Developmental Science

Visual orthographic knowledge plays a critical role in early literacy development and may provide a shared foundation for reading and spelling, yet the nature of its underlying representations remains debated. Behavioral measures offer indirect evidence and may be influenced by other metalinguistic processes. It remains unclear whether beginning readers encode larger orthographic structures, such as onset-rime units, beyond individual letters and smaller letter combinations but below the whole-word level. It is also unknown whether neural sensitivity to these structures helps explain the relationship between spelling and reading. To address these questions, we used a fast periodic visual stimulation (FPVS) paradigm in first- and second-grade children to contrast pseudowords constructed with the typical ordering of onset followed by rime elements (i.e., onset-rime) against matched strings in which the same elements appeared in the reverse order (i.e., rime-onset). Neural sensitivity to onset-rime orthographic structure was associated with both spelling ability and word-reading efficiency and, critically, statistically mediated the relationship between these two literacy skills. These relationships remained significant after controlling for age and removing influential observations, and sensitivity to onset-rime orthographic structure explained additional variance in word-reading efficiency beyond spelling ability and age. Together, these findings provide neurophysiological evidence for onset-rime structure as an important sublexical orthographic unit in beginning readers, highlighting its potential role in linking spelling with efficient word recognition during early reading development.

Selective attention, the ability to focus on relevant information while ignoring task-irrelevant information, is crucial for learning. Selective attention has largely been studied in motionless individuals. However, body movements are intrinsic to cognition and particularly frequent in children. To test whether movements explain successful attention control throughout childhood, we tracked head rotations while younger children (6-8 years, n = 25), older children (9-10 years, n = 20) and adults (18-30 years; n = 21) identified a spatial target sound under distraction. Distractor reports decreased with age, confirming a developmental increase in attention control. Importantly, a dissociation of two distinct types of movement emerged: Task-dependent head rotation to lateral targets was similar across age groups. Contrary, task-independent movements before and early during a trial decreased with age and predicted attention accuracy. Thus, movements unrelated to the attention goal do not reflect noise but signify attentional control across development.

The development of speech in human children is a protracted process that depends on social experience. From early life, young children produce vocalizations in the presence of others, which affords unique opportunities for feedback about how to communicate successfully. However, for feedback to happen, young childrens speech needs to effect change in the brains of their caregivers. Using dual-brain functional near-infrared spectroscopy (fNIRS) to measure real-time communication between caregivers and their 2- to 3-year-old children (n = 56), we found that children's vocalizations selectively modulated caregivers' brain activity. Parents' brains showed a rapid response to children's production of speech that was communicatively advanced (multiword utterances) vs. less advanced (babble). The findings imply that if part of learning to talk is figuring out how to get your communication partner to listen, then early conversations likely present continuous opportunities for feedback that guide children toward advances in spoken language.

Developmental dyslexia is associated with impaired cortical tracking of continuous speech and difficulties in perceiving within-word prosodic structure in children and adults. For adults and continuous speech, both low-frequency delta- and theta-band impairments and high-frequency gamma- and beta-band differences are found. To date, perceptual difficulties with intra-word prosody have not been studied in direct relation to neural speech encoding. Here neurotypical adults and adults with dyslexia listened to multisyllabic words. EEG was recorded, and cortical encoding was quantified using temporal response function (TRF) modelling. Four speech representations were explored: lexical stress pattern (intra-word prosodic prominence), the low-frequency speech envelope, word onsets and syllable onsets. Adults with dyslexia showed significantly reduced encoding of intra-word prosodic prominence (delta band) and of the speech envelope (delta and theta bands). In contrast, encoding of word and syllable onsets was preserved. Pinpointing delta-band cortical tracking as central to encoding intra-word prosodic prominence opens new avenues for research.

