Auditory Evoked Potentials and Hand Preference in 6-Month-Old Infants: Possible Gender-Related Differences in Cerebral Organization

Normal 6-month-old infants (10 male and 10 female) were studied to determine if cortical auditory evoked potentials recorded to probe stimuli during verbal and musical stimulus presentation provided an index of cerebral functional organization. Furthermore, evoked potential left-right amplitude asymmetries were examined in relation to gender differences and hand-reaching preference in these infants. Six-month-old girls exhibited evoked potential amplitude asymmetries associated with the stimulus conditions, whereas boys did not. In addition, both boys and girls showed associations between their patterns of evoked potential asymmetry and their hand-reaching preference. The patterns of electrophysiological responses observed and their relation to hand preference suggest that the rate of maturation of the left and right hemispheres differs and is dependent on the gender of the infant.