RESUMO
The corpus callosum (CC) is a large white matter fiber bundle in the brain and is involved in various cognitive, sensory, and motor processes. While implicated in various developmental and psychiatric disorders, much is yet to be uncovered about the normal development of this structure, especially in young children. Additionally, while sexual dimorphism has been reported in prior literature, observations have not necessarily been consistent. In this study, we use morphometric measures including surface tensor-based morphometry (TBM) to investigate local changes in the shape of the CC in children between the ages of 12 and 60 months, in intervals of 12 months. We also analyze sex differences in each of these age groups. We observed larger significant clusters in the earlier ages between 12 v 24 m and between 48 v 60 m and localized differences in the anterior region of the body of the CC. Sex differences were most pronounced in the 12 m group. This study adds to the growing literature of work aiming to understand the developing brain and emphasizes the utility of surface TBM as a useful tool for analyzing regional differences in neuroanatomical morphometry.
Assuntos
Corpo Caloso , Caracteres Sexuais , Humanos , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/crescimento & desenvolvimento , Corpo Caloso/anatomia & histologia , Masculino , Feminino , Lactente , Pré-Escolar , Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Processamento de Imagem Assistida por Computador/métodosRESUMO
Our ability to merge information from different senses into a unified percept is a crucial perceptual process for efficient interaction with our multisensory environment. Yet, the developmental process underlying how the brain implements multisensory integration (MSI) remains poorly known. This cross-sectional study aims to characterize the developmental patterns of audiovisual events in 131 individuals aged from 3 months to 30 years. Electroencephalography (EEG) was recorded during a passive task, including simple auditory, visual, and audiovisual stimuli. In addition to examining age-related variations in MSI responses, we investigated Event-Related Potentials (ERPs) linked with auditory and visual stimulation alone. This was done to depict the typical developmental trajectory of unisensory processing from infancy to adulthood within our sample and to contextualize the maturation effects of MSI in relation to unisensory development. Comparing the neural response to audiovisual stimuli to the sum of the unisensory responses revealed signs of MSI in the ERPs, more specifically between the P2 and N2 components (P2 effect). Furthermore, adult-like MSI responses emerge relatively late in the development, around 8 years old. The automatic integration of simple audiovisual stimuli is a long developmental process that emerges during childhood and continues to mature during adolescence with ERP latencies decreasing with age.
Assuntos
Estimulação Acústica , Percepção Auditiva , Eletroencefalografia , Potenciais Evocados , Estimulação Luminosa , Percepção Visual , Humanos , Adulto , Feminino , Masculino , Lactente , Eletroencefalografia/métodos , Percepção Auditiva/fisiologia , Percepção Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Adulto Jovem , Potenciais Evocados/fisiologia , Estimulação Luminosa/métodos , Estudos Transversais , Estimulação Acústica/métodos , Encéfalo/fisiologiaRESUMO
OBJECTIVE: This systematic review, performed in accordance with the PRISMA guidelines, seeks to summarize the interventions that have been developed in order to improve executive functioning and attention in children born prematurely. METHODS: The PICOS framework helped guide the structure and relevant terms selected for the study. Electronic systematic searches of the databases PubMed (NLM), Ovid Medline, Ovid All EBM Reviews, Ovid Embase, and Ovid PsycINFO were completed in March 2022. This review focuses on interventions that target attention and executive functioning in prematurely born children between birth and 12 years old, with outcome measures assessed between 3 and 12 years old, even if the age range in the study can exceed our own parameters. Data extraction included sample characteristics, country of recruitment, type of intervention, description of the intervention group and control group, outcome measures, and overall results. An assessment of the quality of methodology of studies was performed through an adaptation of the Downs and Black checklist for both randomized and nonrandomized studies in healthcare interventions. An assessment of the risk of bias was also presented using the Cochrane risk of bias tool for randomized trials 2.0. RESULTS: A total of 517 premature children received an intervention at some point between birth and early adolescence. Eleven different interventions were assessed in 17 studies, with rating of the quality of methodology and outcomes ranging from lower quality studies (44% quality rating) to robust studies (96% quality rating) in