ABSTRACT

Recent research has shown that providing a cue to selectively forget one subset of previously learned facts may result in specific forgetting of this information. Behavioral evidence suggests that this selective directed forgetting effect relies on executive control and is a direct consequence of active, rather than passive, mechanisms. To date, however, no previous research has addressed the neural underpinnings of selective directed forgetting. Since the lateral prefrontal cortex is thought to mediate motivated forgetting by exerting top-down control over the brain structures that underpin memory representations, the present study aimed to test the hypothesis that selective directed forgetting is prefrontally driven. Specifically, we used transcranial direct current stimulation to disrupt activity in the dorsolateral prefrontal cortex, using a stimulation protocol that has already been shown to be effective in this regard. Our results reveal that, in contrast to sham stimulation, real stimulation abolished selective directed forgetting. Additionally, real stimulation hindered performance in an updating working memory task thought to recruit the lateral prefrontal cortex. These findings, complementing others obtained with a variety of memory control tasks, support the hypothesis that memory downregulation is achieved by control processes mediated by the right lateral prefrontal cortex.

摘要

最近的研究表明，提供提示以选择性地忘记先前学习的事实的一个子集可能会导致对这些信息的特定遗忘。行为证据表明，这种选择性定向遗忘效应依赖于执行控制，是主动而非被动机制的直接结果。然而，迄今为止，之前的研究还没有解决选择性定向遗忘的神经基础。由于外侧前额叶皮层被认为通过对支撑记忆表征的大脑结构施加自上而下的控制来调节有动机的遗忘，因此本研究旨在检验选择性定向遗忘是由前额叶驱动的假设。具体来说，我们使用经颅直流电刺激来破坏背外侧前额叶皮层的活动，使用已被证明在这方面有效的刺激方案。我们的结果表明，与虚假刺激相比，真实刺激消除了选择性定向遗忘。此外，真正的刺激阻碍了更新工作记忆任务的表现，该任务被认为可以招募外侧前额叶皮层。这些发现与通过各种记忆控制任务获得的其他发现相辅相成，支持以下假设：记忆下调是由右侧前额叶皮层介导的控制过程实现的。真正的刺激阻碍了更新工作记忆任务的表现，该任务被认为可以招募外侧前额叶皮层。这些发现与通过各种记忆控制任务获得的其他发现相辅相成，支持以下假设：记忆下调是由右侧前额叶皮层介导的控制过程实现的。真正的刺激阻碍了更新工作记忆任务的表现，该任务被认为可以招募外侧前额叶皮层。这些发现与通过各种记忆控制任务获得的其他发现相辅相成，支持以下假设：记忆下调是由右侧前额叶皮层介导的控制过程实现的。