Gene by Culture Effects on Emotional Processing of Social Cues among East Asians and European Americans

Abstract

While Western cultures are more focused on individualization and self-expression, East Asian cultures promote interrelatedness. Largely unknown is how gene by culture interactions influence the degree to which individuals acquire culture, and the neurocircuitry underlying how social cues are processed. We sought to examine the interaction between DRD4 polymorphism and culture in the neural processing of social emotional cues. 19 Asian-born East Asian (AA) and 20 European American (EA) participants performed a shifted attention emotion appraisal functional magnetic resonance imaging (fMRI) task, which probes implicit emotional processing and regulation in response to social emotional cues. Half of the participants in each group were DRD4 2- or 7-repeat allele (2R/7R) carriers. AA participants showed larger left and right amygdala, and left hippocampal activation during implicit processing of fearful faces. There was a gene by culture interaction in the left insula during implicit processing of facial cues, while activation in EA DRD4 2R/7R carriers was larger than EA non-carriers and AA carriers. Our findings suggest that emotional facial cues are more salient to AA participants and elicit a larger amygdala reaction. Gene by culture interaction finding in insula suggests that DRD4 2R/7R carriers in each culture are more prone to adopting their cultural norm.

Keywords: amygdala; culture; emotion; gene; insula; social.

Figure 1

Left: whole brain activation for the Gender > FacePlace contrast. In this image, the insulas, fusiform gyri, and amygdalae are visible. Middle: graph shows betas for this contrast extracted from left amygdala. Right: graph shows betas for this contrast extracted from left insula. AA: Asian-born Asian; EA: European American. * p < 0.05 (Y axis represents beta values).

Figure 2

Left: whole brain activation for the In/Out > Gender contrast. In this image, the posterior cingulate cortex and parahippocampi are visible. Right: graph shows betas for this contrast extracted from right parahippocampus. AA: Asian-born Asian; EA: European American. Activation in EA participants is significantly larger than AA participants.