terms of reporting standards, external and internal validity, and power. Five of those studies focused on interventions administered in the neonatal intensive care unit or shortly postdischarge (e.g., the Mother-Infant Transaction Program and the Newborn Individualized Developmental Care and Assessment Program, documented in two articles each [11%] or the Infant Behavioral Assessment and Intervention Program assessed in one study [about 5%]), while 12 articles reported on interventions administered between the ages of 1.5-12 years old [mostly computerized cognitive training programs such as Cogmed (23%) and BrainGame Brian (17%)]. Of the 17 articles examined, 12 (70%) showed positive short-term outcomes postintervention and 3 (17%) demonstrated positive long-term results with small to large effect sizes (0.23-2.3). Among included studies, 50% showed an overall high risk of bias, 21.4% showed some concerns, and 28.6% were low risk of bias. CONCLUSIONS: Due to the heterogeneity of the programs reviewed, the presented findings should be interpreted as descriptive results. A careful and individualized selection from the various available interventions should be made based on the target population (i.e., age at intervention administration and outcome testing) before implementing these program protocols in clinical settings.
RESUMO
OBJECTIVE: To characterize the neuropsychological outcome of children with congenital heart disease (CHD) at age 5 years; the stability of cognitive and language abilities across childhood; and to identify early neurodevelopmental markers of neuropsychological outcomes in these children. STUDY DESIGN: Five-year-old children (n = 55) with complex CHD were assessed using standardized and comprehensive neuropsychological measures. Stability of language and cognitive performance was assessed by comparing standardized scores between ages 1, 2, and 5 years old. Association between 5-year-old skills and scores obtained in early childhood was studied to identify potential early markers of preschool performance. Receiver operating characteristic curves were used to evaluate the classification accuracy of Bayley Scales of Infant Development, Third Edition scales in identifying later impairments. RESULTS: At age 5 years, our cohort obtained scores significantly below the norms on most developmental domains, with 35% to 65% of participants showing impaired short-term/working memory, attention, and preacademic skills. Developmental patterns measured between ages 1 and 5 years were different for cognitive and language domains, with a decline with age for cognitive functioning and stable results for expressive language. The Bayley Scales of Infant Development, Third Edition language scores at age 2 years provided a good predictive value in identifying children with impaired language at age 5 years. CONCLUSIONS: In our cohort, we found a high prevalence of impairments affecting higher-order cognitive domains. Although language difficulties can be detected as early as 2 years of age, other neuropsychological impairments, such as attention and pre-academic skills, only appear later during development, which reinforces the need for long-term monitoring and systematic assessment before school entry.
Assuntos
Deficiências do Desenvolvimento/etiologia , Cardiopatias Congênitas/complicações , Pré-Escolar , Estudos de Coortes , Deficiências do Desenvolvimento/diagnóstico , Feminino , Humanos , Lactente , Masculino , Testes Neuropsicológicos , Curva ROCRESUMO
Unilateral hippocampal atrophy (HA) is considered as a precursor of mesial temporal sclerosis (MTS) in some patients with temporal lobe epilepsy. However, in other cases, it has been suggested that HA without MTS may constitute a distinct epileptic entity. Hippocampal atrophy without MTS was defined as HA without T2-weighted hyperintensity, loss of internal architecture, or associated lesion seen on the MRI data. To date, no study has focused on the cognitive pattern of children with epilepsy with HA without MTS. The objectives of the present study were to characterize the cognitive profile of these children and to investigate the presence (or the absence) of material-specific memory deficits in these young patients, as found in patients with MTS. Toward this end, 16 young patients with epilepsy with either left or right HA without MTS completed a set of neuropsychological tests, assessing overall intelligence, verbal memory and nonverbal memory, and some aspects of attention and executive functions. Results showed normal intellectual functioning without specific memory deficits in these patients. Furthermore, comparison between patients with left HA and patients with right HA failed to reveal a material-specific lateralized memory pattern. Instead, attention and executive functions were found to be impaired in most patients. These results suggest that HA may constitute a distinct epileptic entity, and this information may help health-care providers initiate appropriate and timely interventions.
