Biology subjects

Kabdebon, C.

Publications and source records attributed to Kabdebon, C..

8 recordsLinked to original sources

bioRxiv2026

Distinct experience-dependent reorganization of rhythmic syllable tracking in 6-month-old term and preterm infants

Preterm birth is associated with an increased risk of later language difficulties, yet whether and how prematurity alters the brain's ability to track the rhythmic structure of speech has remained understudied. Using EEG, we tracked neural entrainment to delta- and theta-rate syllable sequences produced by the infant's mother or an unfamiliar speaker in term and preterm 6-month-old infants, modeling how oscillatory responses evolved over the course of a testing session. Term infants progressively strengthened frequency-matched delta tuning over bilateral frontal regions; preterm infants did not. This divergence took two distinct forms: a change in frequency selectivity over left frontal channels, where term infants sharpened and preterm infants blurred, and a shift in band weighting in other regions. The frontal delta difference emerged only for the unfamiliar speaker. Preterm birth thus alters how frequency-specific tuning is refined during exposure, identifying a candidate neural pathway with implications for early language learning.

neuroscience↗

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

Simultaneous EEG-fMRI investigation of sound sequence processing in human neonates

The ability to detect sensory regularities and their violations (i.e. deviance) is fundamental for learning and the orientation of attention across the lifespan. This starts from the prenatal period, where the environment is rich in regular patterns and deviations of auditory stimulation which likely provides the basis for the emergence of early learning capacities. Following birth, EEG recordings of brain activity have demonstrated that neonates detect violations of regularity and show a robust mismatch response to deviant auditory stimuli. However, it is unknown how this processing is integrated across wider regions within emergent brain networks. To gain comprehensive insight into both the temporal and spatial properties of the processing underlying sensory deviance detection in the neonatal brain, we acquired simultaneous EEG and fMRI data in sleeping neonates during an auditory oddball paradigm. A mismatch response was identified with EEG when a deviant sound appeared after a sequence of identical sounds but not when a sound was omitted, suggesting encoding of deviances that violated local sequence regularity, but not global sequence structure. Simultaneous fMRI demonstrated engagement of distributed cortical networks during sound sequence processing, encompassing temporal, sensori-motor, and inferior frontal cortices, as well as subcortical regions including the thalamus and hippocampus. Deviance detection was associated with activity in the superior and ventromedial (hippocampus and parahippocampus) parts of the temporal lobe, and the precentral gyrus. Together, these findings suggest that neonatal brain detects deviance in sound sequences through the encoding of local regularities, supported by distinct processing pathways within sensory and limbic systems. These insights help advance our understanding of early auditory learning mechanisms, with implications for understanding how atypical developmental trajectories may emerge in these substrates.

neuroscience↗

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↗

bioRxiv2024

Temporal dynamics and maturation of resting-state activity in preterm infants

By interfering with the normal sequence of mechanisms serving the brain maturation, premature birth and related stress can alter perinatal experiences, with potential long-term consequences on a childs neurodevelopment. The early characterization of brain functioning and maturational changes is thus of critical interest in premature infants who are at high risk of atypical outcomes and could benefit from early diagnosis and dedicated interventions. Using high-density electroencephalography (HD-EEG), we recorded brain activity in extreme and very preterm infants at the equivalent age of pregnancy term (n=43), and longitudinally 2-months later (n=33), compared with full-term born infants (n=14). We characterized the maturation of brain activity by using a dedicated microstate analysis to quantify the spatio-temporal dynamics of the spontaneous transient network activity while controlling for vigilance states. The comparison of premature and full-term infants first showed slower dynamics as well as altered spatio-temporal properties of brain activity in preterm infants. Maturation of functional networks between term-equivalent age and 2 months later in preterms was linked to the emergence of faster dynamics, manifested in part by shorter duration of microstates, as well as an evolution in the spatial organization of the dominant microstates. The inter-individual differences in the temporal dynamics of brain activity at term-equivalent age were further impacted by sex (with slower microstate dynamics in boys) and by gestational age at birth for some microstate dynamics but not by other considered risk factors. This study highlights the potential of the microstate approach to reveal maturational properties of the emerging brain network activity in premature infants.