Background: Infants with extremely low birth weight (ELBW) are at high risk for neurodevelopmental impairment, but the relationship between cerebellar structure and later developmental outcome remains incompletely defined. Methods: In this retrospective single-center study, we examined total cerebellar volume on clinically acquired brain magnetic resonance imaging (MRI) in ELBW infants while accounting for postmenstrual age (PMA) at imaging. Results: Of 65 infants screened, 42 were included. Mean gestational age at birth was 25.54 {+/-} 1.68 weeks, mean birth weight was 733.2 {+/-} 118.7 g, and mean PMA at MRI was 43.02 {+/-} 6.53 weeks (range, 31.57--68.00). Mean cerebellar volume was 22.17 {+/-} 9.63 cm. Independently adjudicated developmental outcomes comprised normal development in 16 infants, isolated or specific impairment in 12, and moderate/severe impairment in 14. Unadjusted cerebellar volumes did not differ across developmental groups (P = 0.490) or qualitative MRI categories (P = 0.875). However, the PMA-by-developmental-category interaction was significant (P = 0.002), with estimated cross-sectional slopes of 1.72, 1.56, and 0.39 cm per week, respectively. The interaction remained significant within 36--46 weeks PMA (n = 29; P = 0.011) and after adjustment for small-for-gestational-age (SGA) status. Sensitivity analyses indicated uncertainty in the stability of the interaction. Conclusions: These findings suggest that age-informed cerebellar volumetric patterns may provide developmental information not evident from average volumes alone and support prospective validation with standardized imaging and developmental assessments. As a result, cerebellar volumes obtained early in life may hold prognostic information for ELBW infants.

Exploration is fundamental to how children learn about the world. To explore a new environment comprehensively, a child must navigate without getting lost while simultaneously attending to salient information along the way. Both abilities improve across childhood, yet most studies examine them in isolation, often in constrained spaces with limited sensory complexity. Here, we asked 7- to 14-year-old children (N=42) and young adults (18-22; N=42) to freely explore a large furniture store in immersive virtual reality, which contained many objects and attention-capturing multisensory events. Surprisingly, despite traveling comparable distances, children explored less - they covered less spatial area and examined fewer unique objects than adults. Fine-grained analyses of their behaviors showed that the reduction in exploration was due to children spending more time backtracking and children taking longer to adapt to salient multisensory objects, which were uncorrelated across individuals after controlling for age and independently predicted exploration. However, only backtracking duration predicted success in a subsequent search task, demonstrating a link between navigational success during exploration and the quality of learned spatial representations for later use. Together, the results demonstrate that children explore less comprehensively than adults in large-scale spaces because they are susceptible to getting lost and perseverating on salient events nested within a large environment, but that these behaviors change with age. This suggests that while children are widely considered to be curious explorers within local environments, their ability to do so within larger environments is shaped by the maturation of cognitive systems that integrate experiences over complex contexts.

Sensorimotor synchronization, the ability to align motor behaviour with the temporal structure of external stimuli, is thought to emerge gradually during development, but its origins remain unclear. Here, we investigated whether newborns can adapt their sucking behaviour and synchronise it to the temporal structure of auditory stimuli within the first days of life. Forty-one healthy full-term newborns (24-72 hours old) were exposed to two three-minute auditory streams differing in temporal structure: a highly structured stream with a stable temporal pattern and a highly variant stream with greater temporal variability, while their non-nutritive sucking (NNS) was continuously recorded. We assessed changes in NNS frequency and pressure and quantified NNS-sound coupling using magnitude-squared coherence at frequencies distinctive to each auditory stream. Structured stimulation promoted a more organised NNS, with more suck bursts than the variant stream, and increased sucking vigour, with a transiently higher suck peak rate during the first minute relative to the variant stream and greater suck pressure relative to silence. Coherence analyses revealed that coherence was selectively higher at the frequencies distinctive to each auditory stream, both for the structured and the highly variant stimulus. These findings show that, within hours of birth, NNS behaviour can selectively align with stimulus-specific temporal regularities, even when these are weakly predictable and lack a dominant periodicity. This early capacity to extract temporal structure and coordinate motor behaviour may provide a foundation for the subsequent development of sensorimotor synchronisation.