Assuntos
Epilepsia do Lobo Temporal/psicologia , Hipocampo/patologia , Adolescente , Idade de Início , Atrofia , Atenção , Criança , Eletroencefalografia , Epilepsia do Lobo Temporal/complicações , Feminino , Humanos , Testes de Inteligência , Deficiências da Aprendizagem/etiologia , Deficiências da Aprendizagem/psicologia , Imageamento por Ressonância Magnética , Masculino , Memória , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Testes Neuropsicológicos , Esclerose , Aprendizagem Verbal , Adulto JovemRESUMO
The prenatal and neonatal periods are two of the most important developmental stages of the human brain. It is therefore crucial to understand normal brain development and how early connections are established during these periods, in order to advance the state of knowledge on altered brain development and eventually identify early brain markers of neurodevelopmental disorders and diseases. In this systematic review (Prospero ID: CRD42024511365), we compiled resting state functional magnetic resonance imaging (fMRI) studies in healthy fetuses and neonates, in order to outline the main characteristics of typical development of the functional brain connectivity during the prenatal and neonatal periods. A systematic search of five databases identified a total of 12 573 articles. Of those, 28 articles met pre-established selection criteria based determined by the authors after surveying and compiling the major limitations reported within the literature. Inclusion criteria were: (1) resting state studies; (2) presentation of original results; (3) use of fMRI with minimum one Tesla; (4) a population ranging from 20 weeks of GA to term birth (around 37-42 weeks of PMA); (5) singleton pregnancy with normal development (absence of any complications known to alter brain development). Exclusion criteria were: (1) preterm studies; (2) post-mortem studies; (3) clinical or pathological studies; (4) twin studies; (5) papers with a sole focus on methodology (i.e. focused on tool and analysis development); (6) volumetric studies; (7) activation map studies; (8) cortical analysis studies; (9) conference papers. A risk of bias assessment was also done to evaluate each article's methodological rigor. 1877 participants were included across all the reviewed articles. Results consistently revealed a developmental gradient of increasing functional brain connectivity from posterior to anterior regions and from proximal-to-distal regions. A decrease in local small-world organization shortly after birth was also observed; small-world characteristics were present in fetuses and newborns, but appeared weaker in the latter group. Also, the posterior-to-anterior gradient could be associated with earlier development of the sensorimotor networks in the posterior regions while more complex higher-order networks (e.g. attention-related) mature later in the anterior regions. The main limitations of this systematic review stem from the inherent limitations of functional imaging in fetuses, mainly: unevenly distributed populations and limited sample sizes; fetal movements in the womb and other imaging obstacles; and a large voxel resolution when imaging a small brain. Another limitation specific to this review is the relatively small number of included articles compared to very a large search result, which may have led to relevant articles having been overlooked.
Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/crescimento & desenvolvimento , Recém-Nascido , Gravidez , Feminino , Desenvolvimento Fetal/fisiologia , Feto/diagnóstico por imagemRESUMO
OBJECTIVE: We investigated how electroencephalography (EEG) quantitative measures and dysglycemia relate to neurodevelopmental outcomes following neonatal encephalopathy (NE). METHODS: This retrospective study included 90 neonates with encephalopathy who received therapeutic hypothermia. EEG absolute spectral power was calculated during post-rewarming and 2-month follow-up. Measures of dysglycemia (hypoglycemia, hyperglycemia, and glycemic lability) and glucose variability were computed for the first 48 h of life. We evaluated the ability of EEG and glucose measures to predict neurodevelopmental outcomes at ≥ 18 months, using logistic regressions (with area under the receiver operating characteristic [AUROC] curves). RESULTS: The post-rewarming global delta power (average all electrodes), hyperglycemia and glycemic lability predicted moderate/severe neurodevelopmental outcome separately (AUROC = 0.8, 95%CI [0.7,0.9], p < .001) and even more so when combined (AUROC = 0.9, 95%CI [0.8,0.9], p < .001). After adjusting for NE severity and magnetic resonance imaging (MRI) brain injury, only global delta power remained significantly associated with moderate/severe neurodevelopmental outcome (odds ratio [OR] = 0.9, 95%CI [0.8,1.0], p = .04), gross motor delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), global developmental delay (OR = 0.9, 95%CI [0.8,1.0], p = .04), and auditory deficits (OR = 0.9, 95%CI [0.8,1.0], p = .03). CONCLUSIONS: In NE, global delta power post-rewarming was predictive of outcomes at ≥ 18 months. SIGNIFICANCE: EEG markers post-rewarming can aid prediction of neurodevelopmental outcomes following NE.
