Visual working memory has been defined as a system of limited capacity that enables the maintenance and manipulation of visual information. However, some perceptual features like Gestalt grouping could improve visual working memory effectiveness. In two different experiments, we aimed to explore how the presence of elements grouped by color similarity affects the change detection performance of both, grouped and non-grouped items. We combined a change detection task with a retrocue paradigm in which a six item array had to be remembered. An always valid, variable-delay retrocue appeared in some trials during the retention interval, either after 100 ms (iconic-trace period) or 1400 ms (working memory period), signaling the location of the probe. The results indicated that similarity grouping biased the information entered into the visual working memory, improving change detection accuracy only for previously grouped probes, but hindering change detection for non-grouped probes in certain conditions (Exp. 1). However, this bottom-up automatic encoding bias was overridden when participants were explicitly instructed to ignore grouped items as they were irrelevant for the task (Exp. 2).

视觉工作记忆被定义为一个容量有限的系统，能够维护和操作视觉信息。然而，一些感知特征（例如格式塔分组）可以提高视觉工作记忆的有效性。在两个不同的实验中，我们旨在探索按颜色相似性分组的元素的存在如何影响分组和非分组项目的变化检测性能。我们将变化检测任务与回溯范例相结合，其中必须记住六项数组。在一些试验中，在保留间隔期间（100 毫秒（标志性跟踪周期）或 1400 毫秒（工作记忆周期）后）会出现始终有效的可变延迟回溯，指示探针的位置。结果表明，相似性分组使输入视觉工作记忆的信息产生偏差，仅提高了先前分组探针的变化检测准确性，但在某些条件下阻碍了未分组探针的变化检测（实验1）。然而，当参与者被明确指示忽略与任务无关的分组项目时，这种自下而上的自动编码偏差被覆盖（实验 2）。