Department of Psychological and Brain Sciences, The Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
J Cogn Neurosci. 2011 May;23(5):1198-204. doi: 10.1162/jocn.2010.21503. Epub 2010 Apr 30.
Attention is a neurocognitive mechanism that selects task-relevant sensory or mnemonic information to achieve current behavioral goals. Attentional modulation of cortical activity has been observed when attention is directed to specific locations, features, or objects. However, little is known about how high-level categorization task set modulates perceptual representations. In the current study, observers categorized faces by gender (male vs. female) or race (Asian vs. White). Each face was perceptually ambiguous in both dimensions, such that categorization of one dimension demanded selective attention to task-relevant information within the face. We used multivoxel pattern classification to show that task-specific modulations evoke reliably distinct spatial patterns of activity within three face-selective cortical regions (right fusiform face area and bilateral occipital face areas). This result suggests that patterns of activity in these regions reflect not only stimulus-specific (i.e., faces vs. houses) responses but also task-specific (i.e., race vs. gender) attentional modulation. Furthermore, exploratory whole-brain multivoxel pattern classification (using a searchlight procedure) revealed a network of dorsal fronto-parietal regions (left middle frontal gyrus and left inferior and superior parietal lobule) that also exhibit distinct patterns for the two task sets, suggesting that these regions may represent abstract goals during high-level categorization tasks.
注意力是一种神经认知机制，它选择与任务相关的感觉或记忆信息，以实现当前的行为目标。当注意力指向特定的位置、特征或对象时，已经观察到注意力对皮质活动的调节。然而，对于高级分类任务集如何调节感知表示，人们知之甚少。在当前的研究中，观察者根据性别（男性与女性）或种族（亚洲人与白人）对人脸进行分类。每个面孔在两个维度上都是知觉上的模糊的，因此一个维度的分类需要选择性地注意面孔内与任务相关的信息。我们使用多体素模式分类来表明，特定任务的调节会在三个面部选择性皮质区域（右侧梭状回面部区和双侧枕叶面部区）内引起可靠的、不同的活动空间模式。这一结果表明，这些区域的活动模式不仅反映了刺激特异性（即面孔与房屋）的反应，还反映了任务特异性（即种族与性别）的注意力调节。此外，探索性的全脑多体素模式分类（使用搜索灯程序）揭示了一个背侧额顶叶区域的网络（左中央额回和左顶叶下叶和上叶），这两个任务集也表现出不同的模式，这表明这些区域可能在高级分类任务中代表抽象的目标。