Assuntos
Eletroencefalografia , Hipotermia Induzida , Humanos , Masculino , Feminino , Recém-Nascido , Eletroencefalografia/métodos , Estudos Retrospectivos , Transtornos do Neurodesenvolvimento/fisiopatologia , Transtornos do Neurodesenvolvimento/etiologia , Transtornos do Neurodesenvolvimento/diagnóstico , Hiperglicemia/fisiopatologia , Hiperglicemia/complicações , Hipoglicemia/fisiopatologia , Hipoglicemia/complicações , Encefalopatias/fisiopatologia , Glicemia/metabolismo , LactenteRESUMO
Neurodevelopmental disabilities affect up to 50% of survivors of congenital heart disease (CHD). Language difficulties are frequently identified during preschool period and can lead to academic, social, behavioral, and emotional difficulties. Structural brain alterations are associated with poorer neurodevelopmental outcomes in patients with CHD during infancy, childhood, and adolescence. However, evidence is lacking about the functional brain activity in children with CHD and its relationship with neurodevelopment. This study therefore aimed to characterize brain responses during a passive story-listening task in 3-year-old children with CHD, and to investigate the relationship between functional brain patterns of language processing and neurodevelopmental outcomes. To do so, we assessed hemodynamic concentration changes, using functional near-infrared spectroscopy (fNIRS), and neurodevelopmental outcomes, using the Wechsler Preschool and Primary Scale of Intelligence - 4th Edition (WPPSI-IV), in children with CHD (n = 19) and healthy controls (n = 23). Compared to their healthy peers, children with CHD had significantly lower scores on the Verbal comprehension index (VCI), the Vocabulary acquisition index (VAI), the General ability index (GAI), and the Information and the Picture Naming subtests of the WPPSI-IV. During the passive story-listening task, healthy controls showed significant hemodynamic brain responses in the temporal and the temporal posterior regions, with stronger activation in the temporal posterior than in the temporal regions. In contrast, children with CHD showed reduced activation in the temporal posterior regions compared to controls, with no difference of activation between regions. Reduced brain responses in the temporal posterior regions were also correlated with lower neurodevelopmental outcomes in both groups. This is the first study that reveals reduced brain functional responses in preschoolers with CHD during a receptive language task. It also suggests that the temporal posterior activation could be a potential brain marker of cognitive development. These findings provide support for the feasibility of identifying brain correlates of neurodevelopmental vulnerabilities in children with CHD.
