Department of Psychology, Center for Integrative and Cognitive Neuroscience, Vanderbilt Vision Research Center, Vanderbilt University, Nashville, TN 37240-7817, USA.
J Exp Psychol Learn Mem Cogn. 2012 Sep;38(5):1206-20. doi: 10.1037/a0027389. Epub 2012 Mar 12.
A defining characteristic of visual working memory is its limited capacity. This means that it is crucial to maintain only the most relevant information in visual working memory. However, empirical research is mixed as to whether it is possible to selectively maintain a subset of the information previously encoded into visual working memory. Here we examined the ability of participants to use cues to either forget or remember a subset of the information already stored in visual working memory. In Experiment 1, participants were cued to either forget or remember 1 of 2 groups of colored squares during a change-detection task. We found that both types of cues aided performance in the visual working memory task but that observers benefited more from a cue to remember than a cue to forget a subset of the objects. In Experiment 2, we show that the previous findings, which indicated that directed-forgetting cues are ineffective, were likely due to the presence of invalid cues that appeared to cause observers to disregard such cues as unreliable. In Experiment 3, we recorded event-related potentials and show that an electrophysiological index of focused maintenance is elicited by cues that indicate which subset of information in visual working memory needs to be remembered, ruling out alternative explanations of the behavioral effects of retention-interval cues. The present findings demonstrate that observers can focus maintenance mechanisms on specific objects in visual working memory based on cues indicating future task relevance.
视觉工作记忆的一个定义特征是其有限的容量。这意味着在视觉工作记忆中保持最相关的信息至关重要。然而，关于是否有可能有选择地保持之前编码到视觉工作记忆中的信息的一个子集，实证研究结果不一。在这里，我们研究了参与者使用提示来忘记或记住视觉工作记忆中已经存储的信息子集的能力。在实验 1 中，参与者在变化检测任务中被提示忘记或记住 2 组彩色方块中的 1 组。我们发现，这两种类型的提示都有助于视觉工作记忆任务的表现，但观察者从记住提示中受益更多，而不是从忘记提示中受益更多。在实验 2 中，我们表明，先前的发现表明定向遗忘提示无效，这可能是由于存在无效提示，这些提示似乎导致观察者认为这些提示不可靠。在实验 3 中，我们记录了事件相关电位，并表明，当提示指示需要记住视觉工作记忆中的哪个信息子集时，会引发聚焦维持的电生理指数，排除了保留间隔提示对行为效应的替代解释。这些发现表明，观察者可以根据指示未来任务相关性的提示，将维持机制集中在视觉工作记忆中的特定对象上。
