Motherhood and oxytocin receptor genetic variation are associated with selective changes in electrocortical responses to infant facial expressions.

Abstract

Recent studies suggest that parental caregiving is associated with adaptive changes in neurocognitive responses to emotional cues and oxytocin function, possibly reflecting the increased need of parents to monitor infants’ emotional states. In the current study, we investigated whether the changes associated with motherhood and oxytocin receptor genetic variation rs53576 are specific to the processing of infant cues as opposed to a more general increase in responsiveness to emotional cues. We measured event-related brain potentials (ERPs) and behavioral recognition responses from mothers of young infants (n = 48) and nulliparous females (n = 46) to infant and adult faces displaying strong and mild intensity emotional expressions. Mothers and GG allele carriers of the OXTR gene showed an early latency (∼100 ms) differential frontal ERP response to strong intensity facial expressions, and mothers also showed modulation of the posterior EPN waveform by negative valence. The early frontal ERP modulation was associated with faster emotion recognition performance across participants. Most importantly, these effects were highly specific to infant facial expressions. The results point to a dissociable neurocognitive system that is involved in monitoring infants’ emotional cues and may be important in supporting parental caregiving in humans.

The neural basis of responsive caregiving behaviour: Investigating temporal dynamics within the parental brain

“…Some studies reported no effect of valence on N170 responses [80,81]. However, another study demonstrated larger N170 amplitudes to negative compared to positive infant facial expressions during focused attention in both mothers and non-mothers, as well as a main effect of valence on latency of N170 responses [78]. For later EEG components, findings show greater concordance.…”

“…One study has demonstrated a main effect of valence of infant facial expressions (happy, neutral, distressed) on the amplitude of N100 responses in both mothers and nulliparous women [78]. Other studies have reported no significant effect of valence on such early responses [79,80].…”

“…Two studies demonstrated effects of valence on responses between 200 and 300 ms (early posterior negativity at 240-300 ms, [78]; N245 at 210-280 ms, [79]). Both intensity and valence of emotional expression were shown to affect the amplitude of P300 responses in one study (375-600 ms, [79]), although another study found no such difference in a comparable time window (300-450 ms, [78]). Two studies have demonstrated modulation of the late positive potential (LPP; 500-800 ms) by valence in infant cues [81,97].…”

“…For example, mothers were found to demonstrate shorter N1 latencies in response to infant facial expressions [78] and greater amplitude of N1 peaks in response to cry vocalisations [112] and facial expressions [79] compared to non-mothers. However, other studies have demonstrated no effect of parental status on P1 responses [80].…”

The Application of Electroencephalography to Investigate the Neural Bases of Parenting: A Review

“…Consistent with ERP findings, RTs were significantly faster to evaluate negative emotional states compared to positive ones, with the fastest times in response to distress expressions. More recently, Peltola and colleagues (2014) replicated this ERP finding in a sample of women: the N170 amplitude in response to infant faces was larger to negative affective infant faces compared to positive affect across a sample of mothers and non-mothers.…”