Improving Cross-cultural "Mindreading" with Electrical Brain Stimulation

A cross-cultural disadvantage exists when inferring the mental state of others, which may be detrimentalfor individuals acting in an increasingly globalized world. The dorsomedial prefrontal cortex (dmPFC) is a keyhub of the social brain involved in ToM. We explored whether facilitation of dmPFC function by focal highdefinitiontDCS can improve cross-cultural mind-reading. 52 (26 F/M) Singaporeans performed the Caucasian versionof the Reading the Mind in the Eyes Test (RMET) and received HD-tDCS to either the dmPFC or a control site(right temporoparietal junction, rTPJ) in sham-controlled, double-blinded, crossover studies. Contact with Caucasianswas determined for the Singaporean cohort as a potential mediator of RMET performance and HDtDCSresponse. 52 Caucasians completed the RMET during sham-tDCS and served as a comparison group. Across-cultural disadvantage on the RMET was confirmed in the Singaporean cohort and this disadvantage wasmore pronounced in those participants who had less contact with Caucasians. Importantly, HD-tDCS to thedmPFC improved RMET performance in those with less contact. No effect was identified for rTPJ HD-tDCS orfor the age/sex control task demonstrating task and site specificity of the stimulation effects. Electrical stimulationof the dmPFC selectively improves the rate of cross-cultural ToM inference from facial cues, effectivelyremoving cross-cultural disadvantage that was found in individuals with lower cross-cultural exposure.