Emrich Stephen M, Ferber Susanne
Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, USA.
J Vis. 2012 Apr 20;12(4):12. doi: 10.1167/12.4.12.
When faced with maintaining multiple objects in visual working memory, item information must be bound to the correct object in order to be correctly recalled. Sometimes, however, binding errors occur, and participants report the feature (e.g., color) of an unprobed, non-target item. In the present study, we examine whether the configuration of sample stimuli affects the proportion of these binding errors. The results demonstrate that participants mistakenly report the identity of the unprobed item (i.e., they make a non-target response) when sample items are presented close together in space, suggesting that binding errors can increase independent of increases in memory load. Moreover, the proportion of these non-target responses is linearly related to the distance between sample items, suggesting that these errors are spatially specific. Finally, presenting sample items sequentially decreases non-target responses, suggesting that reducing competition between sample stimuli reduces the number of binding errors. Importantly, these effects all occurred without increases in the amount of error in the memory representation. These results suggest that competition during encoding can account for some of the binding errors made during VWM recall.
当面临在视觉工作记忆中维持多个物体时，项目信息必须与正确的物体绑定，以便能够被正确回忆。然而，有时会出现绑定错误，参与者会报告未被探测的非目标项目的特征（如颜色）。在本研究中，我们考察样本刺激的配置是否会影响这些绑定错误的比例。结果表明，当样本项目在空间上彼此靠近呈现时，参与者会错误地报告未被探测项目的特征（即他们做出非目标反应），这表明绑定错误可能会在记忆负荷未增加的情况下增加。此外，这些非目标反应的比例与样本项目之间的距离呈线性关系，这表明这些错误具有空间特异性。最后，依次呈现样本项目会减少非目标反应，这表明减少样本刺激之间的竞争会减少绑定错误的数量。重要的是，所有这些效应都是在记忆表征的错误量没有增加的情况下出现的。这些结果表明，编码过程中的竞争可以解释视觉工作记忆回忆过程中出现的一些绑定错误。
