Online repetitive transcranial magnetic stimulation during working memory in younger and older adults: A randomized within-subject comparison
Online repetitive transcranial magnetic stimulation during working memory in younger and older adults: A randomized within-subject comparison
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DOI：
10.1371/journal.pone.0213707
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发表时间：
2019-03-22
期刊：
影响因子：
3.7
通讯作者：
Appelbaum, L. G.
中科院分区：
文献类型：
--
作者：
Beynel, L.;Davis, S. W.;Appelbaum, L. G.
工作记忆是对存储在一个灵活的、容量有限的缓冲区中的信息进行心理操作的能力。在工作记忆中处理信息的能力对人类认知的许多方面都至关重要，但也会随着健康的衰老而下降。鉴于这种工作记忆操作能力的深远重要性，人们正在共同努力开发提高它们的方法。目前的研究测试了在线重复经颅磁刺激对健康年轻人和老年人工作记忆操纵的能力。在左背外侧前额叶皮层上施加在线高频（5Hz）重复经颅磁刺激，以验证主动重复经颅磁刺激比假刺激能显著提高记忆回忆准确性的假设，并且这些效果在年轻人和老年人认知需求最高的工作记忆操作条件下最为明显。当参与者执行延迟反应字母排序任务时，重复经颅磁刺激被应用于三个不同难度的任务。通过将电场建模与个性化功能磁共振成像激活图相结合来识别左背外侧前额叶皮层，并在实验中使用立体定向神经导航与实时机器人制导进行定位，从而在刺激期间实现最佳线圈放置。由于在年轻人和老年人之间没有发现准确性差异，两组的结果都崩溃了。随后的分析表明，与假刺激相比，主动刺激显著提高了准确性，但仅适用于最困难的条件。这些结果表明，重复经颅磁刺激对记忆增强的进一步研究将重点放在高难度条件下，因为这些条件最有可能表现出好处。
Working memory is the ability to perform mental operations on information that is stored in a flexible, limited capacity buffer. The ability to manipulate information in working memory is central to many aspects of human cognition, but also declines with healthy aging. Given the profound importance of such working memory manipulation abilities, there is a concerted effort towards developing approaches to improve them. The current study tested the capacity to enhance working memory manipulation with online repetitive transcranial magnetic stimulation in healthy young and older adults. Online high frequency (5Hz) repetitive transcranial magnetic stimulation was applied over the left dorsolateral prefrontal cortex to test the hypothesis that active repetitive transcranial magnetic stimulation would lead to significant improvements in memory recall accuracy compared to sham stimulation, and that these effects would be most pronounced in working memory manipulation conditions with the highest cognitive demand in both young and older adults. Repetitive transcranial magnetic stimulation was applied while participants were performing a delayed response alphabetization task with three individually-titrated levels of difficulty. The left dorsolateral prefrontal cortex was identified by combining electric field modeling to individualized functional magnetic resonance imaging activation maps and was targeted during the experiment using stereotactic neuronavigation with real-time robotic guidance, allowing optimal coil placement during the stimulation. As no accuracy differences were found between young and older adults, the results from both groups were collapsed. Subsequent analyses revealed that active stimulation significantly increased accuracy relative to sham stimulation, but only for the hardest condition. These results point towards further investigation of repetitive transcranial magnetic stimulation for memory enhancement focusing on high difficulty conditions as those most likely to exhibit benefits.