Musical aesthetic experience can reveal students' cognitive, aesthetic, and emotional responses to music. However, how professional vocal training alters brain functions in female college students with varying levels of musicianship to promote these is unknown. Here we applied fMRI, psychological measures and Goldsmiths musical sophistication index (Gold-MSI) assessments to study 27 non-music major female college students consisting of instrument group (normal pitch accuracy with instrumental training), general group (normal pitch accuracy without instrumental training) and poor-pitch group (poor pitch accuracy and without instrumental training). After 1 year of one-on-one instructional practice, we found that professional vocal training enhanced information processing related to musical cognition and pleasure during musical aesthetic experiences across all three groups, involving improvements in motor control of vocalization, auditory feedback processing, musical memory and attention together with musical pleasure. Specifically, instrument group showed activation of reward circuits, general group exhibited activation of laryngeal motor control circuits, and poor-pitch group displayed activation of sensory/sensorimotor/motor control circuits. Both pre- and post-training, the instrument group exhibited higher connectivity than the other two groups in the left amygdala-dorsal anterior cingulate cortex (dACC) and the right posterior superior temporal gyrus (pSTG)-left insula pathway. After professional vocal training, the general group showed higher connectivity in the left amygdala-dACC, whereas the poor-pitch group demonstrated increased connectivity in the right pSTG-left insula and dACC-nucleus accumbens pathways. Surprisingly, professional vocal training activated the bed nucleus of the stria terminalis (BNST), a subcortical emotion center, and connectivity with the medial prefrontal cortex associated with musical information processing. Thus, vocal training can significantly improve musical cognition and aesthetic pleasure, and facilitates neural modulation in the brain's emotional centers.

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.

Categorical rhythmic patterns are fundamental features found in language and music across cultures. In humans, these rhythmic patterns occur in both vocal production and perceptual preference, highlighting a link between rhythmic production and preference. Categorical rhythmic patterns have recently been identified in animal vocalisations too, but whether rhythm production is linked with rhythmic preferences in non-human animals remains unclear. Within this context, zebra finches (Taeniopygia castanotis) are of particular interest, as both sexes develop a song preference, and their song has been suggested to exhibit an isochronous temporal structure. Here, we tested for the first time whether zebra finches prefer songs containing discrete rhythmic patterns, using operant preference tests with either two or four rhythmic patterns. Our results show that no categorical rhythmic pattern was consistently preferred across the population, although responses varied among individuals. These findings indicate that categorical rhythmic patterns are unlikely to be a primary driver of song preference in zebra finches. Together with previous work in other vocal-learning birds, our results suggest that preferences for categorical rhythmic patterns may not be universal and could instead reflect species-specific features of vocal displays rather than the rhythmic categories characteristic of human music.

Reading behaviour is sensitive to contextual demands. For example, when reading to study or answer questions, readers strategically allocate more attention to goal-relevant sections, read slower, and regress more frequently to extract specific information based on task demands. This suggests that readers flexibly adapt their strategies according to goals and situational constraints. However, the neurocognitive mechanisms supporting this flexibility remain unclear. To test this, we combined eye-tracking with EEG during naturalistic reading and examined how short-term reading goals modulated the neural tracking of hierarchical linguistic features at the orthographic (orthographic neighbourhood size), lexical (word frequency), and contextual-semantic (Surprisal) levels. Forty native English speakers read narratives in three goal conditions: Baseline (no goal), Proofreading (detect spelling errors), and Comprehension (attend to content). Fixation-aligned word-level EEG activity was modelled using multivariate temporal response function to estimate the strength of feature-specific neural tracking. Orthographic tracking was significantly enhanced during Proofreading relative to Baseline, and predicted better Proofreading accuracy. Conversely, stronger frequency tracking predicted better Comprehension accuracy. Contextual-semantic tracking was not modulated by task goal. These findings suggest that reading goals selectively bias neural processing towards linguistic features (sublexical vs. lexical) that support successful task performance, providing evidence for short-term functional plasticity in linguistic processing and supporting a flexible predictive processing account of goal-directed reading.