Assuntos
Cardiopatias Congênitas , Pré-Escolar , Adolescente , Humanos , Criança , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico por imagem , Cardiopatias Congênitas/psicologia , Encéfalo/diagnóstico por imagem , Emoções , Cognição , VocabulárioRESUMO
INTRODUCTION: Preschoolers and school-aged children with congenital heart disease (CHD) are at higher risk of attention deficit hyperactivity disorder (ADHD) compared with the general population. To this day, no randomised controlled trial (RCT) aiming to improve attention has been conducted in young children with CHD. There is emerging evidence indicating that parent-child yoga interventions improve attention and reduce ADHD symptoms in both typically developing and clinical populations. METHODS AND ANALYSIS: This is a single-blind, two-centre, two-arm trial during which 24 children with CHD and their parents will be randomly assigned to (1) a parent-child yoga intervention in addition to standard clinical care or (2) standard clinical care alone. All participants will undergo standardised assessments: (1) at baseline, (2) immediately post-treatment and (3) 6 months post-treatment. Descriptive statistics will be used to estimate the feasibility and neurodevelopmental outcomes. This feasibility study will evaluate: (1) recruitment capacity; (2) retention, drop-out and withdrawal rates during the yoga programme and at the 6-month follow-up; (3) adherence to the intervention; (4) acceptability of the randomisation process by families; (5) heterogeneity in the delivery of the intervention between instructors and use of home-based exercises between participants; (6) proportion of missing data in the neurodevelopmental assessments and (7) SD of primary outcomes of the full RCT in order to determine the future appropriate sample size. ETHICS AND DISSEMINATION: Ethical approval has been obtained by the Research Ethics Board of the Sainte-Justine University Hospital. The findings will be disseminated in peer-reviewed journals and conferences and presented to the Canadian paediatric grand round meetings. TRIAL REGISTRATION NUMBER: NCT05997680.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Cardiopatias Congênitas , Yoga , Humanos , Criança , Pré-Escolar , Estudos de Viabilidade , Canadá , Cardiopatias Congênitas/complicações , Relações Pais-FilhoRESUMO
Survivors of complex forms of congenital heart disease (CHD)∗ are at high risk of neurodevelopmental disabilities. Neuroimaging studies have pointed to brain anomalies and immature networks in infants with CHD, yet less is known about their functional network topology and associations with neurodevelopment. To characterize the functional network topology in 4-month-old infants with repaired CHD, we compared graph theory metrics measured using resting-state functional near-infrared spectroscopy (rs-fNIRS) between infants with CHD (n = 22) and healthy controls (n = 30). We also investigated the moderating effect of graph theory metrics on the relationship between group (CHD vs. Controls) and developmental outcomes at 24 months. At 4 months, both groups presented similar functional brain network topology. At 24 months, children with CHD had lower scores on the language scale and the expressive communication subscale of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III), as well as lower scores on the Grammatical Form scale of the MacArthur-Bates Communicative Development Inventory (MBCDI). The relationship between group and expressive language was moderated by the normalized characteristic path length (λ) and the degree (k). Although infants with CHD have functional brain topology similar to that of healthy controls, our findings suggest that they do not benefit from an optimal functional brain organization in comparison with healthy infants.
Assuntos
Encefalopatias , Cardiopatias Congênitas , Lactente , Humanos , Encéfalo/diagnóstico por imagem , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/diagnóstico por imagem , Encefalopatias/complicaçõesRESUMO
OBJECTIVE: Children born with congenital heart disease (CHD) are at an increased risk for various neurodevelopmental impairments. However, little is known regarding social outcomes associated with CHD, particularly during early childhood. The present study aimed to characterize the sociocognitive profile and to assess the contribution of language, executive functions (EF), and social cognition to social competence (SC) in preschoolers with CHD. METHOD: Five-year-old children with CHD (n = 55) completed a standardized neuropsychological assessment. Performance on sociocognitive skills was compared to test norms using one-sample t tests. Hierarchical regression was conducted to examine the associations between language skills, affect recognition (AR), theory of mind (ToM), EF (performance-based and parent-rated), and social competence. RESULTS: Children with CHD performed significantly worse than norms in language and ToM, whereas EF and social competence appeared generally preserved in our sample. In hierarchical regression analysis, cognitive functions (language score, AR, ToM, EF performance) accounted for a significant 24.3% of the variance. Parent-rated EF added another 24.8% to the total explained variance. CONCLUSIONS: These findings provide new evidence for understanding social cognition and competence among preschoolers with CHD, showing vulnerability in social cognition and language skills but not in social competence more generally. The model suggests a combined contribution of social cognition, language, and EF on social outcomes. Remedial programs addressing these intervention targets could be useful in promoting social development in this vulnerable population. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Assuntos
