The benefits of simultaneous tDCS and working memory training on transfer outcomes: A systematic review and meta-analysis

Valentina Pergher; Jacky Au; Mahsa Alizadeh Shalchy; Emiliano Santarnecchi; Aaron Seitz; Susanne M. Jaeggi; Lorella Battelli

Brain Stimulation (Nov 2022)

The benefits of simultaneous tDCS and working memory training on transfer outcomes: A systematic review and meta-analysis

Valentina Pergher,
Jacky Au,
Mahsa Alizadeh Shalchy,
Emiliano Santarnecchi,
Aaron Seitz,
Susanne M. Jaeggi,
Lorella Battelli

Affiliations

Valentina Pergher: Department of Psychology, Harvard University, Cambridge, MA, USA; Laboratory of Neuro and Psychophysiology, KU Leuven University, Belgium; Corresponding author. Department of Psychology, Harvard University, Cambridge, MA, USA.
Jacky Au: School of Education, University of California, Irvine, Irvine, CA, USA
Mahsa Alizadeh Shalchy: Department of Psychology, University of California, Riverside, CA, USA
Emiliano Santarnecchi: Precision Neuroscience & Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
Aaron Seitz: Department of Psychology, University of California, Riverside, CA, USA
Susanne M. Jaeggi: School of Education, University of California, Irvine, Irvine, CA, USA; Department of Cognitive Sciences, University of California, Irvine, Irvine, CA, USA; Corresponding author. School of Education, University of California, Irvine, Irvine, CA, USA.
Lorella Battelli: Department of Psychology, Harvard University, Cambridge, MA, USA; Center for Neuroscience and Cognitive Systems@UniTn, Istituto Italiano di Tecnologia, Rovereto, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation and Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA

Journal volume & issue: Vol. 15, no. 6
pp. 1541 – 1551

Abstract

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Background: Transcranial direct current stimulation (tDCS) has shown potential as an effective aid to facilitate learning. A popular application of this technology has been in combination with working memory training (WMT) in order to enhance transfer effects to other cognitive measures after training. Objective: This meta-analytic review aims to synthesize the existing literature on tDCS-enhanced WMT to quantify the extent to which tDCS can improve performance on transfer tasks after training. Furthermore, we were interested to evaluate the moderating effects of assessment time point (immediate post-test vs. follow-up) and transfer distance, i.e., the degree of similarity between transfer and training tasks. Methods: Using robust variance estimation, we performed a systematic meta-analysis of all studies to date that compared WMT with tDCS to WMT with sham in healthy adults. All procedures conformed to PRISMA guidelines. Results: Across 265 transfer measures in 18 studies, we found a small positive net effect of tDCS on improving overall performance on transfer measures after WMT. These effects were sustained at follow-up, which ranged from 1 week to one year after training, with a median of 1 month. Additionally, although there were no significant differences as a function of transfer distance, effects were most pronounced for non-trained working memory tasks. Conclusions: This review provides evidence that tDCS can be effective in promoting learning over and above WMT alone, and can durably improve performance on trained and untrained measures for weeks to months after the initial training and stimulation period. In particular, boosting performance on dissimilar working memory tasks may present the most promising target for tDCS-augmented WMT.

Published in Brain Stimulation

ISSN: 1935-861X (Print); 1876-4754 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Neurosciences. Biological psychiatry. Neuropsychiatry
Website: https://www.journals.elsevier.com/brain-stimulation

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