Explore the vast range of titles available.

Neocortical maturation is a dynamic process that proceeds in a hierarchical manner; however, the spatiotemporal organization of cortical microstructure with diffusion MRI has yet to be fully defined. This study characterized cortical microstructural maturation using diffusion MRI (fwe‐diffusion tensor imaging [DTI] and neurite orientation dispersion and density imaging [NODDI] multicompartment modeling) in a cohort of 637 children and adolescents between 8 and 21 years of age. We found spatially heterogeneous developmental patterns broadly demarcated into functional domains where NODDI metrics increased, and fwe‐DTI metrics decreased with age. By applying nonlinear growth models in a vertex‐wise analysis, we observed a general posterior‐to‐anterior pattern of maturation, where the fwe‐DTI measures mean diffusivity and radial diffusivity reached peak maturation earlier than the NODDI metrics neurite density index. Using non‐negative matrix factorization, we found occipito‐parietal cortical regions that correspond to lower order sensory domains mature earlier than fronto‐temporal higher order association domains. Our findings corroborate previous histological and neuroimaging studies that show spatially varying patterns of cortical maturation that may reflect unique developmental processes of cytoarchitectonically determined regional patterns of change. We quantified regional patterns of cortical maturation across childhood and adolescence using multiple advanced diffusion MRI models that probe different aspects of the microstructural organization of the developing cortex. We found heterogeneous patterns of cortical maturation that proceed in a hierarchical manner, which we interpret as varying degrees of myelination, dendritic arborization, and axonal pruning.

While the main neural networks are in place at term birth, intense changes in cortical microstructure occur during early infancy with the development of dendritic arborization, synaptogenesis and fiber myelination. These maturational processes are thought to relate to behavioral acquisitions and the development of cognitive abilities. Nevertheless, in vivo investigations of such relationships are still lacking in healthy infants. To bridge this gap, we aimed to study the cortical maturation using non-invasive Magnetic Resonance Imaging, over a largely unexplored period (1–5 post-natal months). In a first univariate step, we focused on different quantitative parameters: longitudinal relaxation time (T1), transverse relaxation time (T2), and axial diffusivity from diffusion tensor imaging (λ//) These individual maps, acquired with echo-planar imaging to limit the acquisition time, showed spatial distortions that were first corrected to reliably match the thin cortical ribbon identified on high-resolution T2-weighted images. Averaged maps were also computed over the infants group to summarize the parameter characteristics during early infancy. In a second step, we considered a multi-parametric approach that leverages parameters complementarity, avoids reliance on pre-defined regions of interest, and does not require spatial constraints. Our clustering strategy allowed us to group cortical voxels over all infants in 5 clusters with distinct microstructural T1 and λ// properties The cluster maps over individual cortical surfaces and over the group were in sound agreement with benchmark post mortem studies of sub-cortical white matter myelination, showing a progressive maturation of 1) primary sensori-motor areas, 2) adjacent unimodal associative cortices, and 3) higher-order associative regions. This study thus opens a consistent approach to study cortical maturation in vivo. [Display omitted] •The cortical maturation was studied in infants between 1 and 5 months of age.•Diffusion and relaxometry MRI were analyzed in univariate and multivariate manner.•Clustering analyses provided reliable results both at the subject and group levels.•Distinct maturation profiles were shown across regions of the infant cortex.

Sensory processing during development is important for the emerging cognitive skills underlying goal-directed behavior. Yet, it is not known how auditory processing in children is related to their cognitive functions. Here, we utilized combined magneto- and electroencephalographic (M/EEG) measurements in school-aged children (6-14y) to show that child auditory cortical activity at ∼250 ms after auditory stimulation predicts the performance in inhibition tasks. While unaffected by task demands, the amplitude of the left-hemisphere activation pattern was significantly correlated with the variability of behavioral response time. Since this activation pattern is typically not present in adults, our results suggest divergent brain mechanisms in adults and children for consistent performance in auditory-based cognitive tasks. This difference can be explained as a shift in cortical resources for cognitive control from sensorimotor associations in the auditory cortex of children to top–down regulated control processes involving (pre)frontal and cingulate areas in adults.

