Neural correlates of sustained spatial attention in human early visual cortex
Neural correlates of sustained spatial attention in human early visual cortex
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DOI：
10.1152/jn.00677.2006
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发表时间：
2007-01-01
影响因子：
2.5
通讯作者：
Heeger, David J.
中科院分区：
文献类型：
--
作者：
Silver, Michael A.;Ress, David;Heeger, David J.
注意力被认为是通过自上而下的注意力信号来调节视觉皮层的活动，从而增强在关注位置的感知表现。在这里，我们表明，在没有视觉刺激的情况下，在维持注意力的过程中，早期视觉皮层的活动是持续的。我们使用功能性磁共振成像（fMRI）来测量视觉皮层的活动，而人类受试者进行视觉检测任务，其中一个可变的持续时间延迟期之前的目标介绍。部分皮质区V1，V2和V3代表的出席部分的视野表现出持续增加的活动在整个延迟期。这些皮层区域的部分代表周边，无人看管的部分视野显示持续减少的活动。这些数据很好地拟合了一个模型，该模型假设持续的神经活动在一段时间内的振幅是恒定的，该时间段等于每次试验的实际延迟期。这些结果表明，持续的注意力反应存在于早期视觉皮层（包括初级视觉皮层），在没有视觉刺激，这些反应与视觉空间的注意力在空间和时间域的分配。
Attention is thought to enhance perceptual performance at attended locations through top-down attention signals that modulate activity in visual cortex. Here, we show that activity in early visual cortex is sustained during maintenance of attention in the absence of visual stimulation. We used functional magnetic resonance imaging (fMRI) to measure activity in visual cortex while human subjects performed a visual detection task in which a variable-duration delay period preceded target presentation. Portions of cortical areas V1, V2, and V3 representing the attended part of the visual field exhibited sustained increases in activity throughout the delay period. Portions of these cortical areas representing peripheral, unattended parts of the visual field displayed sustained decreases in activity. The data were well fit by a model that assumed the sustained neural activity was constant in amplitude over a time period equal to that of the actual delay period for each trial. These results demonstrate that sustained attention responses are present in early visual cortex ( including primary visual cortex), in the absence of a visual stimulus, and that these responses correlate with the allocation of visuospatial attention in both the spatial and temporal domains.