Processing efficiency of divided spatial attention mechanisms in human visual cortex
Processing efficiency of divided spatial attention mechanisms in human visual cortex
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DOI：
10.1523/jneurosci.2647-05.2005
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发表时间：
2005-10-12
影响因子：
5.3
通讯作者：
Somers, DC
中科院分区：
文献类型：
--
作者：
McMains, SA;Somers, DC
许多视觉任务需要将注意力部署到多个对象或位置。我们使用功能性磁共振成像和行为实验来研究两种假定的注意机制的相对处理效率：“变焦透镜”和“多聚光灯”。研究了两个关键问题：（1）与变焦透镜相比，将聚光灯分成多个焦点是否会产生降低注意力功效的开销成本;（2）与变焦透镜相比，将聚光灯分成多个焦点是否会节省注意力资源，从而提供相对于变焦透镜的益处，否则这些注意力资源将被引导到与任务无关的刺激上？对于这两种机制，出席多个对象的位置在一个单一的位置降低了处理效率，导致行为表现下降和降低血氧水平依赖（BOLD）信号注意力调节。当这两种机制涉及到多个物体在同一空间范围内，多聚光灯机制，忽略干预刺激，产生了更好的性能和更高的BOLD信号。当这两种机制处理相同数量的刺激时，分开聚光灯既不会损害表现，也不会减少枕叶皮层的BOLD信号。多聚光灯机制令人惊讶的效率支持新兴的观点，即空间注意力很容易部署在不同的空间配置。
Many visual tasks require deployment of attention to multiple objects or locations. We used functional magnetic resonance imaging and behavioral experiments to investigate the relative processing efficiency of two putative attentional mechanisms for performing such tasks: the "zoom lens" and "multiple spotlights." Two key questions were investigated: ( 1) does splitting the spotlight into multiple foci incur an overhead cost that diminishes the efficacy of attention compared with the zoom lens, and ( 2) does splitting the spotlight provide a benefit relative to the zoom lens by conserving attention resources that otherwise would be directed to task irrelevant stimuli? For both mechanisms, attending to multiple object locations decreased processing efficiency at a single location, resulting in both decreased behavioral performance and decreased blood oxygenation level-dependent (BOLD) signal attentional modulation. When the two mechanisms attended to multiple objects across the same spatial extent, the multiple spotlight mechanism, which ignores intervening stimuli, yielded better performance and higher BOLD signal. When the two mechanisms processed the same number of stimuli, splitting the spotlight neither impaired performance nor diminished BOLD signal in occipital cortex. The surprising efficiency of the multiple spotlight mechanism supports the emerging view that spatial attention is easily deployed in a diverse range of spatial configurations.