ABSTRACT
Cultural background influences social cognition, however no study has examined brain stimulation differences attributable to cultural background. 104 young adults [52 South-East Asian Singaporeans (SEA); 52 Caucasian Australians (CA)] received anodal high-definition transcranial direct current stimulation (HD-tDCS) to the dorsomedial prefrontal cortex (dmPFC) or the right temporoparietal junction (rTPJ). Participants completed tasks with varying demands on self-other processing. At baseline, SEA showed greater self-other integration than CA. Anodal HD-tDCS to the dmPFC resulted in the CA performing closer to the SEA. Baseline performance on a mental rotation task and the self-reference effect in memory (SRE) was comparable between groups. In the combined sample, rTPJ HD-tDCS decreased interference from the egocentric perspective during mental rotation and dmPFC HD-tDCS removed the SRE. Stimulation effects were comparable when baseline performance was comparable. When baseline performance differed, stimulation differences were identified. Therefore, cultural background is an important consideration in social brain stimulation studies.