Contextual Feedback to Superficial Layers of V1.
Contextual Feedback to Superficial Layers of V1.
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DOI：
10.1016/j.cub.2015.08.057
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发表时间：
2015-10-19
期刊：
影响因子：
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通讯作者：
Yacoub E
中科院分区：
文献类型：
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作者：
Muckli L;De Martino F;Vizioli L;Petro LS;Smith FW;Ugurbil K;Goebel R;Yacoub E
神经元皮质回路包括前馈、侧向和反馈投射，每一种投射都终止于不同的皮层。在感觉系统中，前馈处理将信号从外部世界传输到大脑皮层，而反馈通路则向大脑对世界的推理发出信号。然而，每个大脑皮层区域内前馈、侧向和反馈输入的整合阻碍了反馈的研究，而且到目前为止，还没有一种技术分离出健康人体大脑皮层不同层的视觉场景信息的反馈。我们屏蔽了对V1皮层区域的前馈输入，并研究了剩余的内部加工。使用高分辨率功能脑成像(0.8 mm~3)和多体素模式信息技术，我们证明了在正常视觉刺激时，场景信息在中层达到峰值。相反，我们发现语境反馈信息在表层达到峰值。此外，我们发现，改变面具周围视觉场景的位置对V1浅层的反馈进行参数调制。我们的结果揭示了健康受试者在知觉过程中外部和内部视觉处理流的分层皮质组织。我们为预测编码和相干Infomax等理论反馈模型提供了经验支持，并揭示了高分辨率功能磁共振成像在亚毫米人类大脑皮层进行内部处理的潜力。高分辨率MRI显示非刺激性V1的功能信息模式，非刺激性V1接收皮层反馈信息至浅层，反馈至非刺激性V1浅层可预测视觉环境。发现视觉皮层V1的浅层在没有受到直接刺激时接受信息。该信息包含来自更高视觉区域的上下文反馈。这些数据为与预测编码的神经生物学相关的特定层皮质反馈提供了经验证据。
Neuronal cortical circuitry comprises feedforward, lateral, and feedback projections, each of which terminates in distinct cortical layers. In sensory systems, feedforward processing transmits signals from the external world into the cortex, whereas feedback pathways signal the brain’s inference of the world. However, the integration of feedforward, lateral, and feedback inputs within each cortical area impedes the investigation of feedback, and to date, no technique has isolated the feedback of visual scene information in distinct layers of healthy human cortex. We masked feedforward input to a region of V1 cortex and studied the remaining internal processing. Using high-resolution functional brain imaging (0.8 mm3) and multivoxel pattern information techniques, we demonstrate that during normal visual stimulation scene information peaks in mid-layers. Conversely, we found that contextual feedback information peaks in outer, superficial layers. Further, we found that shifting the position of the visual scene surrounding the mask parametrically modulates feedback in superficial layers of V1. Our results reveal the layered cortical organization of external versus internal visual processing streams during perception in healthy human subjects. We provide empirical support for theoretical feedback models such as predictive coding and coherent infomax and reveal the potential of high-resolution fMRI to access internal processing in sub-millimeter human cortex. High-resolution MRI shows functional information patterns in non-stimulated V1 Non-stimulated V1 receives cortical feedback information to superficial layers Feedback to non-stimulated V1 superficial layers is predictive of visual context Muckli et al. have discovered that the superficial layers of visual cortex V1 receive information when not directly stimulated. This information contains contextual feedback from higher visual areas. The data provide empirical evidence for layer-specific cortical feedback relevant for the neurobiology of predictive coding.