Department of Psychology, University of North Texas, Denton, Texas.
Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois.
Brain Behav. 2019 Apr;9(4):e01228. doi: 10.1002/brb3.1228. Epub 2019 Mar 14.
The prefrontal cortex has been implicated in episodic memory and the awareness of memory. Few studies have probed the nature and necessity of its role via brain stimulation. There are uncertainties regarding whether the hemisphere of stimulation predicts effects on memory and whether effects of stimulation are format-specific, with most previous studies utilizing verbal/semantic stimuli.
Our primary objective was to determine if theta-burst transcranial magnetic stimulation (TBS) to prefrontal cortex modulates visual memory accuracy, visual memory awareness, or both, and whether these effects depend on brain hemisphere.
We administered TBS to 12 individuals in either left prefrontal, right prefrontal, or a sham location on three separate days. We then administered a visual associative-memory task incorporating global-level awareness judgments and feeling-of-knowing (FOK) judgments on test trials for which retrieval failed.
Overall memory accuracy significantly improved after right hemisphere TBS compared to sham. Simultaneously, subjects were relatively underconfident after right TBS, suggesting minimal awareness of memory accuracy improvements. The correspondence between FOKs and later recognition accuracy suggested a pattern of disruption in prospective memory monitoring accuracy after left TBS.
Our findings provide unique evidence for improved visual memory accuracy after right prefrontal TBS. These results also suggest right prefrontal lateralization for visual memory and left-hemisphere specialization for item-level prospective memory awareness judgments. Taken together, these results provided continued support for noninvasive stimulation to prefrontal cortex as a means of potentially improving memory and causally influencing prospective memory awareness.
前额叶皮层与情景记忆和记忆意识有关。很少有研究通过大脑刺激来探究其作用的性质和必要性。对于刺激的半球是否能预测对记忆的影响，以及刺激的效果是否具有格式特异性（大多数先前的研究都使用言语/语义刺激），存在不确定性。
我们的主要目的是确定经颅磁刺激（TBS）是否会调节前额叶皮质的视觉记忆准确性、视觉记忆意识，或者两者兼而有之，以及这些影响是否取决于大脑半球。
我们在三天内分别对 12 名个体的左前额叶、右前额叶或假刺激位置进行 TBS 治疗。然后，我们在测试中加入了视觉联想记忆任务，包括全局水平的意识判断和失败提取的感觉判断。
与假刺激相比，右半球 TBS 后整体记忆准确性显著提高。同时，右 TBS 后受试者的相对自信度较低，表明对记忆准确性提高的意识较低。FOK 与后期识别准确性之间的一致性表明，左 TBS 后前瞻性记忆监测准确性受到干扰。
我们的发现为右前额叶 TBS 后视觉记忆准确性的提高提供了独特的证据。这些结果还表明，视觉记忆存在右前额叶偏侧化，而项目水平的前瞻性记忆意识判断则存在左侧化。总的来说，这些结果为使用前额叶皮层非侵入性刺激来提高记忆和因果性地影响前瞻性记忆意识提供了持续支持。
