Updating of the visual representation in monkey striate and extrastriate cortex during saccades
Updating of the visual representation in monkey striate and extrastriate cortex during saccades
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DOI：
10.1073/pnas.052379899
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发表时间：
2002-03-19
影响因子：
11.1
通讯作者：
Colby, CL
中科院分区：
文献类型：
--
作者：
Nakamura, K;Colby, CL
外侧顶内区、额叶眼区和上级丘的神经元表现出一种称为重映射的活动模式。当一个突出的视觉刺激是在扫视之前不久，该刺激的表示更新，或重新映射，在眼睛运动的时间。这种更新大概是基于眼球运动命令的必然放电。为了研究视觉区域是否也表现出重新映射，我们记录了猴子执行扫视任务时纹外和纹状皮质中的单个神经元。在扫视的时候，视觉刺激在扫视之前（旧RF）或扫视之后（新RF）在神经元的感受野（RF）所占据的位置处闪现。超过一半（52%）的V3A神经元对新RF中闪现的刺激做出反应，即使刺激在扫视之前已经消失。这些神经元会对眼跳带入RF的闪光刺激的痕迹做出反应。在16%的V3A神经元中，重新映射的活动甚至在扫视开始之前就开始了。在视觉层次的早期阶段也观察到重映射，包括V3和V2区域。在这些早期阶段，表现出重新映射的神经元的比例下降，并且相对于扫视开始，重新映射活动的潜伏期增加。纹状皮质的重映射非常罕见。这些结果表明，纹外视区参与了重映射的过程。
Neurons in the lateral intraparietal area, frontal eye field, and superior colliculus exhibit a pattern of activity known as remapping. When a salient visual stimulus is presented shortly before a saccade, the representation of that stimulus is updated, or remapped, at the time of the eye movement. This updating is presumably based on a corollary discharge of the eye movement command. To investigate whether visual areas also exhibit remapping, we recorded from single neurons in extrastriate and striate cortex while monkeys performed a saccade task. Around the time of the saccade, a visual stimulus was flashed either at the location occupied by the neuron's receptive field (RF) before the saccade (old RF) or at the location occupied by it after the saccade (new RF). More than half (52%) of V3A neurons responded to a stimulus flashed in the new RF even though the stimulus had already disappeared before the saccade. These neurons responded to a trace of the flashed stimulus brought into the RF by the saccade. In 16% of V3A neurons, remapped activity began even before saccade onset. Remapping also was observed at earlier stages of the visual hierarchy, including in areas V3 and V2. At these earlier stages, the proportion of neurons that exhibited remapping decreased, and the latency of remapped activity increased relative to saccade onset. Remapping was very rare in striate cortex. These results indicate that extrastriate visual areas are involved in the process of remapping.