Association between categorization of emotionally-charged and neutral visual scenes and parameters of event-related potentials in carriers of COMT, HTR2A, BDNF gene polymorphisms

Abstract

<ns4:p><ns4:bold>Background: </ns4:bold>This study aimed to discover the association between parameters of event-related potentials (ERPs) and categorization of images of visual scenes, both emotionally-charged and neutral, in carriers of polymorphisms of the COMT, HTR2A, BDNF genes.</ns4:p><ns4:p> <ns4:bold>Methods: </ns4:bold>Electroencephalogram (EEG) and ERPs were recorded at 128 leads, with two ear referents. Images of different visual scenes were presented to the study participants sequentially on a monitor screen. The participants’ task was to examine these images and indicate what emotions (negative, neutral or positive) they elicit. Comparison of event-related potentials was carried out using unpaired Student t-test in EEGLAB toolbox.</ns4:p><ns4:p> <ns4:bold>Results: </ns4:bold><ns4:italic><ns4:underline>COMT.</ns4:underline></ns4:italic> A stronger reaction, as reflected in the amplitude of the ERPs, in participants with the recessive homozygous Met/Met genotype was observed on latency around 200 ms to the stimuli, assessed as positive. Carriers of dominant homozygous Val/Val genotype had higher amplitude of 200 ms peak when assessed scene images as either neutral or negative in comparison to other genotypes. Participant with the Val/Met heterozygous genotype had higher amplitude of ERP that Met/Met group on same latency when assessed stimuli as negative.</ns4:p><ns4:p> <ns4:italic><ns4:underline>HTR2A</ns4:underline></ns4:italic><ns4:underline>.</ns4:underline> Significant increase in negativity in the parietal-occipital regions revealed in the range of 350-420 ms in participants with the recessive homozygous A/A genotype when choosing any type of assessment, compared to carriers of the heterozygous genotype A/G and the dominant homozygous G/G genotype.</ns4:p><ns4:p> <ns4:italic><ns4:underline>BDNF.</ns4:underline></ns4:italic> Participants with Val/Val genotype categorized the visual images more thoroughly, as reflected in greater activation of the parietal-occipital zones and higher amplitude on ERP peak on 190 ms (negative assessment) and 160 ms (neutral assessment) then Val/Met carriers.</ns4:p><ns4:p> <ns4:bold>Conclusions: </ns4:bold>The COMT, HTR2A, BDNF gene polymorphisms are associated with the process of categorizing emotionally charged and neutral visual scenes, and this relationship is reflected in the ERP parameters.</ns4:p>