Cardiopatias Congênitas , Teoria da Mente , Criança , Pré-Escolar , Cognição , Função Executiva , Cardiopatias Congênitas/complicações , Humanos , Testes Neuropsicológicos , Cognição SocialRESUMO
Objectives: This retrospective cohort study investigates how parenting stress, measured at 4 months of age by use of a classic three-dimensional parent-reported scale (Parenting Stress Index, 4th Ed. or PSI-4), can predict anxiety symptoms and quality of sleep at 24 months in toddlers with congenital heart disease (CHD). Study Design: Sixty-six toddlers with CHD followed at our cardiac neurodevelopmental follow-up clinic were included in this study. As part of their systematic developmental assessment program, parents completed questionnaires on their stress level (PSI-4) when their child was 4 months old, and on their child's anxiety symptoms and quality of sleep at 24 months. Eight multiple linear regression models were built on the two measures collected at 24 months using the PSI-4 scores collected at 4 months. For each measure, four models were built from the PSI-4 total score and its three subscales (Parental Distress, Parent-Child Dysfunctional Interaction, Difficult Child), controlling for sex and socioeconomic status. Results: The PSI-4 Difficult Child subscale, which focuses on parenting anxiety related to the child's behavioral problems and poor psychosocial adjustment, accounted for 17% of the child's anxiety symptoms at 24 months. The two other PSI-4 subscales (Parental Distress and Parent-Child Dysfunctional Interaction) and the PSI-4 total score did not contribute significantly to the models. None of the four regression models on perceived quality of sleep were significant. It is important to note that 33% of parents responded defensively to the PSI-4. Conclusions: Parenting stress related to the child's behavioral problems and poor psychosocial adjustment, measured when the child is 4 months old, is associated with the child's ulterior anxiety symptoms. As very few standardized tools are available to assess the behavioral and psychoaffective development of infants, this study highlights the importance of early psychosocial screening in parents of infants with CHD. The high rate of significant Defensive Responding Indices reminds us to not take parent reports at face value, as their actual stress levels might be higher.
RESUMO
Characterizing the neuroanatomical correlates of brain development is essential in understanding brain-behavior relationships and neurodevelopmental disorders. Advances in brain MRI acquisition protocols and image processing techniques have made it possible to detect and track with great precision anatomical brain development and pediatric neurologic disorders. In this chapter, we provide a brief overview of the modern neuroimaging techniques for pediatric brain development and review key normal brain development studies. Characteristic disorders affecting neurodevelopment in childhood, such as prematurity, attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), epilepsy, and brain cancer, and key neuroanatomical findings are described and then reviewed. Large datasets of typically developing children and children with various neurodevelopmental conditions are now being acquired to help provide the biomarkers of such impairments. While there are still several challenges in imaging brain structures specific to the pediatric populations, such as subject cooperation and tissues contrast variability, considerable imaging research is now being devoted to solving these problems and improving pediatric data analysis.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno do Espectro Autista , Encéfalo/diagnóstico por imagem , Criança , Humanos , Imageamento por Ressonância Magnética , NeuroimagemRESUMO
Several attempts have been made in the past few years to develop and implement an automated segmentation of neonatal brain structural MRI. However, accurate automated MRI segmentation remains challenging in this population because of the low signal-to-noise ratio, large partial volume effects and inter-individual anatomical variability of the neonatal brain. In this paper, we propose a learning method for segmenting the whole brain cortical grey matter on neonatal T2-weighted images. We trained our algorithm using a neonatal dataset composed of 3 full-term and 4 preterm infants scanned at term equivalent age. Our segmentation pipeline combines the FAST algorithm from the FSL library software and a Bayesian segmentation approach to create a threshold matrix that minimizes the error of mislabeling brain tissue types. Our method shows promising results with our pilot training set. In both preterm and full-term neonates, automated Bayesian segmentation generates a smoother and more consistent parcellation compared to FAST, while successfully removing the subcortical structure and cleaning the edges of the cortical grey matter. This method show promising refinement of the FAST segmentation by considerably reducing manual input and editing required from the user, and further improving reliability and processing time of neonatal MR images. Further improvement will include a larger dataset of training images acquired from different manufacturers.
