Demeter Elise, Mirdamadi Jasmine L, Meehan Sean K, Taylor Stephan F
Center for Cognitive Neuroscience, Duke University, Durham, USA.
School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.
Cogn Affect Behav Neurosci. 2016 Aug;16(4):724-35. doi: 10.3758/s13415-016-0426-3.
Deep semantic encoding of verbal stimuli can aid in later successful retrieval of those stimuli from long-term episodic memory. Evidence from numerous neuropsychological and neuroimaging experiments demonstrate regions in left prefrontal cortex, including left dorsolateral prefrontal cortex (DLPFC), are important for processes related to encoding. Here, we investigated the relationship between left DLPFC activity during encoding and successful subsequent memory with transcranial magnetic stimulation (TMS). In a pair of experiments using a 2-session within-subjects design, we stimulated either left DLPFC or a control region (Vertex) with a single 2-s train of short theta burst stimulation (sTBS) during a semantic encoding task and then gave participants a recognition memory test. We found that subsequent memory was enhanced on the day left DLPFC was stimulated, relative to the day Vertex was stimulated, and that DLPFC stimulation also increased participants' confidence in their decisions during the recognition task. We also explored the time course of how long the effects of sTBS persisted. Our data suggest 2 s of sTBS to left DLPFC is capable of enhancing subsequent memory for items encoded up to 15 s following stimulation. Collectively, these data demonstrate sTBS is capable of enhancing long-term memory and provide evidence that TBS protocols are a potentially powerful tool for modulating cognitive function.
言语刺激的深度语义编码有助于日后从长期情景记忆中成功检索出这些刺激。众多神经心理学和神经影像学实验的证据表明，左前额叶皮层的区域，包括左背外侧前额叶皮层（DLPFC），对与编码相关的过程很重要。在此，我们使用经颅磁刺激（TMS）研究了编码过程中左DLPFC活动与随后成功记忆之间的关系。在一对采用两阶段被试内设计的实验中，我们在语义编码任务期间用单次2秒的短θ爆发刺激（sTBS）对左DLPFC或一个对照区域（头顶）进行刺激，然后让参与者进行识别记忆测试。我们发现，与刺激头顶的那天相比，刺激左DLPFC的那天随后的记忆得到了增强，并且DLPFC刺激还增加了参与者在识别任务中对自己决策的信心。我们还探究了sTBS效应持续的时间进程。我们的数据表明，对左DLPFC进行2秒的sTBS能够增强对刺激后长达15秒内编码项目的后续记忆。总体而言，这些数据表明sTBS能够增强长期记忆，并提供证据表明TBS方案是调节认知功能的一种潜在有力工具。
