Are there sex differences in averaged evoked responses produced by coupling sound and light in children and adults?

Averaged evoked response (AER) amplitudes have been reported to be larger in women than in men. The aim of this study was to determine whether AER changes produced by coupling sound and light differed between males and females (adults and children). Given the 3:1 male-female ratio in early infantile autism, we reasoned that information about sex-related differences in normal subjects might be important in interpreting the results in autism. We observed the characteristic AER changes when coupling sound and light: increased response amplitude over the occiput for both adults and children, decreased response amplitude over the vertex for adults and N1 decreased and P2 increased response amplitude over the vertex for children. Differences appeared as a function of sex in adults: the number and the amplitudes of AERs recorded in women were greater than in men with the exception of the P2 peak recorded over the occiput which was similar for males and females. The sex-related differences observed in the number and amplitudes of AERs are reduced when coupling sound and light.