Biology subjects

Kurth, S.

Publications and source records attributed to Kurth, S..

15 recordsLinked to original sources

bioRxiv2026

REM Sleep Iota Oscillations Across the Lifespan

Iota oscillations are a newly discovered marker of wakefulness and rapid eye movement (REM) sleep. So far, iota in REM sleep has only been reported in the surface electroencephalography (EEG) of a small sample of young adults and in intracranial recordings of epileptic patients. Here, we investigated the presence of these oscillations in a large dataset (N=937) of high-density sleep EEG recordings from individuals 7 to 70 years old. We found that iota spectral peaks during REM sleep were between 25 and 40 Hz, slightly faster than in wake (25-35 Hz). Iota power was significantly associated with REM sleep architecture, increasing with both REM duration and across progressive sleep cycles. Iota peaks were observed in individuals of all ages, although the prevalence decreased gradually with age, from 88% in children to 44% in older adults. Most iota spectral peak properties (frequency, amplitude, timing, topography) likewise shifted with age. The most striking effect, however, was in bandwidth, such that children had narrow iota peaks, older adults had broad iota peaks, and 20-30 year olds could have either. It remains unclear whether narrowband and broadband iota are functionally equivalent. On shorter time scales (< 1 year), iota properties remained stable across measurements. Analyses of a separate dataset of monozygotic and dizygotic twins revealed high heritability of all iota peak properties except bandwidth. Overall, these results establish iota as a genetically determined trait-like marker of REM sleep with unique age-related changes. Iota oscillations open new avenues to investigate the interaction between sleep, genetics, development, and aging.

neuroscience↗

bioRxiv2025

Charting infant sleep cycle development using actigraphy: Longitudinal evidence for cycle lengthening within the first year of life from 35,000 hours of sleep

Sleep is marked by ultradian cycles, coinciding with the alternation of rapid eye movement (REM) and non-rapid eye movement sleep (NREM). These sleep cycles are a striking feature exhibited from infancy through adulthood, yet their underlying mechanisms and functional relevance remain elusive, calling for large-scale longitudinal studies. Here we leverage Locomotor Inactivity During Sleep (LIDS), previously established in adults as an accessible means to track sleep cycles, to chart ultradian sleep cycle dynamics within the first year of life at scale. Specifically, we analyzed > 35, 000 hours of sleep from a longitudinal dataset of 152 infants with 10 days of actigraphy at 3, 6, and 12 months of age. Using advanced signal processing techniques, we demonstrate the existence of rhythmic patterns in LIDS in infants with a cycle length of[~] 60 minutes. Cycles were not only shorter in infants than parents (- 11.8 min, 95% C.I. [- 13.8, - 9.8]) but also increased by[~] 10 min from 3 to 12 months of age, mirroring previous results in smaller samples for NREM-REM sleep cycles. This increase was found to be partially mediated by an increase in sleep bout duration with age (+1.0 min/h, [+0.9, +1.2]). Longer cycles were also found in infants still breastfed at 12 months (+2.5 min [+0.4, +4.5]) and their breastfeeding mothers (+6.7 min [+0.5, +12.9]). We also explored variations in non-rhythmic LIDS patterns in relation to endogenous and exogenous factors. Overall, our results provide evidence of a link between rhythmic patterns in limb inactivity and sleep cycles in infancy, underscoring the potential of studying these in large-scale population cohorts for developmental and health outcomes.

