University of Illinois at Chicago, Chicago, Illinois, USA.
Brain Behav. 2021 Dec;11(12):e2368. doi: 10.1002/brb3.2368. Epub 2021 Nov 3.
Past work shows that processing information in relation to the self improves memory which is known as the self-reference effect in memory. Other work suggests that transcranial direct current stimulation (tDCS) can also improve memory. Given recent research on self-reference context memory effects (improved memory for contextual episodic details associated with self-referential processing), we were interested in examining the extent stimulation might increase the magnitude of the self-reference context memory effect. In this investigation, participants studied objects superimposed on different background scenes in either a self-reference or other-reference condition while receiving either active or sham stimulation to the dorsal medial prefrontal cortex (dmPFC), a cortical region known to support self-reference context memory effects. Participants then completed a memory test that assessed item memory (have you seen this object before?) and context memory (with which background scene was this object paired?). Results showed a self-reference context memory effect driven by enhanced memory for stimuli processed in the self-reference compared to the other-reference condition across all participants (regardless of stimulation condition). tDCS, however, had no effect on memory. Specifically, stimulation did not increase the magnitude of the self-reference context memory effect under active compared to sham stimulation. These results suggest that stimulation of the dmPFC at encoding may not add to the memory benefits induced by self-referential processing suggesting a boundary condition to tDCS effects on memory.
以往的研究表明，与自我相关的信息处理可以提高记忆，这在记忆中被称为自我参照效应。其他研究表明，经颅直流电刺激（tDCS）也可以改善记忆。鉴于最近关于自我参照语境记忆效应的研究（与自我参照处理相关的语境情节细节的记忆得到改善），我们有兴趣研究刺激是否可以增加自我参照语境记忆效应的幅度。在这项研究中，参与者在接受背内侧前额叶皮层（dmPFC）的主动或假刺激的情况下，在自我参照或其他参照条件下学习叠加在不同背景场景上的物体，该皮层区域已知支持自我参照语境记忆效应。然后，参与者完成了一项记忆测试，评估项目记忆（你以前见过这个物体吗？）和语境记忆（这个物体与哪个背景场景配对？）。结果显示，自我参照语境记忆效应是由与自我参照相比，在其他参照条件下处理的刺激的记忆增强驱动的所有参与者（无论刺激条件如何）。然而，tDCS 对记忆没有影响。具体来说，与假刺激相比，在主动刺激下，刺激并没有增加自我参照语境记忆效应的幅度。这些结果表明，在编码时刺激 dmPFC 可能不会增加自我参照处理引起的记忆益处，这表明 tDCS 对记忆的影响存在边界条件。