RESUMO
This study assessed whether the neonatal brain recruits different neural networks for native and non-native languages at birth. Twenty-seven one-day-old full-term infants underwent functional near-infrared spectroscopy (fNIRS) recording during linguistic and non-linguistic stimulation. Fourteen newborns listened to linguistic stimuli (native and non-native language stories) and 13 newborns were exposed to non-linguistic conditions (native and non-native stimuli played in reverse). Comparisons between left and right hemisphere oxyhemoglobin (HbO2) concentration changes over the temporal areas revealed clear left hemisphere dominance for native language, whereas non-native stimuli were associated with right hemisphere lateralization. In addition, bilateral cerebral activation was found for non-linguistic stimulus processing. Overall, our findings indicate that from the first day after birth, native language and prosodic features are processed in parallel by distinct neural networks.
Assuntos
Encéfalo/fisiologia , Lateralidade Funcional , Multilinguismo , Psicolinguística , Percepção da Fala/fisiologia , Estimulação Acústica , Encéfalo/crescimento & desenvolvimento , Mapeamento Encefálico , Feminino , Humanos , Recém-Nascido , Masculino , Testes Neuropsicológicos , Espectroscopia de Luz Próxima ao Infravermelho/métodosRESUMO
A considerable number of cognitive processes depend on the integration of multisensory information. The brain integrates this information, providing a complete representation of our surrounding world and giving us the ability to react optimally to the environment. Infancy is a period of great changes in brain structure and function that are reflected by the increase of processing capacities of the developing child. However, it is unclear if the optimal use of multisensory information is present early in childhood or develops only later, with experience. The first part of this review has focused on the typical development of multisensory integration (MSI). We have described the two hypotheses on the developmental process of MSI in neurotypical infants and children, and have introduced MSI and its neuroanatomic correlates. The second section has discussed the neurodevelopmental trajectory of MSI in cognitively-challenged infants and children. A few studies have brought to light various difficulties to integrate sensory information in children with a neurodevelopmental disorder. Consequently, we have exposed certain possible neurophysiological relationships between MSI deficits and neurodevelopmental disorders, especially dyslexia and attention deficit disorder with/without hyperactivity.
RESUMO
Because nervous system development may be affected by prematurity, many prematurely born children present language or cognitive disorders at school age. The goal of this study is to investigate whether these impairments can be identified early in life using electrophysiological auditory event-related potentials (AERPs) and mismatch negativity (MMN). Brain responses to speech and non-speech stimuli were assessed in prematurely born children to identify early electrophysiological markers of language and cognitive impairments. Participants were 74 children (41 full-term, 33 preterm) aged 3, 12, and 36 months. Pre-attentional auditory responses (MMN and AERPs) were assessed using an oddball paradigm, with speech and non-speech stimuli presented in counterbalanced order between participants. Language and cognitive development were assessed using the Bayley Scale of Infant Development, Third Edition (BSID-III). Results show that preterms as young as 3 months old had delayed MMN response to speech stimuli compared to full-terms. A significant negative correlation was also found between MMN latency to speech sounds and the BSID-III expressive language subscale. However, no significant differences between full-terms and preterms were found for the MMN to non-speech stimuli, suggesting preserved pre-attentional auditory discrimination abilities in these children. Identification of early electrophysiological markers for delayed language development could facilitate timely interventions.