Humans routinely encounter speech in languages they have never heard, yet how the brain responds to such input and whether bilingual experience shapes this response remains unknown. Here, we used electroencephalography (EEG) and temporal response function (TRF) modeling to examine cortical tracking of the speech envelope in 24 English-monolingual and 24 English-Mandarin bilingual adults. Participants listened to naturally produced continuous speech in three languages: English (familiar to all), Mandarin (familiar to bilinguals only), and Vietnamese (unfamiliar to all). We report two main findings. First, both monolinguals and bilinguals showed enhanced cortical tracking for unfamiliar relative to familiar languages, evidenced by higher EEG prediction accuracy (PA). Monolinguals showed enhanced tracking for both Mandarin and Vietnamese, whereas bilinguals showed enhancement only for Vietnamese, consistent with Mandarin being a familiar language for this group. This finding suggests that enhanced cortical encoding of unfamiliar speech is a general property of the listening brain, not a signature of listening to a non-native language or reduced language proficiency. Second, bilinguals strikingly showed stronger cortical tracking than monolinguals overall, in both PA and TRF peak weights, with the TRF peak weight advantage present across all three languages, suggesting a difference in how bilingual experience shapes the neural encoding of speech. These findings have implications for understanding how the brain navigates the linguistic diversity of everyday life in an increasingly global, multilingual world.

Understanding how native speakers and second language (L2) learners process language differently is fundamental to theories of language acquisition, comprehension, and use. A central debate in this literature concerns the inconsistent findings in emotional prosody processing between native speakers and L2 learners, partly attributable to stimulus lexicality: some studies use real words, whereas others use pseudowords. To resolve this discrepancy, we measured fMRI responses in 15 native speakers and 15 L2 learners while they listened to Mandarin real-word and pseudoword stimuli. Both groups engaged in overlapping auditory, cognitive, and affective regions, including the auditory cortex, inferior frontal cortex, superior temporal cortex, and the temporoparietal junction. However, the two groups showed distinct responses depending on lexicality: native speakers showed stronger recruitment of temporal regions for pseudowords, whereas L2 learners showed greater frontoparietal activation for real words. These patterns were consistent across positive and negative prosody conditions. Furthermore, among L2 learners, higher proficiency was associated with greater frontal activation for real words, but not pseudowords. Together, these findings demonstrate that the differences between native speakers and L2 learners depend critically on stimulus lexicality, highlighting the role of lexicality in bilingual emotion processing.

Although human perception appears continuous, converging evidence suggests that sensory input is integrated over discrete temporal windows. The duration of these Temporal Integration Windows (TIWs) determines the temporal resolution of perception, but how this fundamental property develops across infancy and childhood remains unknown. Here, we estimate TIW duration from 5 months of age to adulthood using a novel, instruction-free eye-tracking paradigm that isolates pre-attentive visual integration. Across four experiments with the same paradigm (N = 308 participants), we measured spontaneous detection of a visual target that emerges only when two alternating displays are integrated within a single perceptual window. We observed a striking developmental shortening of the TIW. In adults and 5-year-olds, integration succeeded at short interstimulus intervals (ISIs; 16-32 ms) but failed at longer intervals (83-116 ms), yielding an estimated TIW of [~]57 ms. At 3 years, the TIW extended to [~]100 ms. In infancy, integration remained robust at substantially longer ISIs, with estimates of [~]250 ms at 18 and 8 months, and [~]400 ms at 5 months. The steepest reduction occurred within the first year of life. These findings reveal an approximately sevenfold acceleration in the temporal resolution of visual perception from early infancy to adulthood. Progressive shortening of TIWs suggests that infants and adults integrate sensory information over fundamentally different temporal scales, with implications for perceptual organization, learning, and neurodevelopmental trajectories.

