The polarity-dependent effects of the bilateral brain stimulation on working memory.

Content Provider	Europe PMC
Author	Keshvari, Fatemeh Pouretemad, Hamid-Reza Ekhtiari, Hamed
Copyright Year	2013
Abstract	IntroductionWorking memory plays a critical role in cognitive processes which are central to our daily life. Neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (DLFPC). This study was aimed to assess whether bilateral modulation of the DLPFC using a noninvasive brain stimulation, namely transcranial direct current stimulation (tDCS), modifies the working memory function in healthy adults.MethodsIn a randomized sham-controlled cross-over study, 60 subjects (30 Males) received sham and active tDCS in two subgroups (anode left/cathode right and anode right/cathode left) of the DLPFC. Subjects were presented working memory n-back task while the reaction time and accuracy were recorded.ResultsA repeated measures, mixed design ANOVA indicated a significant difference between the type of stimulation (sham vs. active) in anodal stimulation of the left DLPFC with cathodal stimulation of the right DLPFC [F(1,55)= 5.29, P=0.019], but not the inverse polarity worsened accuracy in the 2-back working memory task. There were also no statistically significant changes in speed of working memory [F(1,55)= 0.458,P=0.502] related to type or order of stimulation.DiscussionThe results would imply to a polarity dependence of bilateral tDCS of working memory. Left anodal/ right cathodal stimulation of DLPFC could impair working memory, while the reverser stimulation had no effect. Meaning that bilateral stimulation of DLFC would not be a useful procedure to improve working memory. Further studies are required to understand subtle effects of different tDCS stimulation/inhibition electrode positioning on the working memory.
Related Links	https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC4202567&blobtype=pdf
ISSN	2008126X
Journal	Basic and Clinical Neuroscience [Basic Clin Neurosci]
Volume Number	4
PubMed Central reference number	PMC4202567
Issue Number	3
PubMed reference number	25337351
e-ISSN	22287442
Language	English
Publisher	Iranian Neuroscience Society
Publisher Date	2013-01-01
Access Restriction	Open
Rights License	This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License which allows users to read, copy, distribute and make derivative works for non-commercial purposes from the material, as long as the author of the original work is cited properly. Copyright © 2013 Iranian Neuroscience Society
Subject Keyword	Dorsolateral Prefrontal Cortex Transcranial Direct Current Stimulation Working Memory
Content Type	Text
Resource Type	Article
Subject	Neurology (clinical) Cellular and Molecular Neuroscience