Language Network Function in Young Children Born Very Preterm

Language deficits are reported in preterm born children across development. Recent neuroimaging studies have found functional alterations in large-scale brain networks underlying these language deficits, but the early childhood development of the language network has not been investigated. Here, we compared intrinsic language network connectivity in 4-year-old children born VPT and term-born controls, using defined language regions (Broca’s area, Wernicke’s areas, and their homologues in the right hemisphere). Resting-state functional magnetic resonance imaging (fMRI) was obtained, and the group differences in whole-brain connectivity were examined from each seed as well as correlations with language outcomes. We found significantly decreased functional connectivity in almost all language regions in children born VPT compared to their term controls. Notably, Broca’s area homologue in the right hemisphere emerged as a functional hub of decreased connectivity in VPT group, specifically to bilateral inferior frontal and supramarginal gyri; connectivity strength between Broca’s area homologue with the right supramarginal and the left inferior frontal gyri was associated with better language outcomes at 4 years of age. Wernicke’s area and its homologue also showed decreased inter-hemispheric connections to bilateral supramarginal gyri in the VPT group. Decreased intra- and inter-hemispheric connectivity among primary language regions suggests immature and altered function in the language network in children born VPT

Robotic Path-finding in Inverse Treatment Planning with Continuous Dose Delivery for Stereotactic Radiosurgery

Continuous dose delivery, or continuous path (CP) treatment, in stereotactic radiosurgery has been proven to improve the total treatment time, dose conformity, and dose distribution homogeneity over traditional step-and-shoot delivery. We develop several automated planning methods using robotic path-finding techniques to design CP treatments for SRS with Gamma Knife Perfexion. Using simultaneous localization and mapping (SLAM), we construct paths through the target that pass sufficiently close to a set of pre-selected isocentre locations. To solve SLAM, both the traditional extended Kalman filter (EKF) and incremental smoothing and mapping (iSAM) algorithms are investigated. Steering decision algorithms using heuristic scoring methods and robotic exploration techniques, specifically, frontiers, are investigated. Once a path is found, shot delivery from each sector is optimized along the path using inverse planning optimization. The SLAM methods consistently improve dose metrics and beam-on time compared to the clinical and an earlier graph-based Hamiltonian path CP planning approach.M.A.S

Robotic Path-finding in Inverse Treatment Planning with Continuous Dose Delivery for Stereotactic Radiosurgery

Continuous dose delivery, or continuous path (CP) treatment, in stereotactic radiosurgery has been proven to improve the total treatment time, dose conformity, and dose distribution homogeneity over traditional step-and-shoot delivery. We develop several automated planning methods using robotic path-finding techniques to design CP treatments for SRS with Gamma Knife Perfexion. Using simultaneous localization and mapping (SLAM), we construct paths through the target that pass sufficiently close to a set of pre-selected isocentre locations. To solve SLAM, both the traditional extended Kalman filter (EKF) and incremental smoothing and mapping (iSAM) algorithms are investigated. Steering decision algorithms using heuristic scoring methods and robotic exploration techniques, specifically, frontiers, are investigated. Once a path is found, shot delivery from each sector is optimized along the path using inverse planning optimization. The SLAM methods consistently improve dose metrics and beam-on time compared to the clinical and an earlier graph-based Hamiltonian path CP planning approach.M.A.S

Robotic Path-finding in Inverse Treatment Planning with Continuous Dose Delivery for Stereotactic Radiosurgery

Continuous dose delivery, or continuous path (CP) treatment, in stereotactic radiosurgery has been proven to improve the total treatment time, dose conformity, and dose distribution homogeneity over traditional step-and-shoot delivery. We develop several automated planning methods using robotic path-finding techniques to design CP treatments for SRS with Gamma Knife Perfexion. Using simultaneous localization and mapping (SLAM), we construct paths through the target that pass sufficiently close to a set of pre-selected isocentre locations. To solve SLAM, both the traditional extended Kalman filter (EKF) and incremental smoothing and mapping (iSAM) algorithms are investigated. Steering decision algorithms using heuristic scoring methods and robotic exploration techniques, specifically, frontiers, are investigated. Once a path is found, shot delivery from each sector is optimized along the path using inverse planning optimization. The SLAM methods consistently improve dose metrics and beam-on time compared to the clinical and an earlier graph-based Hamiltonian path CP planning approach.M.A.S

The developing relations between networks of cortical myelin and neurophysiological connectivity

Recent work identified that patterns of distributed brain regions sharing similar myeloarchitecture are related to underlying functional connectivity, demonstrating cortical myelin's plasticity to changes in functional demand. However, the changing relations between functional and structural architecture throughout child and adulthood are poorly understood. We show that structural covariance connectivity (T1-weighted/T2-weighted ratio) and functional connectivity (magnetoencephalography) exhibit nonlinear developmental changes. We then show significant relations between structural and functional connectivity, which have shared and distinct characteristics dependent on the neural oscillatory frequency. Increases in structure-function coupling are visible during the protracted myelination observed throughout childhood and adolescence and are followed by decreases near the onset of adulthood. Our work lays the foundation for understanding the mechanisms by which myeloarchitecture supports brain function, enabling future investigations into how clinical populations may deviate from normative patterns

