How humans transform sensory information into decisions that steer purposeful behavior is a central question in psychology and neuroscience that is traditionally investigated during the sampling of external environmental signals. The decision-making framework of gradual information sampling toward a decision has also been proposed to apply when sampling internal sensory evidence from working memory. However, neural evidence for this proposal remains scarce. Here we show (using scalp EEG in male and female human volunteers) that sampling internal visual representations from working memory elicits a scalp EEG potential associated with gradual evidence accumulation—the central parietal positivity. Consistent with an evolving decision process, we show how this signal (1) scales with the time participants require to reach a decision about the cued memory content and (2) is amplified when having to decide among multiple contents in working memory. These results bring the electrophysiology of decision-making into the domain of working memory and suggest that variability in memory-guided behavior may be driven (at least in part) by variations in the sampling of our inner mental contents.

人类如何将感官信息转化为引导有目的行为的决策是心理学和神经科学的一个核心问题，传统上是在外部环境信号采样过程中进行研究的。在从工作记忆中采样内部感官证据时，还提出了针对决策的逐步信息采样的决策框架。然而，支持这一提议的神经证据仍然很少。在这里，我们（使用男性和女性人类志愿者的头皮脑电图）表明，从工作记忆中采样内部视觉表征会引发与逐渐证据积累相关的头皮脑电图电位 - 中央顶叶积极性。与不断发展的决策过程相一致，我们展示了该信号如何（1）随着参与者就提示记忆内容做出决定所需的时间而变化，以及（2）在必须在工作记忆中的多个内容中做出决定时被放大。这些结果将决策的电生理学带入工作记忆领域，并表明记忆引导行为的可变性可能（至少部分）是由我们内部心理内容采样的变化驱动的。