The effects of transcranial direct current stimulation on working memory in the elderly with normal cognitive impairments

Abstract

Objective: Reduced cognitive function is one of the problems caused by aging, which leads to reduced performance of the elderly. This is a study to evaluate the effects of transcranial Direct Current Stimulation (tDCS) on working memory in the elderly with normal cognitive impairments. Methods: In this clinical trial, 45 elderlies participating in a self-care educational course in Zahedan, Iran, in 2016, were assigned into three groups of F3, F4, and sham stimulation. From all the participants, 2-back, forward and backward digit span, and Mini Mental State Examination (MMSE) tests were taken. Results: The three groups showed no significant difference in the mean score of 2-back test at different time points.The three groups showed no significant difference in mean score of backward digit span test at different time points. The mean score of backward digit span test was significantly higher in the F3 group after the intervention. Discussion: The results of this study indicate that the score changes in the 2-back and the forward digit span tests were significant only in the F3 group. Also, the F4 group showed a significant difference at all the time points after the intervention, compared to before the intervention, but this change was less than that in the F3 group. Conclusion: This study shows that tDCS can improve working memory performance via F3method. The tDCS can cause working memory improvement and naming facilitation by stimulation.