Assuntos
Potenciais Evocados Auditivos/fisiologia , Recém-Nascido Prematuro/fisiologia , Desenvolvimento da Linguagem , Idioma , Fala/fisiologia , Estimulação Acústica , Fatores Etários , Percepção Auditiva , Mapeamento Encefálico , Pré-Escolar , Eletroencefalografia , Humanos , Lactente , Testes Neuropsicológicos , Fonética , Tempo de Reação/fisiologia , Retenção Psicológica/fisiologia , Estatísticas não ParamétricasRESUMO
The development of language hemispheric specialization is not well understood in young children, especially regarding expressive language functions. In this study, we investigated age-related changes in expressive language lateralization patterns in a population of children (3-6 and 7-10 years old), adolescents (11-16 years old), and young adults (19-30 years old). During functional near-infrared spectroscopy recordings, all participants performed a verbal fluency task, which consisted in naming as many words as possible belonging to a given semantic category. Hemoglobin concentration changes were measured in bilateral frontal and temporal cortical areas. During the language task, results showed a strong left hemisphere response along with weaker right hemisphere activation in all groups. Age-related increases in hemodynamic responses were found bilaterally, with younger children showing smaller hemodynamic responses than adolescents and adults in both hemispheres. Overall, these findings confirm that a left hemisphere specialization is already established in young children and persists through adulthood. Early left hemisphere specialization for expressive language suggests that language development hinges on structural and functional properties of the human brain with little reorganization occurring with development.
Assuntos
Lobo Frontal/fisiologia , Lateralidade Funcional/fisiologia , Neuroimagem Funcional/métodos , Desenvolvimento da Linguagem , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Lobo Temporal/fisiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Lobo Frontal/crescimento & desenvolvimento , Humanos , Masculino , Lobo Temporal/crescimento & desenvolvimento , Adulto JovemRESUMO
During child development, physiological changes occur in the auditory cortex, which are reflected by differences in the electrophysiological signals. This study aimed to examine the age-related changes of the Mismatch Negativity component (MMN) in response to speech and non-speech stimuli in a cross-sectional design. Results revealed distinct patterns of activation according to stimulus type and age. Age-related differences for tone discrimination occurred earlier in children's development than did the discriminative process for speech sounds. Therefore, networks involved in speech processing are still immature in late childhood and may be more vulnerable to physiological changes.
Assuntos
Encéfalo/fisiologia , Potenciais Evocados Auditivos/fisiologia , Desenvolvimento da Linguagem , Fonética , Percepção da Fala/fisiologia , Estimulação Acústica/métodos , Adolescente , Criança , Desenvolvimento Infantil , Pré-Escolar , Estudos Transversais , Discriminação Psicológica/fisiologia , Eletroencefalografia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Adulto JovemRESUMO
Since the seminal work of Broca in 1861, it is well established that language is essentially processed in the left hemisphere. However, the origin of hemispheric specialization remains controversial. Some authors posit that language lateralization is genetically determined, while others have suggested that hemispheric specialization develops with age. Tenants of the latter view have further suggested that the adult pattern of left hemispheric specialization is achieved by means of callosal inhibition of homologous speech areas in the right hemisphere during ontogeny. According to this hypothesis, one would expect language to develop bilaterally in the acallosal brain. A recent functional magnetic resonance imaging (fMRI) study in one patient with agenesis of the corpus callosum suggests that this might indeed be the case (Riecker et al., 2007). However, given the large anatomic and functional variability in the population of subjects with agenesis of the corpus callosum, this finding needs to be more extensively replicated. In the present study, we explored language lateralization in six individuals with agenesis of the corpus callosum using an fMRI protocol which included a syntactic decision task and a sub-vocal verbal fluency task. Two neurologically intact control groups, one comparable to the acallosals in terms of IQ, age and education (n=6) and one group with a high IQ (n=5), performed the same tasks. No differences were found between language lateralization of the subjects with agenesis of the corpus callosum and the control groups in the receptive speech task. However, for expressive speech, the groups differed with respect to frontal activations, with the acallosal participants showing a more bilateral pattern of activation than the high-IQ participants only. No differences were found for temporal regions. Overall, these results indicate that the corpus callosum is not essential for the establishment of lateralized language functions.