Maternal oxytocin response predicts mother-to-infant gaze

Abstract

The neuropeptide oxytocin is importantly implicated in the emergence and maintenance of maternal behavior that forms the basis of the mother-infant bond. However, no research has yet examined the specific association between maternal oxytocin and maternal gaze, a key modality through which the mother makes social contact and engages with her infant. Furthermore, prior oxytocin studies have assessed maternal engagement primarily during episodes free of infant distress, while maternal engagement during infant distress is considered to be uniquely relevant to the formation of secure mother-infant attachment. Two patterns of maternal gaze, maternal gaze toward and gaze shifts away from the infant, were micro-coded while 50 mothers interacted with their 7-month-old infants during a modified still-face procedure. Maternal oxytocin response was defined as a change from baseline in the mother's plasma oxytocin level following interaction with her infant. The mother's oxytocin response was positively associated with the duration of time her gaze was directed toward her infant, while negatively associated with the frequency with which her gaze shifted away from her infant. Importantly, mothers who showed low/average oxytocin response demonstrated a significant decrease in their infant gaze during periods of infant distress, while such change was not observed in mothers with high oxytocin response. The findings underscore the involvement of oxytocin in regulating the mother's responsive engagement with her infant, particularly in times when the infant's need for access to the mother is greatest. This article is part of a Special Issue entitled Oxytocin and Social Behav.

Keywords: Distress; Engagement; Mother-to-infant gaze; Mothering; Oxytocin.

© 2013 Published by Elsevier B.V.

Figures

Figure 1

The modified still-face procedure (MSFP): (a) diagram of the experimental setting and (b) example still frames from all three phases.

Figure 2

Duration of positive and negative affect displayed by infants across modified still-face procedure (MSFP) phases. The duration values on y-axis were adjusted for the total length of the each respective phase of the MSFP and represent mean proportion values. Positive affect dropped and negative affect increased in phase 2, while a rebound in positive affect and a carry-over of negative affect were seen in phase 3. *** p < .001

Figure 3

(a) Duration of maternal gaze toward infant and (b) frequency of maternal gaze shift away from infant as a function of maternal oxytocin response (OTResp; mean ± SD) and phase of the modified still-face procedure. The y-axes indicate log-transformed values. The statistical significance of the gaze differences between phases 1 and 3 is noted at low (i.e., −1 SD) and average (i.e., mean) levels of maternal oxytocin response. * p < .05,** p < .01

Figure 4

Mother-infant interaction procedure and oxytocin response (OTResp) calculation. Measurements of plasma oxytocin were obtained from mothers at four time points: (a) following the first period of mother-infant separation (OT1), (b) following two periods of mother-infant interaction (OT 2 and OT 3), and (c) following the final period of mother-infant separation (OT 4)