Child maltreatment severity and sleep variability predict mother–infant RSA coregulation

Regulatory processes underlie mother-infant interactions and may be disrupted in adverse caregiving environments. Child maltreatment and sleep variability may reflect high-risk caregiving, but it is unknown whether they confer vulnerability for poorer mother–infant parasympathetic coordination. The aim of this study was to examine mother–infant coregulation of respiratory sinus arrhythmia (RSA) in relation to child maltreatment severity and night-to-night sleep variability in 47 low-income mother–infant dyads. Maternal and infant sleep was assessed with actigraphy and daily diaries for 7 nights followed by a mother–infant still-face procedure during which RSA was measured. Higher maltreatment severity was associated with weakened concordance in RSA coregulation related to the coupling of higher mother RSA with lower infant RSA, suggesting greater infant distress and lower maternal support. In addition, higher infant sleep variability was associated with infants’ lower mean RSA and concordance in lagged RSA coregulation such that lower maternal RSA predicted lower infant RSA across the still-face procedure, suggesting interrelated distress. The findings indicate that adverse caregiving environments differentially impact regulatory patterns in mother–infant dyads, which may inform modifiable health-risk behaviors as targets for future intervention.

Familiar songs reduce infant distress

Parents commonly vocalize to infants to mitigate their distress, especially when holding them is not possible. Here we examined the relative efficacy of parents’ speech and singing (familiar and unfamiliar songs) in alleviating the distress of 8- and 10-month-old infants (n = 68 per age group). Parent–infant dyads participated in 3 trials of the Still Face procedure, featuring a 2-min Play Phase, a Still Face phase (parents immobile and unresponsive for 1 min or until infants became visibly distressed), and a 2-min Reunion Phase in which caregivers attempted to reverse infant distress by (a) singing a highly familiar song, (b) singing an unfamiliar song, or (c) expressive talking (order counterbalanced across dyads). In the Reunion Phase, talking led to increased negative affect in both age groups, in contrast to singing familiar or unfamiliar songs, which increased infant attention to parent and decreased negative affect. The favorable consequences were greatest for familiar songs, which also generated increased smiling. Skin conductance recorded from a subset of infants (n = 36 younger, 41 older infants) revealed that arousal levels were highest for the talking reunion, lowest for unfamiliar songs, and intermediate for familiar songs. The arousal effects, considered in conjunction with the behavioral effects, confirm that songs are more effective than speech at mitigating infant distress. We suggest, moreover, that familiar songs generate higher infant arousal than unfamiliar songs because they evoke excitement, reflected in modestly elevated arousal as well as pleasure, in contrast to more subdued responses to unfamiliar songs.

Frontal electroencephalogram (EEG) asymmetry reactivity: Exploring changes from baseline to still face procedure response

Electroencephalogram (EEG) asymmetry has been widely studied across the lifespan, with multiple studies conducted in infancy. However, few have investigated frontal EEG asymmetry in the context of emotional-eliciting tasks, controlling for baseline to focus on an experimental episode response. The present study was designed to address this gap in research, predicting frontal EEG asymmetry response in the context of the Still Face procedure (SFP), examining mother–infant interaction quality and infant temperament attributes as potential contributors. Moderation by infant temperament was also considered. Results indicated that intensity and tone of parent–child interactions as well as Surgency/Positive Affectivity (and component scales of Approach and Activity Level) predicted frontal EEG asymmetry during SFP, controlling for baseline. Importantly, moderation was noted for Surgency/Positive Affectivity and its Approach component, reflected in significant interaction terms and follow-up simple slope tests. That is, the effect of intensity in mother–infant interactions was qualified by child overall surgency, and approach more specifically – infants demonstrating higher levels of Surgency/Positive Affectivity and Approach in particular were protected from the right frontal EEG response to SFP noted in the context of intense concurrent exchanges with mothers.