Topographic maps of visual spatial attention in human parietal cortex
Topographic maps of visual spatial attention in human parietal cortex
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DOI：
10.1152/jn.01316.2004
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发表时间：
2005-08-01
影响因子：
2.5
通讯作者：
Heeger, DJ
中科院分区：
文献类型：
--
作者：
Silver, MA;Ress, D;Heeger, DJ
功能性磁共振成像（fMRI）被用来测量人类顶叶皮层的活动，在执行视觉检测任务，其中注意力的焦点系统地穿过视野。重要的是，所有试验中的刺激都是相同的（除了在完全随机选择的目标位置中轻微的对比度变化），而只有提示位置不同。在后顶叶皮层观察到活动的行波，这与在没有眼球运动的情况下内隐注意的转移一致。每个体素中fMRI信号的时间相位指示相应的视野位置。顶叶皮层的扁平化表示的时间阶段的分布可视化显示至少有两个不同的地形组织的皮质区内的顶内沟（IPS），每个代表对侧视野。基于这种地形组织，我们提出了两个皮层区域，我们称之为IPS1和IPS2，以指示它们在IPS中的位置。该命名法对于猴脑中已确立的皮质区可能的同源性是中性的。与早期视觉区域相比，这两个拟议的皮层区域对被动视觉刺激的反应相对较小。这些结果为顶叶皮层的多地形图提供了证据。
Functional magnetic resonance imaging ( fMRI) was used to measure activity in human parietal cortex during performance of a visual detection task in which the focus of attention systematically traversed the visual field. Critically, the stimuli were identical on all trials ( except for slight contrast changes in a fully randomized selection of the target locations) whereas only the cued location varied. Traveling waves of activity were observed in posterior parietal cortex consistent with shifts in covert attention in the absence of eye movements. The temporal phase of the fMRI signal in each voxel indicated the corresponding visual field location. Visualization of the distribution of temporal phases on a flattened representation of parietal cortex revealed at least two distinct topographically organized cortical areas within the intraparietal sulcus (IPS), each representing the contralateral visual field. Two cortical areas were proposed based on this topographic organization, which we refer to as IPS1 and IPS2 to indicate their locations within the IPS. This nomenclature is neutral with respect to possible homologies with well-established cortical areas in the monkey brain. The two proposed cortical areas exhibited relatively little response to passive visual stimulation in comparison with early visual areas. These results provide evidence for multiple topographic maps in human parietal cortex.