Sex-related ERP differences in deviance detection

The effect of sex on neural mechanisms of auditory mismatch detection was examined using dense sensor array (128 channel) event-related potential recordings (ERPs). ERPs of 32 right-handed subjects (16 males) were recorded to frequent (85%, 880 Hz) and infrequent (15%, 1480 Hz) tones. There were no sex differences in mismatch negativity (80–180 ms), however, the fronto-central P2 (180–260 ms) was less positive in males (F=12.56, P<0.005) and the N2 (260–340 ms) was more negative in males (F=6.28, P<0.05). The increased negativity in males spanning the P2 and N2 may index a top–down process of attention bias towards novelty. This result supports the hypothesis of an adaptive, sexually dimorphic processing of novel events in humans.