Working memory (WM), a core executive function that supports learning and reasoning, undergoes rapid development during early childhood years. Neural activation patterns underlying WM have been extensively studied in both adults and children, revealing increasing involvement of the frontoparietal network (FPN) with age and coordinated interactions with the default mode network (DMN). However, relatively little is known about how these network interactions develop in children, particularly within the visuospatial domain. The present study investigated the influence of age and task performance on effective connectivity within the FPN and its interactions with DMN hubs during a visuospatial WM task in early childhood. Functional MRI data were collected during a visual n-back task with two WM load levels (0-back and 2-back) in 120 typically developing children aged 5-8 years. Dynamic Causal Modeling (DCM) with parametric empirical Bayes was used to estimate effective connectivity among eight regions of interest spanning the FPN and DMN. Behaviorally, age-related gains were steepest under high-load for accuracy, and under low-load for reaction time, suggesting WM capacity is a demand-sensitive marker of development at this age. At the network level, high-load robustly engaged the FPN, whereas low-load was associated with relatively greater engagement of DMN and episodic memory-related regions. Baseline effective connectivity was dominated by parietal-to-frontal drive and strong self-inhibition in the anterior cingulate cortex. Age-related effects on this architecture were sparse, involving asymmetric interhemispheric frontal coupling and reduced parieto-cingulate coupling, whereas accuracy-related effects were larger in magnitude, particularly at self-connections. More accurate children showed greater excitability in frontal and parietal FPN nodes alongside increased self-inhibition in the precuneus, a DMN hub, consistent with a neural efficiency account in which better performance reflects more selective, rather than more global, network engagement. Task load further shaped connectivity in distinct ways: low-load elicited widespread inter-regional modulation, whereas high-load predominantly modulated self-connections, with age and accuracy effects on this modulation dissociating by load. These findings suggest that, in primary school children, current task performance was associated with more pronounced differences in frontoparietal effective connectivity than was age, and that WM-related network engagement becomes increasingly selective and load-dependent across this developmental window.

Inhibitory control deficits have long been proposed as a central neurocognitive mechanism underlying childhood Attention Deficit/Hyperactivity Disorder (ADHD). However, neuroimaging findings remain heterogeneous, partly due to methodological variability across developmental samples and experimental paradigms. The present study aimed to characterize the neural architecture of motor response inhibition in typically developing (TD) children and identify reproducible functional abnormalities associated with pediatric ADHD using stringent, developmentally specific inclusion criteria. We conducted two coordinate-based meta-analyses using Activation Likelihood Estimation (ALE). Following a systematic literature search (up to August 2026), we identified 23 task-based fMRI studies reporting inhibitory-control-related activation in TD children (237 foci) and 17 studies comparing children with ADHD and TD peers (114 foci) during the Stop-Signal Task or Go/No-Go Task. All participants were younger than 18 years of age. Statistical significance was determined using cluster-level family-wise error (FWE) correction. In TD children, ALE revealed a robust inhibitory-control network encompassing the bilateral anterior insula (AI), inferior frontal gyrus (IFG), and the midline pre-supplementary motor area (preSMA) and anterior cingulate cortex (ACC). This spatial organization closely resembled the canonical inhibitory-control network consistently observed in adults, suggesting that the core neural architecture supporting motor inhibition is already detectably organized during development. In the between-group analysis, children with ADHD exhibited significant hypoactivation primarily within the preSMA. Notably, this region demonstrated striking spatial overlap with the preSMA cluster reliably recruited in TD children during motor inhibition. These findings provide convergent support for inhibitory-control models of ADHD and identify altered preSMA recruitment as one of the most consistent functional abnormalities associated with pediatric ADHD. While the neural infrastructure supporting inhibitory control is broadly established during childhood, children with ADHD exhibit reduced recruitment of a key cortical node within this network during motor inhibition demands.

Family environment is a robust predictor of adolescent internalizing symptoms, yet its strength varies across adolescents. We tested whether this variation is partly captured by how similar an adolescent's cortical structure is to their parent's and whether different forms of this similarity matter in different cortical systems. In 115 parent-child dyads from two cohorts, structural MRI quantified similarity across 400 cortical parcels in two forms: phenotypic similarity in regional morphometry and architectural similarity in interregional morphometric organization. Parent-child similarity was not directly associated with symptoms, whereas its interactions with family environment were jointly significant (chi-square(4) = 14.92, P = 0.005). Phenotypic similarity in the sensory-limbic system and architectural similarity in the association system each moderated the association between family environment and symptoms (both beta = 0.22). In both cases, the association was strongest among less similar dyads. The phenotypic interaction was distributed across sensory-limbic networks and was not reproduced by similarity to unrelated adults or by the child's cortical atypicality. The architectural interaction was concentrated in the dorsal attention and default mode networks and was distinguishable from unrelated-adult similarity but not from child atypicality. Together, these findings raise the possibility that markers of environmental sensitivity need not reside in the child alone. Parent-child cortical similarity may index a dyadic component of this sensitivity, one not adequately represented by a single similarity score but distributed across forms of similarity and cortical systems.

