Investigating the association between parity and the maternal neural response to infant cues.

Understanding the maternal neural response to infant affective cues has important implications for parent-child relationships. The current study employed event-related potentials (ERPs) to examine patterns in mothers' responses to infant affective cues, and evaluated the influence of maternal experience, defined by parity (i.e., the number of children a mother has) on ERP responses. Eighty-three mothers, three months postpartum, viewed photographs of displays of infant emotional faces (sad or happy) and listened to infant cries of different distress levels and a control tone. Maternal neural response was modulated by the emotional content of the auditory stimulus, as indexed by the N100 amplitude and latency. However, response to infant faces was not modulated by the emotional content of the stimuli as indexed by the N170. Neither N100 nor N170 were affected by parity. Maternal engagement with auditory stimuli, as indexed by the P300, was modulated by the emotional content of the cry and was affected by parity. A similar parity effect was observed for the P300 response to infant faces. Results suggest that parity may play an important role at later stages of maternal infant cue perception.