Gender and parental status affect the visual cortical response to infant facial expression

This study sought to determine the influence of gender and parental status on the brain potentials elicited by viewing infant facial expressions. We used ERP recording during a judgement task of infant happy/distressed expression to investigate if viewer gender or parental status affects the visual cortical response at various stages of perceptual processing. ERPs were recorded in 38 adults (male/female, parents/non-parents) during processing of infant facial expressions that varied in valence and intensity. All infants were unfamiliar to viewers. The lateral occipital P110 response was much larger in women than in men, regardless of facial expression, thus indicating a gender difference in early visual processing. The occipitotemporal N160 response provided the first evidence of discrimination of expressions of discomfort and distress and demonstrated a significant gender difference within the parent group, thus suggesting a strong interactive influence of genetic predisposition and parental status on the responsivity of visual brain areas. The N245 component exhibited complete coding of the intensity of facial expression, including positive expressions. At this processing stage the cerebral responses of female and male non-parents were significantly smaller than those of parents and insensitive to differences in the intensity of infant suffering. Smaller P300 amplitudes were elicited in mothers versus fathers, especially with infant expressions of suffering. No major group differences were observed in cerebral responses to happy or comfortable expressions. These findings suggest that mere familiarity with infant faces does not explain group differences.