Exploration of the Effect of Race on Cortical Current Flow Due to Transcranial Direct Current Stimulation: Comparison across Caucasian, Chinese, and Indian Standard Brains.

It is well known that genetic and environmental factors amongst others make different ethnic populations dissimilar reflected by the difference in overall skull and brain volume, shape, and size. We sought to investigate in this study the effects of race related morphological changes by comparing across standard Caucasian, Chinese and Indian templates on brain current flow due to transcranial Direct Current Stimulation. Findings indicate up to 1.4 fold variation in induced electrical field magnitude in both target and non-target regions across the electrode montage and average heads considered. The observed variation is similar to the variation observed in adults of Caucasian race indicating that variation observed due to race are not significantly more than within race variation.