physiology↗

bioRxiv2025

The gut microbiota and sleep in infants: a focus on diurnal rhythmicity patterns

Emerging evidence supports a bidirectional relationship between the gut microbiome and sleep, partly mediated by the microbiota-gut-brain axis. Circadian rhythms appear to influence early developmental processes and may play a role in shaping this relationship. While infancy is a critical window for both gut microbiota establishment and the maturation of sleep regulation, the role of gut bacteria in modulating infant sleep remains poorly understood. In this longitudinal study, we performed continuous within-subject sampling (monitoring across 48 hours) in 20 infants at 2, 4, and 6 months of age to examine associations between the establishment of gut microbiota and sleep patterns. We hypothesized that microbial diversity and sleep rhythmicity would be linked across both short (diurnal) and long (monthly) time scales. Gut microbiota profiles were characterized using 16S rRNA gene sequencing; gut melatonin concentrations were measured; and sleep metrics were quantified through wearable actimetry, parent-reported 24-hour sleep diaries, and the Brief Infant Sleep Questionnaire (BISQ). Parents additionally completed the Baby Care Questionnaire (BCQ), assessing parenting style, and the Ages and Stages Questionnaire (ASQ), evaluating infant behavioral development. In some infants, alpha diversity followed diurnal rhythmic patterns. Although bacterial rhythmicity was not significantly associated with sleep rhythmicity, as quantified with the Circadian Function Index, infants with higher alpha diversity had more robust sleep rhythmicity ({beta}Faith PD= 0.0721, SE = 0.0337). Infant age emerged as the strongest predictor of both gut microbiota diversity (observed features: {beta}age = 0.101, SE = 0.0172) and gut melatonin concentrations ({beta}age = 0.638, SE = 0.162). For the same age, gut microbiota temporal volatility - an indicator for bacterial community instability - was not associated with sleep patterns. This study demonstrates promising short- and long-term links between gut microbiota diversity and sleep-wake rhythm maturation in infancy. Further research is needed to elucidate the mechanistic role of the gut microbiome in sleep development.

microbiology↗

bioRxiv2025

Stool Dynamics and the Developing Gut Microbiome During Infancy

The infant gut microbiome is a dynamic ecosystem that plays a crucial role in early development, influences immune system maturation, and overall health. Recent insights reveal that the gut microbiota undergoes changes across the 24-h day, raising the possibility that it may act as "zeitgeber", helping to regulate the hosts sleep-wake organisation. Despite its importance, timing factors influencing microbiome composition are poorly understood, limiting its use as a health predictor. This study investigates the relationship between stool dynamics (interval since last defecation, collection time of the sample), sleep pressure (interval since last sleep), meal timing and the composition of the gut microbiome. Stool samples from 198 healthy infants, aged 3 to 31 months, were analysed to assess microbial diversity, richness evenness, and abundance. Our findings reveal that longer intervals since the last bowel movement are associated with increased microbial diversity, evenness, and richness. Stool timing is associated with shifts in microbial composition, especially in younger infants, indicating that diurnal microbial fluctuations may become more stable as infants mature. We found that longer periods of wakefulness were associated with increased microbial diversity in early infancy, although this effect appeared to diminish with age. Feeding schedules appeared to have a limited effect on the gut microbiome. Longer fasting before sampling showed no significant associations with most microbial parameters, except for a positive association with microbial richness. At the phylum level, results indicate that infant gut microbial composition is influenced by behaviour and physiology. Longer intervals between bowel movements were associated with shifts in bacterial abundance, with Proteobacteria decreasing and Actinobacteria increasing. Stool timing and meal timing also affected microbial diversity: later sampling times showed higher Actinobacteria levels, and longer fasting was associated with reduced Bacteroidetes. Sleep pressure showed a trend effect with Firmicutes displaying a slight decrease in infants who had been awake longer. Our findings underscore the importance of time-based factors on infant gut microbiome composition.

systems biology↗

bioRxiv2025

Tracing infant sleep neurophysiology longitudinally from 3 to 6 months: EEG insights into brain development

1.Sleep is critical for brain plasticity during early development, yet the individual maturation of sleep neurophysiology in infancy remains poorly characterized. In particular, slow wave activity (SWA) has emerged as a key marker of both cortical maturation and experience-dependent plasticity. Understanding the regional dynamics of sleep neurophysiology early in life could yield critical insights into neurodevelopmental health. We conducted a longitudinal high-density EEG study in 11 healthy infants (3-6 months) assessing non-rapid eye movement (NREM) sleep. We analyzed the maturation of SWA (0.75-4.25 Hz), theta power (4.5-7.5 Hz), and sigma power (9.75-14.75 Hz) across scalp regions and examined their association with behavioral development. From 3 to 6 months, SWA increased maximally in occipital regions, while theta power exhibited a global increase. Sigma power, initially concentrated centrally, dispersed towards frontal regions. Greater power increases over frontal regions correlated with higher motor (theta) and personal-social skill scores (sigma) at 6 months. These findings establish a framework for typical infant sleep EEG maturation, highlighting frequency-specific and regionally distinct developmental patterns. This study provides the first longitudinal evidence that early changes in sleep EEG topography reflect individual developmental trajectories, supporting its utility as a non-invasive and yet precise biomarker for early identification of atypical neurodevelopment at preverbal ages.

neuroscience↗

bioRxiv2025

The Infraslow Fluctuation of Sigma Power During Sleep in Young Individuals with Schizophrenia

