Effects of dual-site transcranial direct current stimulation on cognitive flexibility in children with Specific...

Children with specific learning disorders (SLDs) often show impairments in cognitive flexibility, an essential component of executive functioning. This preliminary study examined the potential effects of transcranial direct current stimulation (tDCS) on cognitive flexibility in children aged 7-12 years with SLDs. In a randomized, single-blind, pretest-posttest sham-controlled design, 26 participants were allocated to either an experimental group receiving ten sessions of active brain stimulation or a sham group. Stimulation targeted the left dorsolateral prefrontal cortex (anodal) and the right ventromedial prefrontal cortex (cathodal). Cognitive flexibility was evaluated using the Wisconsin Card Sorting Test, assessing strategic thinking, rule shifting, and error patterns. Outcomes were analyzed using multivariate and univariate analyses of covariance, supplemented by change-score sensitivity analyses. Active tDCS was associated with statistically significant improvement in selected measures of cognitive flexibility compared with sham stimulation, including Total Score, Clusters, and Perseverative Errors, whereas no reliable group difference was observed for Total Time. Although these findings suggest that dual-site prefrontal tDCS may be a potentially useful approach for further investigation in children with SLDs, conclusions are limited by the small sample size, sensitivity of the multivariate findings to covariate specification, and the absence of follow-up assessments to determine whether gains persist over time.