Introduction: The present study aimed to compare cortical auditory maturation, as reflected by P1 latency of cortical auditory evoked potentials (CAEPs), in children with congenital severe-to-profound sensorineural hearing loss rehabilitated with unilateral cochlear implants (CIs) or bilateral conventional hearing aids (HAs). Materials and Methods: Eighty-five children with congenital severe-to-profound sensorineural hearing loss were included in this retrospective comparative study. Participants were divided into two groups: unilateral CI users (n = 42) and bilateral HA users (n = 43). All children were fitted with their devices before 48 months of age and achieved aided free-field thresholds between 30 and 50 dB HL. CAEPs were recorded using the Fonix® HEARLab System with speech stimuli (/m/, /g/, /t/) presented at 55 dB SPL. P1 latency values were measured and compared between groups using independent samples t-tests. Correlation analyses were performed to assess the relationship between duration of device use and P1 latency. Results: Eighty-five children were included (CI: n = 42; HA: n = 43). Mean P1 latency values did not differ significantly between groups for the /m/ stimulus (126.4 ± 29.13 ms vs. 126.4 ± 29.28 ms, p = 1.00), /g/ stimulus (106.5 ± 26.46 ms vs. 110.1 ± 29.49 ms, p = 0.55), or /t/ stimulus (114.7 ± 22.93 ms vs. 118.5 ± 27.19 ms, p = 0.48). Age at device fitting was comparable between groups (27.95 ± 9.10 vs. 26.88 ± 14.15 months, p = 0.68). The duration of device use was significantly longer in the HA group (48.02 ± 28.39 months) compared to the CI group (26.00 ± 15.92 months) (p < 0.001). Correlation analysis revealed no significant association between duration of device use and P1 latency for any stimulus (/m/: p = 0.28; /g/: p = 0.17; /t/: p = 0.09). Conclusions: When devices were fitted before 48 months of age and aided thresholds were optimized, unilateral cochlear implantation and bilateral conventional hearing aids showed comparable P1 latency values as an index of cortical auditory maturation. These findings suggest that early and adequate auditory stimulation may play an important role in supporting cortical auditory development in children with congenital hearing loss, although results should be interpreted within the context of individualized clinical management.

Imaging studies on neuronal network formation provide relevant information as to how the brain matures during adolescence. We used a novel imaging approach combining well-established MRI measures of local functional connectivity that jointly provide qualitatively different information relating to the functional structure of the cerebral cortex. To investigate the adolescent transition into adulthood, we comparatively assessed 169 preadolescents aged 8–12 years and 121 healthy adults. Whole-brain functional connectivity maps were generated using multi-distance measures of intracortical neural activity coupling defined within iso-distant local areas. Such Iso-Distant Average Correlation (IDAC) measures therefore represent the average temporal correlation of a given brain unit, or voxel, with other units situated at increasingly separated iso-distant intervals. The results indicated that between-group differences in the functional structure of the cerebral cortex are extensive and implicate part of the lateral prefrontal cortex, a medial frontal/anterior cingulate region, the superior parietal lobe extending to the somatosensory strip and posterior cingulate cortex, and local connections within the visual cortex, hippocampus, amygdala and insula. We thus provided detail of the cerebral cortex functional structure maturation during the transition to adulthood, which may serve to establish more accurate links between adolescent performance gains and cerebral cortex maturation. Remarkably, our study provides new information as to the cortical maturation processes in prefrontal areas relevant to executive functioning and rational learning, medial frontal areas playing an active role in the cognitive appraisal of emotion and anxiety, and superior parietal cortices strongly associated with bodily self-consciousness in the context of body image formation.

Background: Cortical folding during fetal brain development reflects neural matur-ation. Fetal growth restriction (FGR) may disrupt this process, potentially affecting neurodevelopmental outcomes. Although ultrasound enables noninvasive sulcal assessment, so normative data and objective tools are lacking. The purpose of the current study was to assess the impact of FGR on fetal cortical development using neurosonography and establish a third-trimester nomogram for cortical maturation. Methods: This prospective study included 425 singleton pregnancies (330 appropri-ate-for-gestational-age [AGA], 54 symmetrical FGR, and 41 asymmetrical FGR) at 28–36 weeks. Conducted at a Tehran tertiary center (2023–2024), the study included cases with normal anatomy and negative aneuploidy screening. Neurosonographic parameters including Sylvian fissure (SF), insula, parieto-occipital fissure (POF), cavum septum pellucidum (CSP) width, and ventricular diameter were measured and the ratios calculated relative to biparietal diameter (BPD). ANOVA and post-hoc tests were applied and statistical significance was set at p<0.05. Results: No significant differences in neurosonographic ratios (e.g., SF/Insula, POF/ BPD, CSPW/BPD) were found between AGA and FGR groups. However, unadjust-ed SF and insular depths were reduced in symmetrical FGR fetuses with head cir-cumference (HC) <10th percentile. Asymmetrical FGR showed no differences. A gestational-age-based nomogram was developed for AGA fetuses. Conclusion: While absolute sulcal measurements vary with head size in FGR, biometric adjustments (e.g., BPD ratios) improve cortical maturation assessment. The study supports ratio-based neurosonography and provides normative data for objective fetal brain evaluation.

Adult listeners perceive pitch with fine precision, with many adults capable of discriminating less than a 1 % change in fundamental frequency (F0). Although there is variability across individuals, this precise pitch perception is an ability ascribed to cortical functions that are also important for speech and music perception. Infants display neural immaturity in the auditory cortex, suggesting that pitch discrimination may improve throughout infancy. In two experiments, we tested the limits of F0 (pitch) and spectral centroid (timbre) perception in 66 infants and 31 adults. Contrary to expectations, we found that infants at both 3 and 7 months were able to reliably detect small changes in F0 in the presence of random variations in spectral content, and vice versa, to the extent that their performance matched that of adults with musical training and exceeded that of adults without musical training. The results indicate high fidelity of F0 and spectral-envelope coding in infants, implying that fully mature cortical processing is not necessary for accurate discrimination of these features. The surprising difference in performance between infants and musically untrained adults may reflect a developmental trajectory for learning natural statistical covariations between pitch and timbre that improves coding efficiency but results in degraded performance in adults without musical training when expectations for such covariations are violated.

