Spatial selection of features within perceived and remembered objects
Spatial selection of features within perceived and remembered objects
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DOI：
10.3389/neuro.09.006.2009
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发表时间：
2009-04-01
影响因子：
2.9
通讯作者：
Nobre, Anna C.
中科院分区：
文献类型：
--
作者：
Astle, Duncan E.;Scerif, Gaia;Nobre, Anna C.
我们对视觉世界的表征可以通过灵活依赖于任务目标的空间特定注意力偏差来调节。我们比较了在感知对象和记忆对象中搜索与任务相关的特征。在搜索感知输入时，选定的与任务相关和被抑制的与任务无关的特征会引发对比的时空 ERP 效应，尽管它们在感知上是相同的。当参与者搜索记忆阵列时也是如此，这表明记忆保留了原始感知输入的空间组织，并且这种表示可以以空间特定的方式进行调节。然而，与搜索感知对象相比，在搜索记忆对象时，与任务相关的选择和与任务无关的抑制效应具有相反的极性。我们认为，这一令人惊讶的结果源于存储在视觉短期记忆中时基于特征和基于对象的表示的本质。存储时，特征被集成到对象中，这意味着空间特定的选择机制必须针对对象而不是特定的特征级表示进行操作。
Our representation of the visual world can be modulated by spatially specific attentional biases that depend flexibly on task goals. We compared searching for task-relevant features in perceived versus remembered objects. When searching perceptual input, selected task-relevant and suppressed task-irrelevant features elicited contrasting spatiotopic ERP effects, despite them being perceptually identical. This was also true when participants searched a memory array, suggesting that memory had retained the spatial organization of the original perceptual input and that this representation could be modulated in a spatially specific fashion. However, task-relevant selection and task-irrelevant suppression effects were of the opposite polarity when searching remembered compared to perceived objects. We suggest that this surprising result stems from the nature of feature- and object-based representations when stored in visual short-term memory. When stored, features are integrated into objects, meaning that the spatially specific selection mechanisms must operate upon objects rather than specific feature-level representations.