Comparison of the effect of Transcranial Direct Current Stimulation (tDCS (and Transcranial Random Noise Stimulation (tRNS (combined with cognitive training on working memory performance of people with attention deficit/hyperactivity disorder

This study aimed to comparison of the effect of Transcranial Direct Current Stimulation (tDCS) and Transcranial Random Noise Stimulation (tRNS) combined with cognitive training on working memory performance of people with attention deficit/hyperactivity disorder. For this purpose, 45 children with attention deficit hyperactivity disorder in zahedan city were purposefully selected as the research sample. Subjects were divided into three groups: tDCS, tRNS and placebo group. Subjects in the experimental groups received 5 sessions of electrical stimulation (tDCS and tRNS) with an interval of 24 hours between each session; placebo group also received fake stimulation (non-effective). At the same time, all subjects also received cognitive rehabilitation of working memory. All subjects were evaluated before and after the stimulation and one week after the stimulation using the N-back task and the Wechsler Digit span test. The data were analyzed using repeated measures analysis of variance. The results showed that in the tDCS group, there was a significant difference in most working memory components from the pre-test stage to the follow-up (p<0.001). In the tRNS group, a significant difference was found in the component of direct digit span and reverse digit span in the research stages. In the comparison between the two experimental groups, the effectiveness of the tDCS group was higher than that of the tRNS group. Also, no significant difference was found in most of the components between the tRNS and placebo groups (p>0.05). Overall, the results of this study show that tDCS was more effective than tRNS in working memory and this method can be used together with other treatments to improve the working memory of children with attention deficit/hyperactivity disorder.