A reduction in sleep spindles, a major electrophysiological characteristic of Non-Rapid Eye Movement sleep, has been suggested as a potential biomarker of schizophrenia. While research has primarily focused on the spindle quantity, recent studies have begun to explore their temporal dynamics throughout the night. In healthy individuals, sleep spindles fluctuate on an infraslow [~]50-second timescale, alternating between phases of high and low spindle activity. This fluctuation is referred to as the infraslow fluctuation of sigma power (ISFS), which is modulated by noradrenergic activity from the locus coeruleus and linked to the organization of arousal and memory reactivation processes during sleep. Given the known deficit in sleep spindles, dysregulation of noradrenergic activity, and impairments in sleep maintenance and memory in schizophrenia, this study investigates the ISFS in sleep electroencephalography data from individuals with either Childhood-Onset Schizophrenia (COS; N = 17) or Early-Onset Schizophrenia (EOS; N = 11), aged 9 to 21 years, alongside age- and sex-matched healthy controls (N = 56). The presence and strength of the ISFS were reduced in both COS and EOS groups compared to controls, particularly in central-parietal electrodes. No significant differences in these features of the ISFS were found between the two clinical groups, despite group differences in sleep spindle density and clinical characteristics. These findings suggest that the ISFS is observable but reduced in young patients with schizophrenia and support the notion that the timing of sleep spindles may inform pathomechanistic models of the disorder, as well as future diagnostic approaches and interventions.

neuroscience↗

bioRxiv2025

Identification and proteomic profiling of CD90+ small EVs using a refined immunocapture separation approach targeting stromal-derived EV subpopulations in synovial fluid of arthritis patients

Extracellular vesicles (EVs) have emerged as essential drivers in disease progression and promising biomarkers across various disease conditions, including autoimmune diseases such as rheumatoid arthritis (RA). RA is characterized by chronic inflammation driven by patient-specific cellular sub-phenotypes within the synovium. Since EVs reflect their cellular origin and are detectable in biofluids like synovial fluid, they offer a promising alternative for novel biomarker discovery or diagnostics in arthritis, potentially reducing the need for invasive tissue biopsies. However, the inherent complexity, viscosity and extracellular matrix (ECM) composition of synovial fluid pose significant challenges for efficient EV isolation. Moreover, most previous studies have focused on heterogenous bulk EV populations, neglecting the diverse EV subsets present in patient biofluids. To address these challenges, we established a novel immunocapture-based separation method, that selectively targets and isolates cell type-specific EV subpopulation from the heterogenous EV pool present in synovial fluid of arthritis patients. As a proof-of-concept approach, we targeted a stromal-derived EV population by leveraging the fibroblast-associated surface marker CD90/THY1, representing a subset of synovial fibroblasts implicated as important drivers in synovitis and chronic inflammation in RA. Western Blot and data independent acquisition (DIA) liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) proteomic analysis of immunocaptured CD90+ EVs isolated from cultured primary synovial fibroblasts and synovial fluid of arthritis patients, confirmed the successful separation of stromal vs a myeloid/lymphoid EV populations. The in-depth proteomic profiling of synovial fluid EVs offers unprecedented insights into EV heterogeneity in arthritis. This analysis enables the classification of cell-type associated EV subsets and the identification of novel EV markers for future immunocapture-based EV separation strategies. Our refined fit-for-purpose EV separation approach, coupled to in depth proteomic profiling, provides a powerful tool to identify disease-relevant EV subpopulations and novel biomarker candidates in synovial fluid, facilitating advances in arthritis diagnostics and personalized medicine

immunology↗

bioRxiv2025

Rhythms of Early Life: Gut Microbiota Rhythmicity and Circadian Maturation in infants

