Visual working memory load disrupts the space-based attentional guidance of target selection
Visual working memory load disrupts the space-based attentional guidance of target selection
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DOI：
10.1111/bjop.12323
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发表时间：
2019-05-01
影响因子：
4
通讯作者：
Eimer, Martin
中科院分区：
文献类型：
--
作者：
Berggren, Nick;Eimer, Martin
在视觉搜索过程中，目标对象的选择是由目标定义特征（注意模板）的存储表示来指导的。人们普遍认为，这样的模板保持在视觉工作记忆（WM），但这一假设的经验证据仍然是不确定的。在这里，我们测试是否保留非空间对象的功能（形状）在WM干扰注意力的目标选择过程中的并发搜索任务，需要空间模板的目标位置。参与者记住一个形状（低WM负载）或四个形状（高WM负载）在一个样本显示在一个保留期。在一些试验中，他们将它们与随后的记忆测试显示相匹配。在其他试验中，替代地呈现了包括上视野或下视野中的两个横向条的搜索显示，并且参与者报告了由其位置定义的目标条的方向（例如，左上或右下）。为了评估在低和高工作记忆负荷下的注意控制效率，记录EEG，并测量N2pc作为注意目标选择的标记。目标N2PC组件强烈延迟时，并发WM负载高，这表明，持有多个对象的形状在WM的竞争与同时保留的空间注意力模板的目标位置。这些观察结果提供了新的电生理证据，这些模板保持在WM，也挑战的建议，空间和非空间的内容表示在单独的独立的视觉WM商店。
During visual search, the selection of target objects is guided by stored representations of target-defining features (attentional templates). It is commonly believed that such templates are maintained in visual working memory (WM), but empirical evidence for this assumption remains inconclusive. Here, we tested whether retaining non-spatial object features (shapes) in WM interferes with attentional target selection processes in a concurrent search task that required spatial templates for target locations. Participants memorized one shape (low WM load) or four shapes (high WM load) in a sample display during a retention period. On some trials, they matched them to a subsequent memory test display. On other trials, a search display including two lateral bars in the upper or lower visual field was presented instead, and participants reported the orientation of target bars that were defined by their location (e.g., upper left or lower right). To assess the efficiency of attentional control under low and high WM load, EEG was recorded and the N2pc was measured as a marker of attentional target selection. Target N2pc components were strongly delayed when concurrent WM load was high, indicating that holding multiple object shapes in WM competes with the simultaneous retention of spatial attentional templates for target locations. These observations provide new electrophysiological evidence that such templates are maintained in WM, and also challenge suggestions that spatial and non-spatial contents are represented in separate independent visual WM stores.