Retinotopic Patterns of Correlated Fluctuations in Visual Cortex Reflect the Dynamics of Spontaneous Perceptual Suppression
Retinotopic Patterns of Correlated Fluctuations in Visual Cortex Reflect the Dynamics of Spontaneous Perceptual Suppression
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DOI：
10.1523/jneurosci.3388-12.2013
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发表时间：
2013-01-30
影响因子：
5.3
通讯作者：
Heeger, David J.
中科院分区：
文献类型：
--
作者：
Donner, Tobias H.;Sagi, Dov;Heeger, David J.
在观看某些刺激时，面对不断的输入，感知会自发地发生变化。例如，在“运动致盲”（MIB）过程中，一个小的突出目标在被移动的面具包围时自发地消失并重新出现。这种双稳态知觉现象的模型假定在视觉皮层层次的多个阶段神经元活动的自发波动。我们使用功能磁共振成像将人类视觉皮层V1到V4区域的相关活动波动与MIB目标消失的动态（速率和持续时间）联系起来。我们计算了与MIB目标和掩膜对应的多个视网膜异位亚区fMRI活动时间序列之间的相关性。时间相关性矩阵的线性分解揭示了活动波动的空间模式，无论这些模式是否与目标消失的行为报告时间锁定。在MIB期间主导活动波动的空间模式在空间上是非特异性的，由所有子区域共享，但没有反映感知的动态。相比之下，在V4中，与MIB消失速率相关的波动是针对目标子区域的视网膜特异性波动，而在V1中，与MIB消失状态持续时间相关的波动是针对目标特异性的。以前没有通过平均活动时间锁定到MIB消失的行为报告来确定V1中特定目标的波动。我们的研究结果表明，不同层次的视觉皮层通过不同的机制塑造感知的动态，这在不同的自发皮层活动波动的空间模式中是明显的。
While viewing certain stimuli, perception changes spontaneously in the face of constant input. For example, during "motion-induced blindness" (MIB), a small salient target spontaneously disappears and reappears when surrounded by a moving mask. Models of such bistable perceptual phenomena posit spontaneous fluctuations in neuronal activity throughout multiple stages of the visual cortical hierarchy. We used fMRI to link correlated activity fluctuations across human visual cortical areas V1 through V4 to the dynamics (rate and duration) of MIB target disappearance. We computed the correlations between the time series of fMRI activity in multiple retinotopic subregions corresponding to MIB target and mask. Linear decomposition of the matrix of temporal correlations revealed spatial patterns of activity fluctuations, regardless of whether or not these were time-locked to behavioral reports of target disappearance. The spatial pattern that dominated the activity fluctuations during MIB was spatially nonspecific, shared by all subregions, but did not reflect the dynamics of perception. By contrast, the fluctuations associated with the rate of MIB disappearance were retinotopically specific for the target subregion in V4, and the fluctuations associated with the duration of MIB disappearance states were target-specific in V1. Target-specific fluctuations in V1 have not previously been identified by averaging activity time-locked to behavioral reports of MIB disappearance. Our results suggest that different levels of the visual cortical hierarchy shape the dynamics of perception via distinct mechanisms, which are evident in distinct spatial patterns of spontaneous cortical activity fluctuations.