Altered myelin maturation in four year old children born very preterm

Children born very preterm (VPT; <32 weeks gestational age [GA]) are at greater risk for a range of cognitive deficits that typically manifest at school age. Here we examine the hypothesis that these children have altered myelin maturational that can be detected by myelin sensitive MRI measures prior to school age. We included 33 four-year old children born VPT (mean GA; 28.7 weeks) and 23 four-year old full term (FT) children and completed magnetization transfer (MT), T1-weighted (T1-w) and T2-weighted (T1-w) magnetic resonance imaging as well as developmental assessments. Both MT ratio (MTR) and T1-w/T2-w ratio images were calculated, and group differences were probed using tract-based spatial statistics (TBSS) in white matter, and region of interest (ROI) analysis in white, subcortical gray and cortical gray matter. The relations between MTR and T1-w/T2-w ratio, as well as with developmental assessments, were investigated in all three brain divisions. In children born VPT, TBSS and ROI analysis revealed that both MTR and T1-w/T2-w ratio were significantly reduced in white matter compared to children born FT. ROI analysis showed reductions in T1-w/T2-w ratio in VPT children compared to FT children in the thalamus, putamen and amygdala, as well as in the occipital and temporal lobes. Across the VPT and FT children, T1-w/T2-w ratio and MTR were highly correlated across white, subcortical gray and cortical gray matter. Both measures correlated positively with developmental assessments in individual white matter tracts and cortical and subcortical ROIs, suggesting that higher MTR and T1-w/T2-w ratio is related to better cognitive performance. Together these findings are consistent with delayed myelination in VPT born children. Keywords: Magnetic resonance imaging, Preterm, T1-weighted/T2-weighted ratio, Magnetization transfer ratio, Myelin enhanced contras

Table_1_Characterising the spatial and oscillatory unfolding of Theory of Mind in adults using fMRI and MEG.DOCX

Theory of Mind (ToM) is a core social cognitive skill that refers to the ability to attribute mental states to others. ToM involves understanding that others have beliefs, thoughts and desires that may be different from one's own and from reality. ToM is crucial to predict behaviour and navigate social interactions. This study employed the complementary methodological advantages of both functional MRI (fMRI) and magnetoencephalography (MEG) to examine the neural underpinnings of ToM in adults. Twenty healthy adults were first recruited to rate and describe 28 videos (15s long), each containing three moving shapes designed to depict either social interactions or random motion (control condition). The first sample of adults produced consistent narratives for 6 of those social videos and of those, 4 social videos and 4 control videos were chosen to include in the neuroimaging study. Another sample of twenty-five adults were then recruited to complete the neuroimaging in MEG and fMRI. In fMRI, we found increased activation in frontal-parietal regions in the social compared to the control condition corroborating previous fMRI findings. In MEG, we found recruitment of ToM networks in the social condition in theta, beta and gamma bands. The right supramarginal and angular gyri (right temporal parietal junction), right inferior parietal lobe and right temporal pole were recruited in the first 5s of the videos. Frontal regions such as the superior frontal gyrus were recruited in the second time window (5–10s). Brain regions such as the bilateral amygdalae were also recruited (5–10s), indicating that various social processes were integrated in understanding the social videos. Our study is one of the first to combine multi-modal neuroimaging to examine the neural networks underlying social cognitive processes, combining the strengths of the spatial resolution of fMRI and temporal resolution of MEG. Understanding this information from both modalities helped delineate the mechanism by which ToM processing unfolds over time in healthy adults. This allows us to determine a benchmark against which clinical populations can be compared.</p

Datasheet1_Investigating heterogeneity across autism, ADHD, and typical development using measures of cortical thickness, surface area, cortical/subcortical volume, and structural covariance.pdf

IntroductionAttention-deficit/hyperactivity disorder (ADHD) and autism are multi-faceted neurodevelopmental conditions with limited biological markers. The clinical diagnoses of autism and ADHD are based on behavioural assessments and may not predict long-term outcomes or response to interventions and supports. To address this gap, data-driven methods can be used to discover groups of individuals with shared biological patterns.MethodsIn this study, we investigated measures derived from cortical/subcortical volume, surface area, cortical thickness, and structural covariance investigated of 565 participants with diagnoses of autism [n = 262, median(IQR) age = 12.2(5.9), 22% female], and ADHD [n = 171, median(IQR) age = 11.1(4.0), 21% female] as well neurotypical children [n = 132, median(IQR) age = 12.1(6.7), 43% female]. We integrated cortical thickness, surface area, and cortical/subcortical volume, with a measure of single-participant structural covariance using a graph neural network approach.ResultsOur findings suggest two large clusters, which differed in measures of adaptive functioning (χ2 = 7.8, P = 0.004), inattention (χ2 = 11.169, P 2 = 18.44, P 2 = 9.24, P = 0.002), age (χ2 = 70.87, P 2 = 105.6, P DiscussionThese clusters did not align with existing diagnostic labels, suggesting that brain structure is more likely to be associated with differences in adaptive functioning, IQ, and ADHD features.</p

Cortical Gyrification Morphology in ASD and ADHD: Implication for Further Similarities or Disorder-Specific Features?

Shared etiological pathways are suggested in ASD and ADHD given high rates of comorbidity, phenotypic overlap and shared genetic susceptibility. Given the peak of cortical gyrification expansion and emergence of ASD and ADHD symptomology in early development, we investigated gyrification morphology in 539 children and adolescents (6-17 years of age) with ASD (n=197) and ADHD (n=96) compared to typically developing controls (n=246) using the local Gyrification Index (lGI) to provide insight into contributing etiopathological factors in these two disorders. We also examined IQ effects and functional implications of gyrification by exploring the relation between lGI and ASD and ADHD symptomatology beyond diagnosis. General Linear Models yielded no group differences in lGI, and across groups, we identified an age-related decrease of lGI and greater lGI in females compared to males. No diagnosis-by-age interactions were found. Accounting for IQ variability in the model (n=484) yielded similar results. No significant associations were found between lGI and social communication deficits, repetitive and restricted behaviours, inattention or adaptive functioning. By examining both disorders and controls using shared methodology, we found no evidence of atypicality in gyrification as measured by the lGI in these conditions