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ORIGINAL RESEARCH article

Front. Psychiatry
Sec. Neurostimulation
Volume 15 - 2024 | doi: 10.3389/fpsyt.2024.1493675
This article is part of the Research Topic Underlying Neural Mechanisms of Non-invasion Brain Stimulation in the Treatment of Psychiatric Disorders: Evidence from Neuroimaging Studies Volume II View all 3 articles

Theta transcranial alternating current stimulation over the prefrontal cortex enhances theta power and working memory performance

Provisionally accepted
Ranjan Debnath Ranjan Debnath 1*Osama Elyamany Osama Elyamany 1Jona Ruben Iffland Jona Ruben Iffland 1Jonas Rauh Jonas Rauh 2Michael Siebert Michael Siebert 1Elisa Andraes Elisa Andraes 1Gregor Leicht Gregor Leicht 2Christoph Mulert Christoph Mulert 1
  • 1 University of Giessen, Giessen, Germany
  • 2 University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany

The final, formatted version of the article will be published soon.

    Introduction: Transcranial alternating current stimulation (tACS) is a promising tool for modulating brain oscillations. This study investigated whether 5 Hz tACS could modulate neural oscillations in the prefrontal cortex and how this modulation impacts performance in working memory (WM) tasks. Method: In two sessions, 28 healthy participants received 5 Hz tACS or sham stimulation over the left dorsolateral prefrontal cortex (DLPFC) while performing tasks with high and low WM loads. Resting-state EEG was recorded before and after stimulations for 5 minutes. EEG power was measured at electrodes surrounding the stimulation site. Results: The results showed that tACS significantly improved reaction time (RT) compared to sham stimulation. This effect was task-specific as tACS improved RT only in high WM load trials, with no impact on low load trials. Moreover, tACS significantly increased EEG power at 5 Hz and in the theta band compared to pre-stimulation levels. Discussion: These findings demonstrate that tACS applied over left DLPFC modulates post-stimulation brain oscillations at the stimulation sites – known as tACS after-effects. Furthermore, the results suggest that 5 Hz tACS enhances response speed by elevating task-related activity in the prefrontal cortex to an optimal level for task performance. Conclusion: In summary, the findings highlight the potential of tACS as a technique for modulating specific brain oscillations, with implications for research and therapeutic interventions.

    Keywords: tACS (transcranial alternating current stimulation), EEG, working memory, theta power., DLPFC

    Received: 09 Sep 2024; Accepted: 11 Dec 2024.

    Copyright: © 2024 Debnath, Elyamany, Iffland, Rauh, Siebert, Andraes, Leicht and Mulert. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Ranjan Debnath, University of Giessen, Giessen, Germany

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.