The neural mechanism underlying the female advantage in identifying negative emotions: an event-related potential study.

Previous studies have extensively reported an advantage of females in identifying negative facial emotions as compared with males. Nevertheless, why females are better in performance relative to males during emotion recognition tasks is still unknown, and the neural mechanism(s) underlying this phenomenon has yet to be directly investigated. As facial affects convey emotional information which is adaptively important and the recognition of a given facial affect generally evokes individuals' emotion of the same type [Dimberg, U., 1997. Facial reactions: rapidly evoked emotional responses. J. Psychophysiol. 11, 115-123], the present study assumes that the female advantage in emotion recognition may result from the attenuated sensitivity of males to emotionally negative stimuli of lesser valence intensity compared to that of females. In contrast, each gender may be comparably sensitive to emotionally negative stimuli of enhanced salience as suggested by the emotional negativity bias. To test this hypothesis, event-related potentials were recorded for highly negative (HN), moderately negative (MN), and Neutral deviant images while subjects (15 males, 15 females) perform a standard/deviant categorization task, irrespective of the emotional valence of deviants. The results demonstrated more negative ERP deflections during HN condition than during MN and Neutral conditions at early N2 and later P3 components, irrespective of gender. Moreover, MN condition elicited significantly more negative deflections than the Neutral condition across N2 and P3 components only in females, and the MN-Neutral difference waveform in females during 250-450 ms interval was localized to the right prefrontal cortex. Thus, apart from the increased sensitivity of both genders to the highly negative stimuli, the present study demonstrated that women, instead of men, are sensitive to emotionally negative stimuli of lesser saliency, which may be an important mechanism underlying the female advantage in identifying negative emotions, and the right prefrontal cortex may be the neural basis underlying the female-specific sensitivity to emotionally negative stimuli of lesser salience.