Biology subjects

Rozhko, M.

Publications and source records attributed to Rozhko, M..

4 recordsLinked to original sources

bioRxiv2026

Caregiver-infant interactions selectively shape emerging functional connectivity in the neonatal brain

From birth, human infants engage in multi-modal social exchanges with caregivers that involve the coordination of gaze and touch to guide attention and support neurodevelopment. However, little is known about the association between these first interactive experiences and the functional organization of the developing brain during the first postnatal month, a window of remarkable brain growth in humans. We address this gap by combining microanalytic coding of caregiver- infant interactions with task-free functional connectivity (FC), measured using high-density diffuse optical tomography (HD-DOT) in infants homes during the first postnatal month. Task-free FC measures the intrinsic functional organization of the developing brain, shedding light on the early development of neural systems supporting perception, regulation, and social interactions. Infants were assessed up to three times (1 week, 2 weeks, 1 month), enabling characterization of both early FC and its rapid developmental change. Caregiver-infant interactions were associated with both concurrent organization and rapid longitudinal change in FC. Dyadic engagement in the context of face-to-face interaction was associated with the refinement of short-range connectivity and the integration of long-range connectivity particularly between social brain regions, while affectionate touch was associated with general increases in long-distance connectivity. These results demonstrate that caregiving experiences influence the development of the brains functional architecture in the first postnatal month, highlighting a critical window for shaping infant brain function. Significance StatementThe first postnatal weeks are a period of rapid brain development, when the brain may be especially sensitive to experience. A key early experience is social interaction between infants and their caregivers, yet it remains unknown if these interactions influence neonate brain function. By combining observations of caregiver-infant interactions at one month with repeated home-based brain imaging, we show that variations in dyadic engagement and affectionate touch influence how infant brain functional connectivity is organized and develops. These findings highlight the importance of supporting perinatal life and early interactions for infant brain development.

neuroscience↗

bioRxiv2025

Examining Cross-Paradigm fNIRS Brain Activity in Neonates across The Gambia and UK

SignificanceNeonates undergo rapid development, yet the examination of emerging brain markers across paradigms, cognitive domains and diverse global populations remains limited. AimThis study investigated whether brain responses at one-month-of-age could be interrogated across paradigms to offer deeper context-specific insights into neurodevelopment. ApproachFunctional near-infrared spectroscopy (fNIRS) was used to assess frontal and temporal brain responses during natural sleep in 181 Gambian (GM) and 58 UK infants during three auditory paradigms: Social Selectivity, Habituation and Novelty Detection (HaND) and Functional Connectivity (FC). Paradigm-level brain responses were analysed using threshold-free cluster enhancement and cross-paradigm comparisons of individual responses. ResultsAt the group level, both GM and UK infants showed habituation but not novelty responses, higher inter-versus intra-hemispheric connectivity, stronger inter-hemispheric connectivity in temporal regions relative to frontal regions, stronger inter-regional connectivity between right temporal and left frontal regions, and UK infants also showed non-vocal > vocal selectivity. ConclusionsCross-cohort differences in the cross-paradigm analyses suggest context-specific developmental markers are evident within the first month of life and show high individual variability. Cross-paradigm analyses revealed that greater vocal selectivity (UK) was associated with higher inter-hemispheric connectivity, potentially allowing us to identify biomarkers of more mature neurodevelopment within the first weeks of postnatal life.

neuroscience↗

bioRxiv2025

Effect of sleep stages on patterns of fNIRS hemodynamic response to auditory paradigms in one-month-old Gambian and UK infants

SignificanceFunctional near-infrared spectroscopy (fNIRS) has advanced our understanding of early brain development, especially infant responses to social and auditory stimuli. Unlike older children and adults, very young infants are often assessed during natural sleep to reduce movement and ensure sufficient data quality. Yet the impact of sleep stage on fNIRS signals and how it might affect interpretations of early brain activation patterns remains unclear. AimThis study investigates the effect of sleep stages on fNIRS-measured hemodynamic responses to two auditory paradigms across different global populations of one-month-old infants. ApproachIn total, 46 Gambian and 40 UK infants in quiet or active sleep were tested using (1) social selectivity and (2) a habituation and novelty detection paradigms. ResultsIn the UK cohort, active sleep was associated with a stronger initial response and greater habituation compared to quiet sleep. In contrast, Gambian infants in quiet sleep showed more widespread activation and evidence of habituation, while infants in active sleep showed no habituation. No sleep stage effects were observed for response in the social selectivity paradigm in either group. ConclusionsDifferent effects of sleep stages were observed across the two cohorts and paradigms and should be carefully considered in neuroimaging studies.

neuroscience↗

bioRxiv2025

Longitudinal Habituation and Novelty Detection neural responses from infancy to early childhood in The Gambia and UK

As infants and young children learn from and respond to their environment, their development is driven by their ability to filter out irrelevant stimuli and respond to salient stimuli. While sources and types of stimuli vary across cultural contexts, research to understand the neural mechanisms of these behaviors have largely focused on relatively homogeneous populations in high income settings. To address this lack of diverse representation the Brain Imaging for Global health project (BRIGHT) collected longitudinal data in The Gambia (N=204) and the UK (N=61). Here we present results of the Habituation and Novelty Detection (HaND) fNIRS neuroimaging task. Gambian infants showed persistent response suppression (Habituation) at all visits (from 5mo to 60mo) while Novelty Detection was only observed once infants reached 18 and 24mo. In the UK, infants only showed persistent habituation from 5-12mo, while the response was not evident at 18 and 24mo. Furthermore, in contrast to The Gambia, alongside the habituation patterns observed Uk infants showed novelty detection from 5-12mo. This is the first longitudinal description of the HaND response in individuals from different contextual backgrounds across such a broad age range and number of time points, revealing different patterns of specialization in The Gambia and UK. HighlightsO_LIThis is the first characterization of Habituation and Novelty Detection (HaND) responses in infants and young children from contrasting settings across low and high-income countries. C_LIO_LIIn the Gambian cohort, Habituation was typically observed from 5 to 60months; only weak patterns of Novelty Detection were observed at 18 and 24months. C_LIO_LIIn the UK cohort, HaND responses were observed up to 12months of age; but were not evident at 18 and 24months. C_LIO_LIDevelopmental trajectories of HaND responses follow different patterns of specialization from birth to five years of age in individuals living in different contexts. C_LI

neuroscience↗