Severity of depressive symptoms and oscillatory responses to emotional facial expressions

Differences in oscillatory responses to emotional facial expressions were studied in 40 subjects (19 men and 21 women aged from 18 to 30 years) varying in severity of depressive symptoms. Compared with perception of angry and neutral faces, perception of happy faces was accompanied by lower Δ synchronization in subjects with a low severity of depressive symptoms (Group 2) and higher Δ synchronization in subjects with a high severity of depressive symptoms (Group 1). Because synchronization of Δ oscillations is usually observed in aversive states, it was assumed that happy faces were perceived as negative stimuli by the Group 1 subjects. Perception of angry faces was accompanied by α desynchronization in Group 2 and α synchronization in Group 1. Based on Klimesch’s theory, the effect was assumed to indicate that the Group 1 subjects were initially set up for perception of negative emotional information. The effect of the emotional stimulus category was significant in Group 2 and nonsignificant in Group 1, testifying that the recognition of emotional information is hindered in depression-prone individuals.