Background Assessments of cortical development and identifying factors that may result in a poor prognosis for fetuses with isolated mild ventriculomegaly (IMVM) is a hot research topic. We aimed to perform a constant, detailed assessment of cortical development in IMVM fetuses using ultrasound and determine whether asymmetric cortical development occurred. Moreover, we aimed to estimate the prognosis of IMVM fetuses and compare the difference in the prognosis of IMVM fetuses presenting symmetric and asymmetric cortical maturation. Methods IMVM was diagnosed by regular ultrasound, neurosonography and fetal MRI. Genetic and TORCH examinations were conducted to exclude common genetic abnormalities and TORCH infection of fetuses. Ultrasound examinations were conducted at an interval of 2–3 weeks to record sulcus development in IMVM fetuses using a scoring system. The neonatal behavioral neurological assessment (NBNA), the Ages and Stages Questionnaire, Third Edition (ASQ-3) and the Bayley Scales of Infant Development, First Edition (BSID-I) were performed after birth. Results Forty fetuses with IMVM were included: twenty showed asymmetric cortical maturation and twenty showed symmetric cortical maturation. For IMVM fetuses presenting asymmetric cortical maturation, the mean gestational age (GA) at the first diagnosis of relatively delayed development was 24.23 weeks for the parieto-occipital sulcus, 24.71 weeks for the calcarine sulcus, and 26.43 weeks for the cingulate sulcus. All the sulci with delayed development underwent ‘catch-up growth’ and developed to the same grade as the sulci of the other hemisphere. The mean GA at which the two sides developed to the same grade was 29.40 weeks for the parieto-occipital sulcus, 29.30 weeks for the calcarine sulcus and 31.27 weeks for the cingulate sulcus. The NBNA, ASQ-3 and BSID-I scores of all patients were in the normal range. Conclusions IMVM fetuses may show mild asymmetric cortical maturation in the second trimester, but the relatively delayed sulci undergo ‘catch-up growth’. The neurodevelopment of IMVM fetuses presenting asymmetric cortical maturation and ‘catch-up growth’ is not statistically significantly different from IMVM fetuses presenting symmetric cortical maturation.

The developing cerebral cortex contains a distinct class of cells, subplate neurons, which form one of the first functional cortical circuits. Subplate neurons reside in the cortical white matter, receive thalamic inputs and project into the developing cortical plate, mostly to layer 4. Subplate neurons are present at key time points during development. Removal of subplate neurons profoundly affects cortical development. Subplate removal in visual cortex prevents the maturation of thalamocortical synapse, the maturation of inhibition in layer 4, the development of orientation selective responses in individual cortical neurons, and the formation of ocular dominance columns. In addition, monocular deprivation during development reveals that ocular dominance plasticity is paradoxical in the absence of subplate neurons. Because subplate neurons projecting to layer 4 are glutamatergic, these diverse deficits following subplate removal were hypothesized to be due to lack of feed-forward thalamic driven cortical excitation. A computational model of the developing thalamocortical pathway incorporating feed-forward excitatory subplate projections replicates both normal development and plasticity of ocular dominance as well as the effects of subplate removal. Therefore, we postulate that feed-forward excitatory projections from subplate neurons into the developing cortical plate enhance correlated activity between thalamus and layer 4 and, in concert with Hebbian learning rules in layer 4, allow maturational and plastic processes in layer 4 to commence. Thus subplate neurons are a crucial regulator of cortical development and plasticity, and damage to these neurons might play a role in the pathology of many neurodevelopmental disorders.

The auditory magnetic event-related fields (ERF) qualitatively change through the child development, reflecting maturation of auditory cortical areas. Clicks presented with long inter-stimulus interval produce distinct ERF components, and may appear useful to characterize immature EFR morphology in children. The present study is aimed to investigate morphology of the auditory ERFs in school-age children, as well as lateralization and repetition suppression of ERF components evoked by the clicks. School-age children and adults passively listened to pairs of click presented to the right ear, left ear or binaurally, with 8–11 s intervals between the pairs and a 1 s interval within a pair. Adults demonstrated a typical P50m/N100m response. Unlike adults, children had two distinct components preceding the N100m–P50m (at ~65 ms) and P100m (at ~100 ms). The P100m dominated the child ERF, and was most prominent in response to binaural stimulation. The N100m in children was less developed than in adults and partly overlapped in time with the P100m, especially in response to monaural clicks. Strong repetition suppression was observed for P50m both in children and adults, P100m in children and N100m in adults. Both children and adults demonstrated ERF amplitude and/or latency right hemispheric advantage effects that may reflect right hemisphere dominance for preattentive arousal processes. Our results contribute to the knowledge concerning development of auditory processing and its lateralization in children and have implications for investigation of the auditory evoked fields in developmental disorders.