Neural synchrony in mother-child conversation: Exploring the role of conversation patterns

Abstract

Conversations are an essential form of communication in daily family life. Specific patterns of caregiver-child conversations have been linked to children's socio-cognitive development and child-relationship quality beyond the immediate family environment. Recently, interpersonal neural synchronization has been proposed as a neural mechanism supporting conversation. Here, we present a functional near-infrared spectroscopy (fNIRS) hyperscanning study looking at the temporal dynamics of neural synchrony during mother-child conversation. Preschoolers (20 boys and 20 girls, M age 5;07 years) and their mothers (M age 36.37 years) were tested simultaneously with fNIRS hyperscanning while engaging in a free verbal conversation lasting for 4 min. Neural synchrony (using wavelet transform coherence analysis) was assessed over time. Furthermore, each conversational turn was coded for conversation patterns comprising turn-taking, relevance, contingency and intrusiveness. Results from linear mixed-effects modeling revealed that turn-taking, but not relevance, contingency or intrusiveness predicted neural synchronization during the conversation over time. Results are discussed to point out possible variables affecting parent-child conversation quality and the potential functional role of interpersonal neural synchronization for parent-child conversation.

Keywords: conversation; functional near-infrared spectroscopy; hyperscanning; mother–child interaction; neural synchrony; turn-taking.

Fig. 1

(A) Study set-up during the free verbal conversation task. (B) Cap configuration. Red circles mark sources and blue circles mark detectors. Numbers (1–16) mark measurement channels between sources and detectors and black circles mark EEG 10–20 channel positions for orientation. The top graphic shows the left hemisphere and the bottom graphic shows the right hemisphere.

Fig. 2

WTC values were calculated by averaging over the frequency range of interest (6–16 period seconds—~0.06 Hz—0.15 Hz—on the y-axis) for the entire experimental procedure and epochs of 30 s over the 4 min of the conversation condition (indicated by one square along the x-axis [time in seconds]). Coherence values ranged from 0 to 1 (as indicated by the color bar) and all coherence values outside the cone of interest demarcation were excluded from analyses.

Fig. 3

3D-plot depicting the interaction between the number of turns taken (x-axis) and time in epochs of 30 s (z-axis) on neural synchrony (WTC; y-axis). The horizontal plane depicts estimates of neural synchrony extracted from the linear mixed-effects modeling. Black and white dots show the observed value of each dyad in each channel either above their model estimate (black) or below their model estimate (white). Larger dots indicate that a higher number of observations were summarized within the dot, while smaller dots indicate fewer observations. Overall, the plot depicts that more turn-taking was linked to higher neural synchronization towards the end of the conversation.