Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.449
Filtrar
1.
BMC Pediatr ; 24(1): 318, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38720281

RESUMO

Reading learning disability (RLD) is characterized by a specific difficulty in learning to read that is not better explained by an intellectual disability, lack of instruction, psychosocial adversity, or a neurological disorder. According to the domain-general hypothesis, a working memory deficit is the primary problem. Working memory in this population has recently been linked to altered resting-state functional connectivity within the default mode network (DMN), salience network (SN), and frontoparietal network (FPN) compared to that in typically developing individuals. The main purpose of the present study was to compare the within-network functional connectivity of the DMN, SN, FPN, and reading network in two groups of children with RLD: a group with lower-than-average working memory (LWM) and a group with average working memory (AWM). All subjects underwent resting-state functional magnetic resonance imaging (fMRI), and data were analyzed from a network perspective using the network brain statistics framework. The results showed that the LWM group had significantly weaker connectivity in a network that involved brain regions in the DMN, SN, and FPN than the AWM group. Although there was no significant difference between groups in reading network in the present study, other studies have shown relationship of the connectivity of the angular gyrus, supramarginal gyrus, and inferior parietal lobe with the phonological process of reading. The results suggest that although there are significant differences in functional connectivity in the associated networks between children with LWM and AWM, the distinctive cognitive profile has no specific effect on the reading network.


Assuntos
Dislexia , Imageamento por Ressonância Magnética , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Criança , Masculino , Feminino , Dislexia/fisiopatologia , Dislexia/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Leitura , Estudos de Casos e Controles
2.
Sci Rep ; 14(1): 10249, 2024 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-38704429

RESUMO

Phonological awareness (PA) is at the foundation of reading development: PA is introduced before formal reading instruction, predicts reading development, is a target for early intervention, and is a core mechanism in dyslexia. Conventional approaches to assessing PA are time-consuming and resource intensive: assessments are individually administered and scoring verbal responses is challenging and subjective. Therefore, we introduce a rapid, automated, online measure of PA-The Rapid Online Assessment of Reading-Phonological Awareness-that can be implemented at scale without a test administrator. We explored whether this gamified, online task is an accurate and reliable measure of PA and predicts reading development. We found high correlations with standardized measures of PA (CTOPP-2, r = .80) for children from Pre-K through fourth grade and exceptional reliability (α = .96). Validation in 50 first and second grade classrooms showed reliable implementation in a public school setting with predictive value of future reading development.


Assuntos
Dislexia , Fonética , Leitura , Humanos , Criança , Feminino , Masculino , Dislexia/diagnóstico , Dislexia/fisiopatologia , Reprodutibilidade dos Testes , Conscientização , Pré-Escolar
3.
Cereb Cortex ; 34(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38664864

RESUMO

The Simple View of Reading model suggests that intact language processing and word decoding lead to proficient reading comprehension, with recent studies pointing at executive functions as an important component contributing to reading proficiency. Here, we aimed to determine the underlying mechanism(s) for these changes. Participants include 120 8- to 12-year-old children (n = 55 with dyslexia, n = 65 typical readers) trained on an executive functions-based reading program, including pre/postfunctional MRI and behavioral data collection. Across groups, improved word reading was related to stronger functional connections within executive functions and sensory networks. In children with dyslexia, faster and more accurate word reading was related to stronger functional connections within and between sensory networks. These results suggest greater synchronization of brain systems after the intervention, consistent with the "neural noise" hypothesis in children with dyslexia and support the consideration of including executive functions as part of the Simple View of Reading model.


Assuntos
Dislexia , Função Executiva , Imageamento por Ressonância Magnética , Leitura , Humanos , Criança , Dislexia/fisiopatologia , Dislexia/psicologia , Dislexia/diagnóstico por imagem , Função Executiva/fisiologia , Masculino , Feminino , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia
4.
Dyslexia ; 30(2): e1767, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38684454

RESUMO

Several studies have shown that children with dyslexia (DYS), in addition to their reading and spelling deficits, encounter handwriting difficulties that are still poorly understood in terms of their nature and origin. The present study aimed to better understand the handwriting difficulties of children with DYS by comparing their handwriting quality and speed in two tasks, a dictation task and an alphabet task, which required fewer spelling skills than the dictation task. Twenty-nine French-speaking children (Mage = 9.5 years) participated in the study, including 18 children with DYS and nine typically developing (TD) children matched on chronological age. The children performed control tasks, a dictation task with words varying in graphic and orthographic complexity and an alphabet writing task. Accuracy, handwriting quality (legibility), and fluency (speed, writing and pause time) were carefully measured using a digital tablet. GLMM analysis and t tests showed that children with DYS made more aesthetic errors (handwriting quality) in both the dictation and alphabet task than TD children. They also wrote more slowly than TD children in the alphabet task (speed, pause time). These findings suggest that children with DYS present handwriting difficulties, even in a simple alphabet task. In dictation, they seem to favour speed at the expense of handwriting quality.


