Attending to Multiple Visual Streams: Interactions between Location-based and Category-based Attentional Selection
Attending to Multiple Visual Streams: Interactions between Location-based and Category-based Attentional Selection
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DOI：
10.1162/jocn.2009.21116
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发表时间：
2009-08-01
影响因子：
3.2
通讯作者：
Macaluso, Emiliano
中科院分区：
文献类型：
--
作者：
Fagioli, Sabrina;Macaluso, Emiliano
行为研究表明，受试者能够在不同位置的多个信息流之间分配注意力。然而，目前还不清楚在何种程度上观察到的成本反映了与空间注意力相关的过程，而不是由于同时监测多个刺激流而产生的更普遍的干扰。在这里，我们使用了析因设计，以解开相关的位置与类别为基础的选择过程中的功能磁共振成像。在所有条件下，参与者在每个半视野中呈现两个重叠的视觉刺激（红色形状和绿色形状）。在不同的区块中，受试者：（1）在一个半野中关注一个单一的刺激类别，红色形状或绿色形状;（2）在同一半野中关注两个刺激类别;（3）关注一个单一的刺激类别，但同时监测两个半野;或（4）在一个半野中关注一个刺激类别，另一个类别在相反的半野中。行为数据显示了在两个半野上划分空间注意力的预期成本，以及监测两个刺激类别与一个类别的成本。成像数据显示激活的背侧额顶叶网络，既用于划分空间注意力和监测多个刺激类别。然而，与行为数据不同的是，成像结果还显示了同一网络中基于位置和类别的注意力之间的显着相互作用。这表明额顶叶皮层参与了这两种选择性注意功能，仅仅增加任务难度不能解释这些过程的共定位。我们的结论是，在多流监测的条件下，额顶区控制的位置和类别为基础的注意选择。
Behavioral studies indicate that subjects are able to divide attention between multiple streams of information at different locations. However, it is still unclear to what extent the observed costs reflect processes specifically associated with spatial attention, versus more general interference due the concurrent monitoring of multiple streams of stimuli. Here we used a factorial design to disentangle the correlates of location-versus category-based selection processes during fMRI. In all conditions, participants were presented with two overlapping visual stimuli (red shapes and green shapes) in each hemifield. In different blocks, subjects either: (1) attended to one single stimulus category, red shapes or green shapes, in one hemifield; (2) attended to both stimulus categories in the same hemifield; (3) attended to one single stimulus category, but monitoring both hemifields at the same time; or (4) attended to one stimulus category in one hemifield, and the other category in the opposite hemifield. The behavioral data showed the expected costs of dividing spatial attention across the two hemifields, and the cost of monitoring two stimulus categories versus one category. The imaging data revealed activation of a dorsal fronto-parietal network, both for dividing spatial attention and for monitoring multiple stimulus categories. However, unlike behavioral data, the imaging results also showed a significant interaction between location- and category-based attention within the same network. This demonstrates that the fronto-parietal cortex engages in both of these selective attention functions, and that a mere increase in task difficulty cannot explain colocalization of these processes. We conclude that, under conditions of multiple streams monitoring, fronto-parietal regions control location- and category-based attentional selection.