Recognition of Emotional and Neutral Visual Scenes in Carriers of the MAOA, COMT, DRD4, and 5HT2A Gene Polymorphisms

Abstract

It is known that some genes regulate neurochemical metabolism, and their polymorphisms affect cognitive performance, including the ability to categorize emotionally significant information. The aim of our study was to analyze the recognition of emotional and neutral visual scenes in carriers of different polymorphic variants of the MAOA, COMT, DRD4, and 5HT2A genes. The study sample consisted of 87 university students (Caucasians, women 63%, average age 20.4±2.6 years). The genotypes of the COMT, 5HT2A, and DRD4 genes were determined by polymerase chain reaction. Agarose gel electrophoresis was used to determine the number of tandem repeats of the MAOA gene. Three hundred sixty (360) photographic images of scenes of different emotional valence (positive, negative, and neutral - 120 images for each category) were used as stimuli. These images were classified by expert assessments. The images were presented in a random sequence. The exposure time was 700 ms. The research participants were asked to determine the emotional valence of each scene. We found that only the COMT gene genotype affected the recognition of emotional and neutral visual scenes. Carriers of the COMT Val/Val genotype, which causes dopamine to stay in the synaptic space for a shorter time, are better in recognizing and demonstrate higher sensitivity to the emotional content of scenes. Carriers of the Val/Met genotype demonstrated the worst ability to differentiate the emotional valence of visual scenes. This study has shown that the length of stay of monoamines in the synaptic space regulated by the COMT gene affects the recognition of emotional visual information.