Concurrent and lagged physiological synchrony during mother–child interaction and their relationship to positive affect in 8- to 10-year-old children

Mother–child interaction has been characterized by a fine-tuning of behavior and physiological activity. Yet, little is known about the dynamics of mother–child physiological synchrony during early school age and their associations to positive affect. To investigate these processes, 42 mother–child dyads, with children aged 8 to 10 years, played an interactive game while their interbeat intervals (IBI) and respiratory sinus arrhythmia (RSA) were measured simultaneously. IBI/RSA synchrony was calculated using cross-correlations of the IBI/RSA second-by-second time series for lags − 3 to + 3 seconds. Mother’s and child’s individual and shared positive affect were microcoded. During the interactive tasks, IBI and RSA synchrony significantly increased compared to control conditions. RSA and affect synchrony were significantly stronger for negative compared to positive lags indicating a stronger child leads/mother follows covariation. Further, dyad’s IBI and RSA synchrony were significantly associated to mother’s and child’s individual positive affect. Our data suggest that in low-risk community samples, mothers may respond to their children’s positive affect by matching their own affect and physiology. Investigating these temporally precise, concurrent and lagged synchrony processes may open up new avenues for understanding the ways in which parent–child interactions contribute to child developmental outcomes.


Fig. S2 :
Fig. S2: Left: Illustration of experimental design.After watching a relaxing video for 5 minutes (Rest), the first joint labyrinth game (La1) is played followed by a short break, a second game block of the joint labyrinth game (La2) and finally a single labyrinth game (Single).Right: Picture of the game material.

Table S2a .
Results of a paired sample t-test comparing the number of times the ball fell into the hole (failure) for the joint labyrinth game.

Table S2b .
Results of a Wilcoxon signed rank test comparing the number of successful rounds (Success) for the joint labyrinth game.

Table S3a .
Results of paired sample t-tests comparing synchrony of actual and shuffled pairs for the first (La1) and second (La2) joint labyrinth game.
Note. adj = FDR adjusted p-values.Lags are measured in seconds.La1 = first joint labyrinth game, La2 = second joint labyrinth game.

Table S3b .
Results of paired sample t-tests comparing synchrony of actual and shuffled pairs for the single labyrinth game (Single) and Rest.

Table S4 .
Main effects of task in linear mixed models predicting IBI / RSA synchrony.
Note. adj = FDR adjusted p-values.Lags are measured in seconds.

Table S5a .
Post hoc analyses comparing synchrony in the first joint labyrinth game (La1) to synchrony in the single labyrinth game (Single).

Table S5c .
Post hoc analyses comparing synchrony in the second joint labyrinth game (La2) to synchrony in the single labyrinth game (Single).

Table S5d .
Post hoc analyses comparing synchrony in the second joint labyrinth game (La2) to synchrony during Rest.

Table S5e .
Post hoc analyses comparing synchrony in the first joint labyrinth game (La1) to synchrony in the second joint labyrinth game (La2).
Note. adj = FDR adjusted p-values.Lags are measured in seconds.La1 = first joint labyrinth game, La2 = second joint labyrinth game.

Table S6 .
Results of paired sample t-tests comparing synchrony of actual and shuffled pairs for shared positive affect.
Note. adj = FDR adjusted p-values.Lags are measured in seconds.La1 = first joint labyrinth game, La2 = second joint labyrinth game.

Table S7 .
Results of paired sample t-tests comparing synchrony of actual dyads before

Table S8 .
Results of paired sample t-tests comparing synchrony of actual and shuffled pairs after regression of mother's and child's individual positive affect Note.adj = FDR adjusted p-values.Lags are measured in seconds.La1 = first joint labyrinth game, La2 = second joint labyrinth game.

Table S9 .
Results of paired sample t-tests comparing synchrony of actual dyads before

Table S10 .
Results of paired sample t-tests comparing synchrony of actual and shuffled pairs after regression of mother's and child's shared positive affect.

Table S11 .
Results of paired sample t-tests comparing synchrony of actual dyads after