BackgroundThe human gut microbiota undergoes daily fluctuations, yet its interaction with sleep-wake patterns during infancy remains largely uncharted. This study aims to elucidate the relationship between gut microbiota rhythmicity and the development of sleep patterns in infants over the first year of life. We continuously monitored 162 healthy infants across multiple days at 3, 6, and 12 months of age using ankle actigraphy and 24-hour diaries. The Circadian Function Index (CFI) was computed as a proxy for sleep-wake rhythm maturation. Stool samples were collected to profile gut microbiota taxa composition via 16S rRNA gene amplicon sequencing, and microbial oscillations were assessed through sine and cosine fitting to detect 24-hour patterns. ResultsOur findings revealed that the relative abundance of bacterial taxa exhibited rhythmic patterns, with 26 zOTUs (1.74%) following a sine pattern and 100 zOTUs (6.69%) displaying cosine rhythmicity. Cosine rhythmicity became more pronounced with age, showing strong maturation: 7 zOTUs at 3 months, 2 zOTUs at 6 months, and 86 zOTUs at 12 months. Notably, 105 zOTUs (7.02%) were associated with CFI, demonstrating a significant relationship between gut microbiota rhythms and sleep development. Among these, 27 zOTUs with sine dynamics and 96 zOTUs with cosine dynamics were linked to CFI, with this association strengthening as infants aged. ConclusionsThese results highlight the increasing synchronization between gut microbiota rhythmicity and sleep-wake cycles during infancy, pointing to a critical window for potential health interventions. This novel observation, previously reported in rodents and adults, underscores the role of gut microbiota in early human development, offering new avenues for enhancing developmental outcomes through targeted interventions.

developmental biology↗

bioRxiv2024

From womb to crib: How fetal activity patterns in utero reveal postnatal sleep behavior

ImportanceThe human circadian system, a critical biological mechanism governing the sleep-wake cycle, begins to oscillate before birth. Distinct fetal behavioral states have been described using short-duration ultrasound recordings, but the alignment of fetal activity with day and night cycles (i.e., diurnal rhythms) remains poorly understood due to the lack of long-term monitoring. Accordingly, a substantial knowledge gap exists concerning the evolution of fetal diurnal rhythms into infant sleep-wake cycles. ObjectiveTo investigate the development of fetal diurnal rhythms and their evolution into postnatal infant sleep, as well as the role of maternal factors and melatonin in shaping early circadian entrainment. MethodsIn this cohort study, conducted in 2022 and 2023, we collected over 20 000 hours of wearable acceleration and temperature data from 32 fetuses and their mothers during continuous 5-day monitoring in the third trimester of pregnancy. The cohort was subsequently followed longitudinally from the prenatal period through 6 months postpartum, with infant sleep outcomes assessed at three key time points (first postnatal weeks, 3 months, and 6 months) using sleep diaries and questionnaires. The first postnatal assessment additionally included breast milk and infant stool sample collection. ResultsMulti-level modelling revealed early diurnal rhythms in fetuses that align with maternal activity and circadian rhythms. Random Forest analyses identified fetal day/night sleep duration ratio - a simplified proxy for fetal circadian entrainment - as the strongest predictor of postnatal infant sleep, with fetuses preferring nighttime sleep maintaining this preference postnatally. Maternal sleep regularity (i.e., consistent sleep patterns characterized by low day-to-day variability in sleep timing) during pregnancy also predicted infant sleep, associating with a stronger preference for nighttime sleep in infants. Conclusions and relevanceThese findings highlight the potential influence of intrauterine and maternal factors on the evolution of circadian entrainment. Our study contributes to a broader understanding of the earliest emergence of circadian rhythms, supporting future research on their long-term health impacts. Maternal sleep regularity stands out as the earliest modifiable target for interventions, offering an actionable pathway to promote infant circadian entrainment, with potential long-term benefits for family dynamics and well-being.

developmental biology↗

bioRxiv2024

The Infraslow Fluctuation of Sigma Power During Sleep: Links to Markers of Arousal and Memory Reactivation Across Development

Sleep is both a state of disconnection from the environment and a critical period for restoration. But how does sleep balance responsiveness with the protection of key functions? The infraslow fluctuation of sigma power (ISFS)--the clustering of sleep spindles over 10-100 seconds--is thought to regulate this trade-off in rodents. However, the organization of arousal and memory reactivation markers within the human ISFS and its conservation in younger ages remain unclear. This study characterizes the ISFS from childhood to young adulthood (N = 154; ages 8-26), examining its relationship with functional markers. Results indicate that the ISFS is present across all ages, with frequency, variability, and strength increasing from early to late adolescence. Notably, markers of arousal and memory reactivation are organized within the spindle-rich ISFS peak. The consistent presence and organization of the ISFS suggest it is intrinsic to sleep, with adolescence marking a dynamic window. These insights may guide interventions to promote healthier sleep across development.

neuroscience↗

bioRxiv2024

Wake EEG oscillation dynamics reflect both sleep need and brain maturation across childhood and adolescence

