Evidence for sex differences in the loudness dependence of the auditory evoked potential in humans.

Objective The loudness dependence of the auditory evoked potential (LDAEP) has been suggested as a marker of the serotonin system, although studies directly examining the relationship between acute changes in serotonin and the LDAEP have been inconsistent. Given the reported sex dichotomy in serotonin neurotransmission, this study examined if there are sex differences in the LDAEP. Methods Data from 65 healthy participants from four independent studies were pooled, and their N1/P2 slopes were quantified. Results Mean N1/P2 slopes for female participants were higher than those for male participants (p < 0.0001). Conclusion These findings suggest that the LDAEP is modulated by sex potentially because of differences in serotonergic neurotransmission, and these differences may account for some of the inconsistent findings linking serotonin function and LDAEP. Copyright (C) 2011 John Wiley & Sons, Ltd.