Faculty of Education, Hokkaido University, Sapporo, 060-0811, Japan.
Brain Res. 2011 Jul 5;1399:49-58. doi: 10.1016/j.brainres.2011.05.016. Epub 2011 May 14.
It has been proposed that the most fundamental units of attentional selection are "objects" that are grouped according to Gestalt factors such as similarity or connectedness. Previous studies using event-related potentials (ERPs) have shown that object-based attention is associated with modulations of the visual-evoked N1 component, which reflects an early cortical mechanism that is shared with spatial attention. However, these studies only examined the case of perceptually continuous objects. The present study examined the case of separate objects that are grouped according to feature similarity (color, shape) by indexing lateralized potentials at posterior sites in a sustained-attention task that involved bilateral stimulus arrays. A behavioral object effect was found only for task-relevant shape similarity. Electrophysiological results indicated that attention was guided to the task-irrelevant side of the visual field due to achromatic-color similarity in N1 (155-205 ms post-stimulus) and early N2 (210-260 ms) and due to shape similarity in early N2 and late N2 (280-400 ms) latency ranges. These results are discussed in terms of selection mechanisms and object/group representations.
有人提出，注意力选择的最基本单位是“对象”，这些对象根据相似性或连接性等格式塔因素进行分组。先前使用事件相关电位 (ERP) 的研究表明，基于对象的注意力与视觉诱发的 N1 成分的调制有关，该成分反映了与空间注意力共享的早期皮质机制。然而，这些研究仅检查了感知连续对象的情况。本研究通过在涉及双侧刺激阵列的持续注意力任务中在后部位置索引偏侧化电位，检查了根据特征相似性（颜色、形状）分组的分离对象的情况。仅在任务相关的形状相似性上发现了行为对象效应。电生理结果表明，由于 N1（刺激后 155-205 毫秒）和早期 N2（210-260 毫秒）中的非彩色相似性以及早期 N2 和晚期 N2（280-400 毫秒）潜伏期范围内的形状相似性，注意力被引导到视野的非任务相关侧。这些结果是根据选择机制和对象/组表示来讨论的。
