INTER-BRAIN SYNCHRONY IN MOTHER-INFANT DYADS DURING FACE-TO-FACE STILL-FACE INTERACTIONS: An EEG hyperscanning pilot study

In developmental science, prior research has demonstrated that caregiver-infant dyads commonly exhibit biobehavioral synchrony during their interactions. Within this realm, the Still-Face procedure (SFP) developed by Tronick has been extensively utilized to explore how dyads can recover disrupted interactions and reestablish their connection. The introduction of hyperscanning technology has opened avenues to investigate inter-brain synchrony (IBS) dynamics between caregivers and infants, although specific focus on IBS during the SFP is lacking in existing literature. This pilot study utilized EEG hyperscanning to examine IBS in sixteen mother-infant pairs participating in the SFP. The Phase Locking Value (PLV), as a measure of phase synchrony, was calculated during the Play and Reunion episodes in theta (4-7Hz) and alpha (6-9Hz) bands, and changes across these episodes were evaluated using repeated-measure ANOVAs. The results indicate that there is no notable discrepancy in inter-brain Synchrony (IBS) between caregivers and infants during the Play and Reunion episodes in both theta and alpha frequency bands. Nonetheless, our data reveals a meaningful interaction between Episode and Location specifically in the theta frequency band. The different theta patterns in the Play and Reunion episodes suggest that disruption of face-to-face interaction may have a deleterious effect on both biobehavioural and inter-brain synchrony in mother-infant dyads.