1An objective measure of brain maturation is highly insightful for monitoring both typical and atypical development. Slow wave activity, recorded in the sleep electroencephalogram (EEG), reliably indexes age-related changes in sleep pressure as well as deficits related to developmental disorders such as attention-deficit hyperactivity disorder (ADHD). We aimed to determine whether wake EEG measured before and after sleep could index the same developmental changes in sleep pressure, using data collected from 163 participants 3-25 years old. We analyzed ageand sleep-dependent changes in two measures of oscillatory activity, amplitudes and density, as well as two measures of aperiodic activity, offsets and exponents. We then compared these wake measures to sleep slow wave amplitudes and slopes. Finally, we compared wake EEG in children with ADHD (N=58) to neurotypical controls. Of the four wake measures, only oscillation amplitudes consistently exhibited the same changes as sleep slow waves. Wake amplitudes decreased with age, decreased after sleep, and this overnight decrease decreased with age. Furthermore, wake amplitudes were significantly related to both sleep slow wave amplitudes and slopes. Wake oscillation densities decreased overnight in children but increased overnight in adolescents and adults. Aperiodic offsets decreased linearly with age, decreased after sleep, and were significantly related to sleep slow wave amplitudes. Aperiodic exponents also decreased with age, but increased after sleep. No wake measure showed significant effects of ADHD. Overall, our results indicate that wake oscillation amplitudes, and to some extent aperiodic offsets, behave like sleep slow waves across sleep and development. At the same time, overnight changes in oscillation densities independently reflect some yet-unknown shift in neural activity around puberty.

neuroscience↗

bioRxiv2021

An Infant Sleep Electroencephalographic Marker of Thalamocortical Connectivity Predicts Behavioral Outcome in Late Infancy

Infancy represents a critical period during which thalamocortical brain connections develop and mature. Deviations in the maturation of thalamocortical connectivity are linked to neurodevelopmental disorders. There is a lack of early biomarkers to detect and localize neuromaturational deviations, which can be overcome with mapping through high-density electroencephalography (hdEEG) assessed in sleep. Specifically, slow waves and spindles in non-rapid eye movement (NREM) sleep are generated by the thalamocortical system, and their characteristics, slow wave slope and spindle density, are closely related to neuroplasticity and learning. Recent studies further suggest that information processing during sleep underlying sleep-dependent learning is promoted by the temporal coupling of slow waves and spindles, yet slow wave-spindle coupling remains unexplored in infancy. Thus, we evaluated three potential biomarkers: 1) slow wave slope, 2) spindle density, and 3) the temporal coupling of slow waves with spindles. We use hdEEG to first examine the occurrence and spatial distribution of these three EEG features in healthy infants and second to evaluate a predictive relationship with later behavioral outcomes. We report four key findings: First, infants EEG features appear locally: slow wave slope is maximal in occipital and frontal areas, whereas spindle density is most pronounced frontocentrally. Second, slow waves and spindles are temporally coupled in infancy, with maximal coupling strength in the occipital areas of the brain. Third, slow wave slope, spindle density, and slow wave-spindle coupling are not associated with concurrent behavioral status (6 months). Fourth, spindle density in central and frontocentral regions at age 6 months predicts later behavioral outcomes at 12 and 24 months. Neither slow wave slope nor slow wave-spindle coupling predict behavioral development. Our results propose spindle density as an early EEG biomarker for identifying thalamocortical maturation, which can potentially be used for early diagnosis of neurodevelopmental disorders in infants. These findings are complemented by our companion paper that demonstrates the linkage of spindle density to infant nighttime movement, framing the possible role of spindles in sensorimotor microcircuitry development. Together, our studies suggest that early sleep habits, thalamocortical maturation, and behavioral outcome are closely interwoven. A crucial next step will be to evaluate whether early therapeutic interventions may be effective to reverse deviations in identified individuals at risk. HighlightsO_LISlow waves and spindles occur in a temporally coupled manner in infancy C_LIO_LISlow wave slope, spindle density, and slow wave-spindle coupling are not related to concurrent behavioral development C_LIO_LISpindle density at 6 months predicts behavioral status at 12 and 24 months C_LIO_LISlow wave slope and slow wave-spindle coupling are not predictive of behavioral development C_LI

neuroscience↗

bioRxiv2021

Bedtime to the brain: How infants sleep habits intertwine with sleep neurophysiology