Altered sensitivity to sounds despite normal peripheral hearing is common in neurodevelopmental disorders but the underlying mechanisms remain poorly understood. Here we investigate tonotopic organization in 86 children (6-11 years) with autism spectrum and related neurodevelopmental disorders as well as typically developing (TD) peers, using a child-friendly, passive listening, functional magnetic resonance imaging design. In TD children, tonotopic maps in primary auditory cortex resembled the typical high-low-high frequency gradients previously reported in adults, while children with autism showed an overrepresentation of high frequencies consistent with what has been observed in animal models of autism. Higher frequency tuning further correlated with greater caregiver-reported sound but not touch sensitivities. Importantly, tonotopy is a core organizational feature of auditory cortex that develops early in life and remains relatively stable after the critical period of heightened plasticity ends. Thus, these results suggest that atypical auditory processing in autism may result from early disruption to tonotopic map formation. Longitudinal neuroimaging studies are needed to understand the genetic and environmental causes of altered auditory cortex topology and its long-term consequences for higher-level auditory, language, and social communication development.

Disorders of consciousness (DoC) are characterised by marked reductions in cerebral glucose metabolism, but the specific cellular and neurochemical processes driving this impairment remain unclear. To elucidate these mechanisms, a multimodal imaging approach combining [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance spectroscopy (MRS) was applied to the posterior medial cortex (PMC) in 15 DoC patients and 14 healthy controls. Regional FDG metabolic index (FDG-MI) values and MRS concentration estimates of glutamate plus glutamine (Glx), {gamma}-aminobutyric acid (GABA+), total N-acetylaspartate (tNAA), total creatine (tCr), and total choline (tCho) were compared between groups and evaluated against Coma Recovery Scale-Revised (CRS-R) scores at baseline and follow-up (mean 127 days). Patients demonstrated reductions within the PMC in Glx, tCr, and tNAA concentrations, as well as a reduced Glx/GABA+ ratio. Local FDG-MI was substantially reduced in patients and correlated positively with tNAA and tCr. Furthermore, baseline tCho concentrations positively predicted long-term clinical recovery, as indexed by changes in CRS-R scores at follow-up. These findings suggest that macroscopic glucose hypometabolism in DoC may be linked to disrupted intracellular mitochondrial energy production pathways and a shift towards relative synaptic inhibition in the PMC. Moreover, the association between choline levels and behavioural recovery may point to the relevance of retained structural synthesis capacity for functional outcomes.

Compositional syntax - the ability to combine meaningful units into structured sequences whose overall meaning depends on both the meanings of the parts and their combination - is a hallmark of human language. Recent work suggests that chimpanzees may exhibit similar capacities, raising the possibility that compositionality predates the emergence of language in humans. However, a key challenge has been to exclude simpler explanations in which call combinations are processed as independent utterances rather than integrated structures. Here, we address this issue using a source-manipulation paradigm in playback experiments with captive chimpanzees (n = 6) at the Sigean African Reserve, France. We presented sequences combining alarm and recruitment calls either from a single source (one loudspeaker) or from two spatially distinct sources (two loudspeakers). If sequences are interpreted as independent calls, responses should not differ between conditions. Instead, chimpanzees responded significantly faster when sequences originated from a single source. Bayesian survival analyses confirmed this effect. These results support a non-trivial form of compositionality, whereby the meaning of call combinations depends on their integration into a unified sequence produced by a single individual. Our findings provide experimental evidence that key features of linguistic compositionality may have evolutionary roots in the primate lineage.