Golomb Julie D, Chun Marvin M, Mazer James A
Interdepartmental Neuroscience Program, Department of Psychology, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
J Neurosci. 2008 Oct 15;28(42):10654-62. doi: 10.1523/JNEUROSCI.2525-08.2008.
Visual processing can be facilitated by covert attention at behaviorally relevant locations. If the eyes move while a location in the visual field is facilitated, what happens to the internal representation of the attended location? With each eye movement, the retinotopic (eye-centered) coordinates of the attended location change while the spatiotopic (world-centered) coordinates remain stable. To investigate whether the neural substrates of spatial attention reside in retinotopically and/or spatiotopically organized maps, we used a novel gaze-contingent behavioral paradigm that probed spatial attention at various times after eye movements. When task demands required maintaining a spatiotopic representation after the eye movement, we found facilitation at the retinotopic location of the spatial cue for 100-200 ms after the saccade, although this location had no behavioral significance. This task-irrelevant retinotopic representation dominated immediately after the saccade, whereas at later delays, the task-relevant spatiotopic representation prevailed. However, when task demands required maintaining the cue in retinotopic coordinates, a strong retinotopic benefit persisted long after the saccade, and there was no evidence of spatiotopic facilitation. These data suggest that the cortical and subcortical substrates of spatial attention primarily reside in retinotopically organized maps that must be dynamically updated to compensate for eye movements when behavioral demands require a spatiotopic representation of attention. Our conclusion is that the visual system's native or low-level representation of endogenously maintained spatial attention is retinotopic, and remapping of attention to spatiotopic coordinates occurs slowly and only when behaviorally necessary.
在行为相关位置的隐蔽注意力可以促进视觉处理。如果在视野中的某个位置得到促进时眼睛发生移动，那么被关注位置的内部表征会发生什么变化？每次眼睛移动时，被关注位置的视网膜拓扑（以眼睛为中心）坐标会发生变化，而空间拓扑（以世界为中心）坐标保持稳定。为了研究空间注意力的神经基质是否存在于视网膜拓扑和/或空间拓扑组织的图谱中，我们使用了一种新颖的注视相关行为范式，该范式在眼睛移动后的不同时间探测空间注意力。当任务要求在眼睛移动后维持空间拓扑表征时，我们发现在扫视后100 - 200毫秒，空间线索的视网膜拓扑位置出现促进作用，尽管这个位置没有行为意义。这种与任务无关的视网膜拓扑表征在扫视后立即占主导地位，而在稍后的延迟阶段，与任务相关的空间拓扑表征占上风。然而，当任务要求在视网膜拓扑坐标中维持线索时，强烈的视网膜拓扑优势在扫视后很长时间持续存在，并且没有空间拓扑促进的证据。这些数据表明，空间注意力的皮质和皮质下基质主要存在于视网膜拓扑组织的图谱中，当行为需求需要注意力的空间拓扑表征时，这些图谱必须动态更新以补偿眼睛移动。我们的结论是，视觉系统内源性维持的空间注意力的原生或低级表征是视网膜拓扑的，并且只有在行为必要时，注意力向空间拓扑坐标的重新映射才会缓慢发生。
