Fundamental biases in affective information processing are modulated by individual differences in the emotional response to environmental stimuli that may be partly based on the individual's genetic make-up. To extend prior dot probe studies on attention genetics, we used a visual-search paradigm (VSP) with pictures of angry and happy faces of both sexes as targets, neutral faces as distractors, and a varying set size. Participants were selected a priori depending on their 5-HTTLPR (s/s, s/l, l/l; on a constant rs25531 A-allele background) and COMTval158met (val/val, valmet, met/met) genotypes and were matched for sex and age. We demonstrate a bias towards angry male faces (as opposed to happy male faces) irrespective of 5-HTTLPR genotype in the first experimental block that was maintained during the second experimental block only in carriers of the s-allele, which implies differential habituation processes. While a bias towards angry male faces was observed irrespective of COMTval158met genotype, only individuals with the val/val genotype exhibited a bias towards a happy female face (as opposed to an angry female face). In sum, our results both replicate and extend prior findings in the field of attention genetics and add important pieces of information to the research on attentional biases in emotion processing.
