Biology subjects

Nardelli, M.

Publications and source records attributed to Nardelli, M..

3 recordsLinked to original sources

bioRxiv2026

Shared book reading promotes experience-dependent autonomic synchrony in parent-preterm infant dyads

Preterm birth is associated with alterations in early caregiver-infant regulation, with potential consequences for socio-emotional and physiological development. However, the mechanisms through which early interactional experience shapes these processes remain unclear. Here, we tested whether a structured dyadic intervention could modify co-regulatory dynamics across physiological, behavioral, and relational levels. Fifty-four 7-month-old preterm infants and their parents were assigned to either a shared book reading intervention (n = 22) or an active control condition based on a shared building activity (n = 32) and compared with 39 full-term infants. The intervention consisted of an 8-week program of shared book reading, designed to structure parent-infant interaction. Physiological synchrony was assessed at the dyadic level, alongside infants autonomic regulation and cardiovascular signal complexity. Behavioral engagement and parental attachment representations were also evaluated. Results showed that mother-infant physiological synchrony emerged selectively within the interactional context trained by the intervention and only in the intervention group. This context-specific synchrony was accompanied by modulation of vagal activity and increased cardiovascular complexity in preterm infants, consistent with enhanced flexibility of autonomic control. At the behavioral and relational levels, intervention infants showed increased initiating joint attention, while parents reported higher secure attachment. These findings support a model of experience-dependent early synchrony, in which repeated dyadic interaction through shared book reading shapes the coupling between interpersonal coordination and individual physiological regulation. By linking synchrony, autonomic flexibility, and social engagement, this study identifies a mechanism through which early caregiving experience can organize developmental trajectories following prematurity.

developmental biology↗

bioRxiv2026

Interpersonal physiological synchrony: estimation and clinical application to cardiac dynamics of parent-infant dyads

Synchrony is a key mechanism that builds up the foundations of human interactions. Quantifying the level of physiological synchronization that occurs during dyadic exchanges is essential to fully comprehend social phenomena. We present a new index to characterize the coupling of complex physiological dynamics: the optimized Multichannel Complexity Index (opMCI). We validated this approach using synthetic time series of two coupled Henon Maps, with four different coupling levels in unidirectional and bidirectional manners. We demonstrated that the opMCI method allows to effectively discern between all coupling levels. Then, we applied the opMCI metric on heart rate variability data collected from 37 parent-infant dyads, during shared reading and playing activities, in the framework of the Shared Emotional Reading (SHER) project, with the aim of assessing the effects of early intervention in preterm babies. Two groups presented preterm infants: an intervention group, who participated in a two-month shared reading program, and a control group, who practiced shared play activities. A full-term group provided additional control data. The opMCI values were significantly higher for the intervention dyads with respect to the other groups during the shared reading task, showing that an early reading intervention program could increase parent-infant synchrony in preterm babies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/712915v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@22f13forg.highwire.dtl.DTLVardef@c623eorg.highwire.dtl.DTLVardef@10605b5org.highwire.dtl.DTLVardef@60d594_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIInterpersonal physiological synchrony is a fundamental mechanism for the evolutionary path C_LIO_LIAn ad-hoc methodological framework to assess nonlinear cardiac coupling is lacking C_LIO_LIThe opMCI has been shown to be a reliable tool for assessing the degree of synchrony C_LIO_LIEarly shared book reading may increase parent-infant synchrony in a clinical setting C_LI

bioengineering↗

bioRxiv2025

Cardiorespiratory mechanisms triggered during music perception in preterm infants and adults

SHORT-ABSTRACTPreterm newborns autonomic response to dynamic auditory stimuli is poorly understood. To examine how cardiac and respiratory systems adjust their rhythms in response to music, we assessed 18 preterm infants (gestational age 37.73 {+/-} 0.80 weeks) and 19 adults across music listening. Heart rate variability (HRV) dynamics and respiratory sinus arrhythmia (RSA), and cardiorespiratory coupling were analyzed. Both groups showed decreased high-frequency power in HRV during music listening. In preterm infants, RSA increased (p-value = 0.005), possibly suggesting a state of calm alertness, where the infant is physiologically prepared for interaction with environmental stimuli, while adults had decreased RSA (p-value = 0.003) and concomitant increased values of the low frequency/high frequency power ratio, possibly reflecting heightened alertness. While HRV responses to music were similar between preterms and adults, only the investigation of RSA and cardiorespiratory coupling measures revealed the delicate balance of autonomic dynamics in preterm newborns.

physiology↗