Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff, CF24 4HQ, Wales, UK.
Neuroimage. 2018 May 15;172:228-238. doi: 10.1016/j.neuroimage.2018.01.062. Epub 2018 Feb 3.
Retrieval orientations are memory states that bias retrieval towards specific memory contents. Many neuroimaging studies have examined the influence of retrieval orientations on stimulus processing, but very little direct evidence exists regarding the ongoing maintenance of orientations themselves. Participants completed two memory tasks with different retrieval goals. ERPs were time-locked to a pre-stimulus fixation asterisk and contrasted according to retrieval goals. Pre-stimulus ERPs elicited during the two retrieval tasks diverged at frontal electrode sites. These differences onset early and were sustained throughout the fixation-stimulus interval. The functional and spatiotemporal characteristics of this ERP effect comprise the first direct electrophysiological evidence of the ongoing maintenance of retrieval orientations throughout a task. Moreover, this effect was eliminated in participants who performed a stroop task prior to the memory tests, indicating that reserves of cognitive control play an important role in the maintenance of retrieval orientations throughout memory tasks.
提取定向是一种记忆状态，它使提取偏向于特定的记忆内容。许多神经影像学研究都考察了提取定向对刺激加工的影响，但关于定向本身的持续维持，直接证据非常少。参与者完成了两个具有不同提取目标的记忆任务。ERP 与预刺激注视星号时间锁定，并根据提取目标进行对比。在两个提取任务期间诱发的预刺激 ERP 在额部电极位置上存在差异。这些差异很早就出现，并在整个注视-刺激间隔内持续存在。该 ERP 效应的功能和时空特征构成了直接电生理证据，证明在整个任务过程中提取定向的持续维持。此外，在记忆测试之前执行 Stroop 任务的参与者中，这种效应被消除了，这表明认知控制的储备在整个记忆任务中维持提取定向起着重要作用。
