Biology subjects

Filippa, M.

Publications and source records attributed to Filippa, M..

8 recordsLinked to original sources

bioRxiv2026

Delta rhythm and voice familiarity organize neural entrainment in the infant brain

The delta frequency band (~0.5-3.5 Hz) represents a phylogenetically conserved tempo of biological communication, and neural entrainment to this timescale would be a key mechanism through which the brain might generate temporal predictions. While entrainment at different levels has been characterized in adults, the mechanisms of auditory temporal prediction remain poorly studied across developmental trajectories, particularly regarding the roles of stimulus rhythmicity, frequency specificity, and voice familiarity. Using high-density EEG, we examined neural entrainment in thirty 6-month-old infants exposed to vocally rhythmic syllables produced by their mother or a stranger at delta (2 Hz) or theta (4 Hz) rates, as well as a non-rhythmic control. Auditory temporal regularity elicited a broad frontotemporal entrainment response. Critically, delta-band entrainment was frequency-specific across frontal and temporal clusters, with right-frontal selectivity progressively strengthening throughout the entrainment period as expected if this region actively refines a temporal model of the input rather than passively resonating to it; no significant theta-band specificity was observed. Entrainment was further shaped by voice familiarity: the left temporal cortex entrained selectively to the mother's voice, whereas the right frontal cluster responded selectively to the stranger's voice. This is consistent with an implementation in which familiarity-based processing within mid-temporal language-related regions interfaces with novelty-sensitive frontal mechanisms, and reflects the ongoing updating of internal predictive models rather than passive sensory registration. The co-occurrence of frequency-specific delta entrainment and experience-dependent hemispheric asymmetries reveals a neural functional network for hierarchical temporal predictions, shaped by early auditory experience and already in place at 6 months.

neuroscience↗

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

Acoustic Features of Emotional Expression in Preverbal Infant Vocalizations

The musicality of human communication before the onset of words enables mutual interaction from early infancy and lays the foundation for language development. The present study investigated the development of infants emotional vocalizations across the first year of life, with a specific focus on their acoustic properties. Analyses revealed systematic age-related changes in acoustic features, with pronounced shifts in pitch height, spectral clarity, and formant stability occurring between 3-6 and 6-9 months. These findings mark the second half of the first year as a key milestone in the development of vocal communication. Linear discriminant analysis confirmed improved age classification beyond this stage. Emotional valence was encoded in distinct acoustic profiles, particularly involving spectral energy, pitch, vocal intensity, and resonance. Negative vocalizations, especially in younger infants, exhibited consistently higher pitch and intensity, along with stable acoustic signatures over time, suggesting their function as early, distinct affective signals. Valence-specific developmental trajectories were also identified. While formant frequency changes typically clustered around the 6-month age, an earlier shift was evident in positive vocalizations, adding nuance to general developmental trends. Taken together, these findings challenge the notion of full emotional neutrality in preverbal vocalizations and suggest that emotional valence is partially encoded in stable acoustic parameters. Such cues may complement contextual information in supporting caregivers interpretation of infants emotional states. This work contributes to understanding how functional flexibility emerges through the developmental tuning of prosody and further calls for research into whether adults can reliably decode emotion from vocal signals alone, shedding light on the perceptual foundations of early social communication.

developmental biology↗

bioRxiv2025

The origins of time: a systematic review of the neural signatures of temporal prediction in infancy

From birth, individuals interpersonal dimension is underpinned by progressive learning of social interaction rules, their variations rooted in the temporal prediction of sensory events, and the inferences made about the organization of the social world. How this dimension is progressively structured during infancy and articulated at the neural level is a critical question for cognitive and affective neurosciences. This systematic review aims to define the neural signatures of temporal prediction in newborns and infants and to discuss them in the context of the development of proximal cognitive and affective neural functions. Eight peer-reviewed studies were included, with 228 infants from birth to 9 months of age. Studies have shown that the neural signatures of temporal prediction in infants exhibit a broad cerebral localization, including the anterior and medial parts of the brain, particularly in the frontal and central areas. Temporal prediction mechanisms emerge before birth and range from early sensory-driven responses to more complex top-down processes within the first year of life. While current data do not support a clear longitudinal interpretation, these abilities appear to be shaped by both biological predispositions and experiential factors, with interactive rhythmic and musical activities potentially contributing to their development.

neuroscience↗

bioRxiv2025

Maternal singing synchronizes the preterm infants' brain

Singing to infants is a universal human practice that has beneficial effects on infants cognitive and affective development. Children born preterm have impaired brain development, and their perception of maternal speech is known to be affected by the atypical hospital auditory environment. Understanding how preterm infants perceive maternal singing is of critical importance, yet it remains largely unexplored. Using high-density EEG, we examined neural responses to the same melody presented through maternal singing, stranger singing, and instrument, and compared the responses in 12 preterm infants. Moreover, to examine their processing of spatialisation, auditory stimuli were presented under monaural and binaural conditions. Preterm newborns are able to discriminate the same melody when sung by their mother, a stranger, or played by an instrument. When presented monaurally, the mothers singing voice enhances widespread brain synchrony across the entire scalp. In contrast, this synchrony diminishes with binaural spatialization. These findings suggest that maternal singing constitutes a highly salient auditory stimulus for preterm newborns, eliciting a distinct neural signature. Given that brain synchrony is a critical component of healthy brain function and development, harnessing maternal singing may offer a promising, natural intervention to support neurodevelopment--particularly in vulnerable populations such as preterm infants.

neuroscience↗

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↗

bioRxiv2022

Preterm infants voice processing is mediated by voice familiarity

To understand the consequences of prematurity on language perception it is fundamental to determine how atypical early sensory experience affects brain development. To date the neural oscillatory correlates in the time-frequency domain of voice processing as a function of atypical early sensory experience, as after premature birth, remain elusive. At term equivalent age, ten preterm and ten full-term newborns underwent high-density EEG recordings during mother or stranger speech presentation, presented in the forward (naturalistic) or backward order. A general group effect terms > preterms for the naturalistic mothers voice is evident in the theta frequency band in the left temporal area, where only full-term newborns showed an increased activity for the mothers voice, whereas preterm infants showed significant activation for stranger naturalistic speech. Similarly, a significant group contrast in the low and high theta in the right temporal regions indicates higher activations for the strangers speech in preterms. Finally, only full-term newborns presented a late gamma band increase for the maternal naturalistic speech, indicating a more mature brain response. The current study based on neural time-frequency patterns, demonstrates that preterm infants lack selective brain responses to mothers naturalistic voice typical for full-term newborns, whereas preterms are selectively responsive to stranger voices in both temporal hemispheres.

neuroscience↗