Parenting Stress Undermines Mother-Child Brain-to-Brain Synchrony: A Hyperscanning Study

Abstract

Synchrony refers to the coordinated interplay of behavioural and physiological signals that reflect the bi-directional attunement of one partner to the other's psychophysiological, cognitive, emotional, and behavioral state. In mother-child relationships, a synchronous pattern of interaction indicates parental sensitivity. Parenting stress has been shown to undermine mother-child behavioural synchrony. However, it has yet to be discerned whether parenting stress affects brain-to-brain synchrony during everyday joint activities. Here, we show that greater parenting stress is associated with less brain-to-brain synchrony in the medial left cluster of the prefrontal cortex when mother and child engage in a typical dyadic task of watching animation videos together. This brain region overlaps with the inferior frontal gyrus, the frontal eye field, and the dorsolateral prefrontal cortex, which are implicated in inference of mental states and social cognition. Our result demonstrates the adverse effect of parenting stress on mother-child attunement that is evident at a brain-to-brain level. Mother-child brain-to-brain asynchrony may underlie the robust association between parenting stress and poor dyadic co-regulation. We anticipate our study to form the foundation for future investigations into mechanisms by which parenting stress impairs the mother-child relationship.

Figure 1

Illustration depicting the set-up of devices and sitting arrangement of mother-child dyads during the experimental sessions. Figure illustrated by Nur Hasyimah Bte Johari.

Figure 2

Schematic diagram representing the video stimuli screened to participants. A 5-sec fixation point “+” was presented before the onset of the first video clip. Three 1-min video clips were screened in total, with an inter-stimulus interval of 10 sec between each clip. The order of presentation of the three video clips was randomised such that six video sequences were generated. Mother-child dyads were randomly assigned to one of six video sequences.

Figure 3

Schematic diagram depicting locations of the 20 optode channels and their corresponding positions with respect to the superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), and anterior prefrontal cortex (aPFC). Channels were grouped into the following clusters: frontal left, frontal right, medial left, and medial right.

Figure 4

Scatterplot depicting the positive linear relation between reported parenting stress by mothers and normalised distance index in the medial left cluster (r = 0.56, p = 0.0032; FDR corrected).