Adequate sleep is critical for development and facilitates the maturation of the neurophysiological circuitries at the basis of cognitive and behavioral function. Observational research has associated sleep problems in early life with worse later cognitive, psychosocial, and somatic health outcomes. Yet, the extent to which day-to-day sleep habits in early life relate to neurophysiology - acutely and long-term - remains to be explored. Here, we report that sleep habits in 32 healthy 6-month-olds assessed with actimetry are linked to fundamental aspects of their neurophysiology measured with high-density electroencephalography (hdEEG). Our study reveals four key findings: First, daytime sleep habits are linked to EEG slow wave activity (SWA). Second, habits of nighttime movement and awakenings from sleep are connected with spindle density. Third, habitual sleep timing is linked to neurophysiological connectivity quantified as Delta-coherence. And lastly, Delta-coherence at age 6 months predicts nighttime sleep duration at age 12 months. These novel findings widen our understanding that infants sleep habits are closely intertwined with three particular levels of neurophysiology: sleep pressure (determined by SWA), the maturation of the thalamocortical system (spindles), and the maturation of cortical connectivity (coherence). Our companion paper complements this insight in the perspective of later developmental outcomes: early thalamocortical connectivity (spindle density) at age 6 months predicts later behavioural status at 12 and 24 months. The crucial next step is to extend this concept to clinical groups to objectively characterize infants sleep habits "at risk" that foster later neurodevelopmental problems. HighlightsO_LIInfants habitual sleep behavior (actimetry) is linked with their sleep neurophysiology (EEG) C_LIO_LIHabits of daytime sleeping (naps) are related to slow wave activity C_LIO_LIInfants movements and awakenings at nighttime are linked to their sleep spindles C_LIO_LISleep timing (infants bedtimes) is associated with cortical connectivity in the EEG C_LI

neuroscience↗

bioRxiv2020

Which are the central aspects of infant sleep? Thedynamic of sleep composites across infancy

Sleep is ubiquitous during infancy and important for the well-being of both infant and parent. Therefore, there is large interest to characterize infant sleep with reliable tools, for example by means of combining actigraphy with 24-h-diaries. However, it is critical to select the right variables to characterize sleep. With a principal component analysis, we identified 5 underlying sleep composites from 48 commonly used sleep variables: Sleep Night, Sleep Day, Sleep Activity, Sleep Timing and Sleep Variability. These composites accurately reflect the known changes of sleep throughout infancy as Sleep Day (representing naps), Sleep Activity (representing sleep efficiency and consolidation) and Sleep Variability (representing day-to-day stability) decrease across infancy, while Sleep Night (representing nighttime sleep) slightly increases and Sleep Timing becomes earlier with increasing age. Additionally, we uncover interesting dynamics between the sleep composites and demonstrate that infant sleep is not only highly variable between infants but also considerably dynamic within infants across time. Interestingly, Sleep Day is associated with behavioral development and therefore a potential marker for maturation. We recommend the use of sleep composites or of those specific single variables, which are solid representatives of the sleep composites for more reliable research.

neuroscience↗

bioRxiv2018

Actimetry in infant sleep research: an approach to facilitate comparability

Study ObjectivesOnly standardized objective assessments reliably capture the large variability of sleep behavior in infancy, which is the most pronounced during the human lifespan. This is important for clinical as well as basic research. Actimetry is a cost-efficient method to objectively track infant sleep/wake behavior by assessing limb movements. Nevertheless, the standardization of actimetry-based sleep/wake measures is limited by two factors: the use of different computational approaches and the bias towards measuring only nighttime sleep - neglecting [~]20 % of sleep infants obtain during daytime.\n\nMethodsWe used actimetry in 50 infants for 10 continuous days at ages 3, 6 and 12 mo in a longitudinal approach. We analyzed the infants sleep/wake behaviors applying with two commonly used algorithms: Sadeh and Oakley/Respironics. We compared minute-by-minute agreement and Kappa between the two algorithms, as well as the algorithms with sleep/wake measures from a comprehensive 24-hour, parent-reported diary.\n\nResultsAgreement between uncorrected algorithms was moderate (77 - 84%). By introducing a 6-step adjustment, we increased agreement between algorithms (96 - 97%) and with the diary. This decreased the difference between the two algorithms in e.g. Total Sleep Duration from 4.5 h to 0.2 h.\n\nConclusionsThis computational pipeline enhances comparability between infant actimetry studies and the inclusion of parent-reported diaries allows the integration of daytime sleep. Objectively assessed infant sleep that is comparable across different studies supports the establishment of normative developmental trajectories and clinical cutoffs.

neuroscience↗