An Event-related Potential Study Of Different Levels Of Neuroticism Influence On Individual Responses To Emotional Stimuli

One of basic personality traits, neuroticism is strongly associated with emotion and may thus moderate individual responses to emotional stimuli. The present study used event-related potential (ERP) to test whether individual differences in brain cortical reactivity to emotional stimuli are correlated with neuroticism in healthy adults. ERPs were recorded from 15 high neurotic and 15 low neurotic participants, who were selected from 292 college students according to the scores in neuroticism and extraversion of Eysenck Personality Questionnaire-Revised, Short Scale for Chinese (EPQ-RSC). 30 participants were presented slides of International Affective Picture System (IAPS) posing 50 positive, 50 negative and 50 neutral pictures, which were presented with brief exposure and distinct sequences of six pictures. To concentrate their attention, the subjects were instructed to realize a valence categorization task.In all subjects, the positive, negative and neutral pictures elicited obvious late positive potentials in the picture perception paradigm, which can begin at about 300ms after onset and may be sustained to 750ms. From 300ms to 500ms, positive, neutral pictures elicited larger amplitudes as compared to negative pictures in all subjects at Fz, Cz sites, while it is different at Oz, T5, T6 sites that positive, negative pictures elicited larger amplitudes as compared to neutral pictures. From 600ms to 740ms, a significant main effect in personality was found between high neurotic and low neurotic subjects when watching positive and negative pictures at F3, Fz sites: high neurotic subjects watching emotional pictures produced smaller amplitudes as compared to low neurotic subjects. Furthermore, a significant interaction of neuroticism and emotion was found at T5 site: high neurotic subjects watching positive pictures produced smaller amplitudes.In summary, brain cortical responses to different valence of emotional pictures is different, and individual with different levels of neuroticism has different brain cortical responses to emotional pictures. In the ERP study of emotion, the sustained positivity may reflect motivational engagement and a commitment of attentional resources to the picture viewing task. It supports the view that there are probably association between neuroticism and emotional responses. Furthermore, the difference of the responses to emotional pictures between high neurotic and low neurotic individuals can be reflected by event-related potentials. The results also approved that the frontal lobe and the temporal lobe are closely correlated with emotional processing of neurotic individuals which may be left-hemisphere lateral.