P1 Component Discloses Gender-Related Hemispheric Asymmetries during IAPS Processing

Background: Although some studies showed distinct electrophysiological correlates of emotions in men and women about 300 ms after the stimulus onset, little is known about the automatic visual phases of emotional processing. Investigating both early and late event-related potential (ERP) components (e.g., the P1, P300) could allow us to clarify the effect of gender on the temporal dynamics underlying emotional processing. Methods: Twenty men and twenty women similar in age, education and empathy traits passively viewed emotional and neutral IAPS pictures during EEG recording, providing their subjective evaluations about valence and arousal. ERP and source analyses were implemented to examine gender effects on emotional processing. Results: The P1 analysis revealed gender-related asymmetries, consisting of the greater amplitude of right vs. left parietal sites for women, and bilateral activation for men, almost for each emotional category. These findings were also supported by source analyses. Conversely, during the fear stimulus processing, women showed an involvement of the left cuneus, and men of the right homologous. No group differences appeared in the P300 component analysis. Conclusions: Our findings support the hypothesis that men and women adopt different strategies when processing visual emotional information, and suggest that gender is a crucial variable in emotional research.