Representations of visual objects in working memory (WM) can be part-based or object-based, and we investigated whether this is determined by top-down control processes. Lateralised change detection tasks were employed where sample objects on one task-relevant side had to be memorized. Contralateral delay activity (CDA) components were measured during the retention period as electrophysiological markers of WM maintenance processes. In two critical task conditions, sample displays contained objects composed of two vertically aligned shapes. In the Parts task, test displays contained a single shape that had to be matched with either of the two sample shapes, encouraging the storage of part-based WM representations. In the Whole task, compound-shape objects shown at test had to be matched with memorized compound objects, which should facilitate the formation of object-based integrated WM representations. CDA amplitudes were significantly larger in the Parts task than in the Whole task, indicative of differences in effective WM load. This suggests that the two individual shapes were represented separately in the Parts task, whereas a single compound object was maintained in the Whole task. These results provide new evidence that changes in task goals can result in qualitative differences in the way that identical visual stimuli are represented in WM.

中文翻译：

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任务目标调节视觉工作记忆中基于零件的表示与基于对象的表示的激活。

视觉对象在工作内存（WM）中的表示可以是基于部分的或基于对象的，并且我们调查了这是否由自上而下的控制过程确定。采用横向变更检测任务，其中必须记住与任务相关的一侧的样本对象。在保留期内测量对侧延迟活动（CDA）组件作为WM维护过程的电生理指标。在两个关键任务条件下，示例显示包含由两个垂直对齐的形状组成的对象。在“零件”任务中，测试显示包含一个必须与两个样本形状之一匹配的形状，从而鼓励存储基于零件的WM表示形式。在整个任务中，测试中显示的复合形状对象必须与记忆的复合对象匹配，这应该有助于形成基于对象的集成WM表示形式。“零件”任务中的CDA幅度明显大于“整个”任务中的CDA幅度，表明有效WM负载有所不同。这表明在“零件”任务中分别表示了两个单独的形状，而在“整体”任务中维护了单个复合对象。这些结果提供了新的证据，证明任务目标的变化会导致在WM中表示相同视觉刺激的方式发生质的差异。而在整个任务中维护了一个复合对象。这些结果提供了新的证据，证明任务目标的变化会导致在WM中表示相同视觉刺激的方式发生质的差异。而在整个任务中维护了一个复合对象。这些结果提供了新的证据，证明任务目标的变化会导致在WM中表示相同视觉刺激的方式发生质的差异。