論文

査読有り 国際誌
2019年

Anodal Transcranial Direct Current Stimulation Induces High Gamma-Band Activity in the Left Dorsolateral Prefrontal Cortex During a Working Memory Task: A Double-Blind, Randomized, Crossover Study.

Frontiers in human neuroscience
  • Takashi Ikeda
  • ,
  • Tetsuya Takahashi
  • ,
  • Hirotoshi Hiraishi
  • ,
  • Daisuke N Saito
  • ,
  • Mitsuru Kikuchi

13
開始ページ
136
終了ページ
136
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.3389/fnhum.2019.00136

Transcranial direct current stimulation (tDCS) has been shown to have mixed effects on working memory (WM) capacity in healthy individuals. Different stimulation paradigms may account for these discrepancies, with certain features being favored. To determine the effect in the context of anodal tDCS, we investigated whether anodal tDCS induced cortical oscillatory changes during a WM task. Specifically, we tested whether anodal offline tDCS over the left prefrontal cortex (PFC) enhances WM capacity by modulating the oscillatory activity in the left dorsolateral PFC (DLPFC) using magnetoencephalography (MEG). This study employed a double-blind, randomized, crossover design, in which 24 healthy right-handed participants conducted MEG recordings during a 3-back task after administration of 2 mA tDCS or sham stimulation as a placebo. Our results showed that the effect of tDCS did not appear in the behavioral indices-WM accuracy (d') or reaction time (RT). From the results of the time-frequency analysis, significant event-related synchronization (ERS) in the high-gamma band (82-84 Hz) of the left DLPFC was found under the tDCS condition; however, ERS was not correlated with WM capacity. Furthermore, we calculated the modulation index (MI), which indicates the strength of phase-amplitude coupling (PAC). tDCS significantly decreased MI of the left DLPFC, representing the theta-gamma PAC during the n-back task using color names as verbal stimuli. Our results suggest that although tDCS increased the gamma-band oscillation indicating greater neural activity in the left DLPFC, it did not lead to an improvement of WM capacity; this may be due to the inability of gamma-band oscillation to couple with the task-induced theta wave. WM capacity might not increase unless theta-gamma PAC is not enhanced by tDCS.

リンク情報
DOI
https://doi.org/10.3389/fnhum.2019.00136
PubMed
https://www.ncbi.nlm.nih.gov/pubmed/31105540
PubMed Central
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6491895
ID情報
  • DOI : 10.3389/fnhum.2019.00136
  • PubMed ID : 31105540
  • PubMed Central 記事ID : PMC6491895

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