neuroscience↗

bioRxiv2019

Anatomo-functional correlates of auditory development in infancy

Brain development incorporates several intermingled mechanisms throughout infancy leading to intense and asynchronous maturation across cerebral networks and functional modalities. Combining electroencephalography (EEG) and diffusion magnetic resonance imaging (MRI), previous studies in the visual modality showed that the functional maturation of the event-related potentials (ERP) during the first postnatal semester relates to structural changes in the corresponding white matter pathways. Here we aimed to investigate similar issues in the auditory modality. We measured ERPs to syllables in 1-to 6-month-old infants and analyzed them in relation with the maturational properties of underlying neural substrates measured with diffusion tensor imaging (DTI). We first observed a decrease in the latency of the auditory P2, and a decrease of diffusivities in the auditory tracts and perisylvian regions with age. Secondly, we highlighted some of the early functional and structural substrates of lateralization. Contralateral responses to monoaural syllables were stronger and faster than ipsilateral responses, particularly in the left hemisphere. Besides, the acoustic radiations, arcuate fasciculus, middle temporal and angular gyri showed DTI asymmetries with a more complex and advanced microstructure in the left hemisphere, whereas the reverse was observed for the inferior frontal and superior temporal gyri. Finally, after accounting for the age-related variance, we correlated the inter-individual variability in P2 responses and in the microstructural properties of callosal fibers and inferior frontal regions. This study combining dedicated EEG and MRI approaches in infants highlights the complex relation between the functional responses to auditory stimuli and the maturational properties of the corresponding neural network.

neuroscience↗

bioRxiv2018

A precursor of reading capacity? 3-month-old infants easily learn to pair a phoneme with a visual shape

Being aware of the phonemes that compose syllables is difficult without having learned to read an alphabetic script, a skill generally acquired around 5 to 7 years of age. Nevertheless, preverbal infants are particularly good at discriminating syllables that differ by a single phoneme. Do they perceive syllables as a whole unit or can they become aware of the underlying phonemes if their attention is attracted to the relevant level of analysis? We trained 3-month-old infants to pair two consonants, co-articulated with different vowels, with two visual shapes. Using event-related potentials, we show that infants generalize the learned associations to new syllables with respect to a familiarization phase. The systematic pairing of a visual label with a phonetic category is thus easy to learn, suggesting that the main process underlying reading (i.e., grapheme-phoneme pairing) is grounded in the early faculties of the human linguistic system.

neuroscience↗

bioRxiv2018

Symbolic labelling in 5-month-old human infants

Humans naturally entertain complex representations of the world based on various symbolic systems, from natural language to mathematical or musical notation. Above and beyond mere perceptual representations, the adult human mind can recode sensory inputs into abstract symbolic representations that can be internally manipulated and projected back onto the external world. However, the ontogeny of this striking ability remains controversial: Are children progressively acquiring symbolic representations through language acquisition, or are mental representations symbolic from the very beginning, language learning consisting in mapping mental symbols onto public symbols? Using high-density electroencephalography, we show here that preverbal infants can form mental representations that feature symbolic attributes. In three experiments, a total of 150 five month-olds were exposed to triplet words characterized by their abstract syllabic structure (AAB/ABA/ABB) consistently followed by an arbitrary label. Subsequently, incongruent structure-label pairings evoked a late violation-of-expectations signal, whereas congruent pairings induced an early priming effect. Importantly, the late surprise response was recorded for incongruent pairs even when the pairing order was reversed at test (i.e. labels preceding structure). Our results indicate that first, far beyond habituation/dishabituation, preverbal infants are able to recode sensory inputs, into abstract mental representations to which arbitrary labels can be flexibly assigned. Second, we demonstrate that, beyond conditioned associations, this mapping is instantly bidirectional. These findings buttress the hypothesis of symbolic representations in preverbal infants, which may serve as a foundation for our distinctively human learning abilities.\n\nSignificance StatementSymbolic systems provide a powerful tool for efficiently re-describing the world into operable mental variables that, in turn, become objects of cognitive manipulation. However, is this ability tied to mastering language? Using an associative learning task in preverbal infants, we show that 5 month-olds can re-describe percepts into abstract mental variables that can be associated with arbitrary labels, well before they produce their first words. Importantly, we show that, beyond associative learning, they readily inferred a bidirectional mapping between the re-described representations and the associated labels, a capacity that animals do not spontaneously exhibit. Human cognitive success might be rooted in such abstract recoding which is no longer sensitive to local variations, thus alleviating cognitive load, and ultimately facilitating learning.

neuroscience↗