Hyperscanning Studies on Interbrain Synchrony and Child Development: A Narrative Review

Multimodal analysis of mother-child interaction using hyperscanning and diffusion maps

The current work aims to reveal mother-child synchronization patterns using several interaction modalities and combining them using the diffusion maps method. Twenty-two Hebrew-speaking toddlers (ages = 33 ± 5.38 months, 17 males) and their mothers (ages = 35 ± 5.79 years) participated in two interaction conditions while data was collected from several modalities, i.e. EEG, joint attention (measured through video coding of looking behavior), and motion analysis. Dimension reduction and data fusion of these modalities were performed using diffusion maps to enable a comprehensive assessment of mother-child synchronization dynamics. This multimodal approach allows better characterization of mother-child interaction and examining the associations between interaction patterns and maternal parenting style and their importance to the child's long-term language abilities.

2-Brain Regulation for Improved Neuroprotection during Early Development (2-BRAINED): a translational hyperscanning research project

Introduction

Very preterm (VPT) birth is a major risk condition for child development and parental wellbeing, mainly due to multiple sources of stress (e.g., separation and pain exposure) during the neonatal intensive care unit (NICU) stay. Early video-feedback (VF) interventions proved effective in promoting VOT infants' development and parental wellbeing. Electroencephalography (EEG) hyperscanning allows the assessment of brain-to-brain co-regulation during live interaction between infants and parents, offering promising insights into the mechanisms behind the interactive benefits of early VF interventions.

Goals

This study aimed to compare indices of brain-to-brain co-regulation between dyads of full-term (FT) and VPT infants interacting with their mothers and investigate the effect of an early post-discharge VF intervention on the brain-to-brain co-regulation indices of VPT dyads.

Methods and analysis

VPT and FT dyads will be enrolled at birth, and the former will be randomly allocated to one of two arms: VF intervention or care as usual. Short-term effectiveness will be assessed through ratings of mother-infant interaction videotaped before and after the VF intervention or care as usual. Mothers of VPT and FT infants will report on their mental state, parenting stress and bonding, and infant temperament and sensory profile at 3 and 6 months (corrected age, CA). At 9 months CA, all dyads will participate in a lab-based EEG-hyperscanning paradigm to assess brain-to-brain co-regulation through phase-locking value (PLV) and other explorative indices.

Ethics and dissemination

This study was funded by the Italian Ministry of Health and received approval by the Ethics Committee of Pavia (Italy) and participating hospitals. Research findings will be reported in scientific publications, presented at international conferences, and disseminated to the general public.

Study registration number

GR-2021-12375213 (Italian Ministry of Health registry).

Mother-Infant Dyadic Neural Synchrony Measured Using EEG Hyperscanning and Validated Using Behavioral Measures

BACKGROUND/OBJECTIVE

Greater parent-infant synchrony is associated with improved child outcomes. Behavioral measures of synchrony are still developing in young infants; thus, researchers need tools to quantify synchrony between parents and their young infants. We examined parent-infant neural synchrony measured using dual EEG hyperscanning and associations between neural synchrony, infant behavioral measures of synchrony, and maternal bondedness and depression.

METHODS

Our prospective cohort study included mother-infant dyads at 2-4 months of age. We collected time-locked dual EEG recordings of mother and infant and simultaneous video-recordings during a scaffolded interaction where the mother sequentially layered sensory modalities to the interaction. Neural synchrony measured using EEG hyperscanning was analyzed using the circular correlation coefficient (CCorr), infant behavioral synchrony was measured using the validated Welch Emotional Connection Screen (WECS) scores, and maternal bondedness and depression were measured using standardized questionnaires.

RESULTS

Our study included n = 47 dyads. Dyadic CCorr increased across the interaction as the mother added tactile stimulation to visual stimulation. We also found associations between behavioral and neural measures of dyadic synchrony such that infants with higher scores on behavioral measures of emotional connection on the WECS showed greater increases in CCorr indicative of dyadic synchrony with their mother across this interaction. We found no associations between neural synchrony and maternal bondedness or depression.

CONCLUSION

These findings support the construct validity of mother-infant dyadic neural synchrony measured using EEG hyperscanning and analyzed using CCorr. Opportunities for future research on quantification of neural synchrony between parents and young infants abound.

Interpersonal neural synchronization during social interactions in close relationships: A systematic review and meta-analysis of fNIRS hyperscanning studies

In recent years, researchers have used hyperscanning techniques to explore how brains interact during various human activities. These studies have revealed a phenomenon called interpersonal neural synchronization (INS), but little research has focused on the overall effect of INS in close relationships. To address this gap, this study aims to synthesize and analyze the existing literature on INS during social interactions in close relationships. We conducted a meta-analysis of 17 functional near-infrared spectroscopy (fNIRS) hyperscanning studies involving 1149 dyads participants, including romantic couples and parent-child dyads. The results revealed robust and consistent INS in the frontal, temporal, and parietal regions of the brain and found similar INS patterns in couples and parent-child studies, providing solid empirical evidence for the attachment theory. Moreover, the age of children and brain areas were significant predictors of the effect size in parent-child research. The developmental stage of children and the mismatched development of brain structures might be the crucial factors for the difference in neural performance in social and cognitive behaviors in parent-child dyads.

Mothers and fathers show different neural synchrony with their children during shared experiences

Parent-child shared experiences has an important influence on social development in children although contributions of mothers and fathers may differ. Neural synchronicity occurs between mothers and fathers and their children during social interactions but it is unclear whether they differ in this respect. We used data from simultaneous fNIRS hyperscanning in mothers (n = 33) and fathers (n = 29) and their children (3-4 years) to determine different patterns and strengths of neural synchronization in the frontal cortex during co-viewing of videos or free-play. Mothers showed greater synchrony with child than fathers during passive viewing of videos and the synchronization was positively associated with video complexity and negatively associated with parental stress. During play interactions, mothers showed more controlling behaviors over their child and greater evidence for joint gaze and joint imitation play with child whereas fathers spent more time gazing at other things. In addition, different aspects of child communication promoted neural synchrony between mothers and fathers and child during active play interactions. Overall, our findings indicate greater neural and behavioral synchrony between mothers than fathers and young children during passive or active shared experiences, although for both it was weakened by parental distress and child difficulty.