Pre-target activity in visual cortex predicts behavioral performance on spatial and feature attention tasks
Pre-target activity in visual cortex predicts behavioral performance on spatial and feature attention tasks
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DOI：
10.1016/j.brainres.2005.09.068
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发表时间：
2006-03-29
期刊：
影响因子：
2.9
通讯作者：
Manqun, GR
中科院分区：
文献类型：
--
作者：
Giesbrecht, B;Weissman, DH;Manqun, GR
对人类和猴子的生理研究表明，为了响应注意指令，编码预期刺激属性的感觉皮层区域在刺激到来之前表现出神经活动的增加。选择性视觉注意力模型认为，活动的增加使注意力集中的刺激比分散注意力的刺激具有处理优势。在这里，我们通过使用功能磁共振成像来记录提示自愿定向任务期间的人类大脑活动，来测试这一观点的两个关键预测。首先，我们测试了在提示空间和提示特征注意期间是否观察到刺激前调制。其次，我们测试了刺激前调节的幅度是否可以预测行为表现。我们的结果表明，线索触发的对具有特定空间或非空间特征的目标的期望会激活对这些特征有选择性的视觉皮层区域。此外，线索触发调节的幅度与行为测量相关，因此那些表现出相对较大的刺激前活动调节的受试者在行为任务中表现更好。这些发现支持这样的观点，即自上而下的控制系统会偏向感觉皮层的活动，以有利于预期目标特征的处理，并且这种偏向与行为有关。 (c) 2005 Elsevier B.V. 保留所有权利。
Physiological studies in humans and monkeys have revealed that, in response to an instruction to attend, areas of sensory cortex that code the attributes of the expected stimulus exhibit increases in neural activity prior to the arrival of the stimulus. Models of selective visual attention posit that these increases in activity give attended stimuli a processing advantage over distracting stimuli. Here, we test two key predictions of this view by using functional magnetic resonance imaging to record human brain activity during a cued voluntary orienting task. First, we tested whether pre-stimulus modulations are observed during both cued spatial and cued feature attention. Secondly, we tested whether the magnitude of pre-stimulus modulations predicts behavioral performance. Our results indicate that cue-triggered expectation of targets with particular spatial or nonspatial features activates areas of the visual cortex selective for these features. Furthermore, the magnitude of the cue-triggered modulations correlated with behavioral measures, such that those subjects who exhibited relatively large pre-stimulus modulations of activity performed better on the behavioral task. These findings support the view that top-down control systems bias activity in sensory cortices to favor the processing of expected target features and that this bias is related to behavior. (c) 2005 Elsevier B.V. All rights reserved.