Abstract
<p>The preschool years are crucial for school readiness, with the child-parent attachment relationship providing a foundational context for skill acquisition as part of this transition. Advances in social neuroscience suggest that interpersonal neural synchrony (INS) represents a valuable index of interaction and relationship quality. We examined whether parent-child INS during a parent-guided learning task was associated with observed parental interaction behavior and narrative child attachment representations. INS in bilateral frontal and temporoparietal cortex was assessed using functional near-infrared spectroscopy (fNIRS) hyperscanning in ninety-three parents (51 fathers) and their biological children (aged 5-6 years, 48 girls) while parents guided children through cognitive exercises. Parental interaction behavior was assessed using video-coded NICHD sensitivity scales, and children’s attachment representations were indexed by narrative coherence using the Picture Story Stem Battery (PSSB). Results revealed specific region-dependent functional patterns. A positive correlation between parental respect for autonomy and quality of assistance with bilateral prefrontal INS possibly reflecting cognitive scaffolding. Furthermore, INS in the left prefrontal cortex positively correlated with child task performance and mediated the relationship between parental assistance and task success. In contrast, temporoparietal INS, particularly in mother-child dyads, possibly reflected relational and regulatory processes. While child attachment security positively correlated with right temporoparietal INS, maternal hostility negatively correlated with bilateral temporoparietal INS. Taken together, our findings suggest that INS in the prefrontal and temporoparietal cortex may serve as a differential neurobiological correlate of dyadic coordination, possibly capturing both the relational quality of the child-parent attachment bond and the efficacy of parental scaffolding in supporting early learning.</p>