中，我们通过改变在视觉半视野中呈现的自然视频的时空相干性来实验性地操纵整合处理。我们的 EEG 数据显示，关于非相干视频的信息是由前馈相关的伽马活动编码的，而关于相干视频的信息是由反馈相关的阿尔法活动编码的，这表明整合确实是由节律活动介导的。我们的 fMRI 数据确定了场景选择性皮质和人类中颞复合体 (hMT) 作为这种反馈的可能来源。对我们的 EEG 和 fMRI 数据进行分析组合，进一步表明，在阿尔法波段的反馈相关表示形式塑造了皮质中视觉处理的最早阶段。总的来说，我们的研究结果表明，连贯视觉体验的构建依赖于完整贯穿视觉层次结构的皮质反馈节律。
