Neural correlates of cultural differences in moral decision making: a combined ERP and sLORETA study

Cultures affect human social behaviors including moral decision making. However, the brain mechanism underlying cross-cultural moral decision making is still unclear. In the current study, the neural correlates of cultural differences in moral decision making between Chinese and westerners were investigated by combining the event-related potential technique with standardized Low-Resolution brain Electromagnetic Tomography (sLORETA) analyses. Behavioral results showed that participants made a smaller proportion of utilitarian judgments and had longer reaction times in response to personal than impersonal dilemmas, with no obvious differences between westerners and Chinese. However, the event-related potential components were significantly different between the two cultural groups. Smaller P3 amplitudes were evoked by personal than impersonal dilemmas for westerners, while for Chinese, smaller P260 deflections were elicited by personal compared with impersonal dilemmas. The current source density analysis with sLORETA revealed significantly different brain activities for P2, P3, and P260 components elicited by personal and impersonal dilemmas. Different from the sources of P2 and P3 components, which mainly localized in cingulate gyrus and medial frontal areas, the P260 component mainly activated areas in the posterior cingulate, parahippocampal gyrus, and cuneus and precuneus cortices. These findings suggest a relatively earlier initiation of the moral decision-making process for westerners and a relatively integrated processing during the solution of moral decision making for Chinese.