Assuntos
Dislexia , Escrita Manual , Humanos , Criança , Dislexia/fisiopatologia , Masculino , Feminino
5.
Brain Res ; 1834: 148891, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38554796

RESUMO

The traditional models of reading development describe how language processing and word decoding contribute to reading comprehension and how impairments in word decoding, a defining feature of dyslexia, affect reading comprehension outcomes. However, these models do not include word and sentence reading (contextual reading) fluency, both of which engage executive functions, with notably decreased performance in children with dyslexia. In the current study, we compared cortical thickness and sulcal depth (CT/SD) in the cingulo-opercular (CO) executive functions brain network in children with dyslexia and typical readers and examined associations with word vs. contextual reading fluency. Overall, CT was lower in insular regions and higher in parietal and caudal anterior cingulate cortex regions in children with dyslexia. Children with dyslexia showed positive correlations between word reading fluency and CT/SD in insular regions, whereas no significant correlations were observed in typical readers. For sentence reading fluency, negative correlations with CT/SD were found in insular regions in children with dyslexia, while positive correlations with SD were found in insular regions in typical readers. These results demonstrate the differential relations between word and sentence reading fluency and anatomical circuitry supporting executive functions in children with dyslexia vs. typical readers. It also suggests that word and sentence reading fluency, relate to morphology of executive function-related regions in children with dyslexia, whereas in typical readers, only sentence reading fluency relates to morphology of executive function regions. The results also highlight the role of the insula within the CO network in reading fluency. Here we suggest that word and sentence reading fluency are distinct components of reading that should each be included in the Simple View of Reading traditional model.


Assuntos
Córtex Cerebral , Dislexia , Imageamento por Ressonância Magnética , Leitura , Humanos , Criança , Masculino , Feminino , Dislexia/fisiopatologia , Dislexia/diagnóstico por imagem , Dislexia/patologia , Imageamento por Ressonância Magnética/métodos , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Giro do Cíngulo/fisiopatologia , Giro do Cíngulo/diagnóstico por imagem , Giro do Cíngulo/patologia , Função Executiva/fisiologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Rede Nervosa/patologia , Mapeamento Encefálico/métodos
6.
J Neurodev Disord ; 15(1): 25, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37550628

RESUMO

BACKGROUND: Developmental dyslexia (DD) and attention deficit/hyperactivity disorder (ADHD) are highly comorbid neurodevelopmental disorders. Individuals with DD or ADHD have both been shown to have deficits in white matter tracts associated with reading and attentional control networks. However, white matter diffusivity in individuals comorbid with both DD and ADHD (DD + ADHD) has not been specifically explored. METHODS: Participants were 3rd and 4th graders (age range = 7 to 11 years; SD = 0.69) from three diagnostic groups ((DD (n = 40), DD + ADHD (n = 22), and typical developing (TD) (n = 20)). Behavioral measures of reading and attention alongside measures of white matter diffusivity were collected for all participants. RESULTS: DD + ADHD and TD groups differed in mean fractional anisotropy (FA) for the left and right Superior Longitudinal Fasciculus (SLF)-Parietal Terminations and SLF-Temporal Terminations. Mean FA for the DD group across these SLF tracts fell between the lower DD + ADHD and higher TD averages. No differences in mean diffusivity nor significant brain-behavior relations were found. CONCLUSIONS: Findings suggest that WM diffusivity in the SLF increases along a continuum across DD + ADHD, DD, and TD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Dislexia , Substância Branca , Substância Branca/fisiopatologia , Dislexia/complicações , Dislexia/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Análise de Variância , Atenção , Humanos , Criança , Leitura , Função Executiva
7.
Ann Dyslexia ; 73(2): 260-287, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36626093

RESUMO

This study had three goals: to examine the stability of deficits in the phonological and lexical routes in dyslexia (group study), to determine the prevalence of dyslexia profiles (multiple-case study), and to identify the prediction of phonemic segmentation and discrimination skills before reading acquisition on future reading level. Among a group of 373 non-readers seen at age 5, 38 students were subsequently diagnosed as either consistent dyslexic readers (18 DYS) or consistent typical readers (20 TR). Their phonological and lexical reading skills were assessed at ages 10 and 17 and their phonemic segmentation and discrimination skills at age 5. In comparison with TR of the same chronological age (CA-TR), individuals with dyslexia demonstrated an impairment of the two reading routes, especially of the phonological reading route. In the comparison with younger TR (age 10) of the same reading level (RL-TR), only a deficit of the phonological route is observed. In the multiple-case study, the comparisons with CA-TR showed a prevalence of mixed profiles and very few dissociated profiles, whereas the comparison with RL-TR resulted mostly in two profiles depending on the measure: a phonological profile when accuracy was used and a delayed profile when speed was used. In addition, the correlations between early phonemic segmentation and discrimination skills (age 5) and later reading skills (age 17) were significant, and in the group of individuals with dyslexia, early phonemic segmentation skills significantly predicted these later reading skills. Phonological reading deficits are persistent and mainly caused by early phonemic impairments.


Assuntos
Dislexia , Fonética , Leitura , Adolescente , Criança , Pré-Escolar , Humanos , Dislexia/classificação , Dislexia/diagnóstico , Dislexia/epidemiologia , Dislexia/fisiopatologia , Estudantes , Estudos de Casos e Controles , Prevalência , Estudos Longitudinais , França/etnologia , Inglaterra/etnologia , Envelhecimento
8.
J Neurosci ; 42(1): 121-134, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34782439

RESUMO

Children with and without dyslexia differ in their behavioral responses to visual information, particularly when required to pool dynamic signals over space and time. Importantly, multiple processes contribute to behavioral responses. Here we investigated which processing stages are affected in children with dyslexia when performing visual motion processing tasks, by combining two methods that are sensitive to the dynamic processes leading to responses. We used a diffusion model which decomposes response time and accuracy into distinct cognitive constructs, and high-density EEG. Fifty children with dyslexia (24 male) and 50 typically developing children (28 male) 6-14 years of age judged the direction of motion as quickly and accurately as possible in two global motion tasks (motion coherence and direction integration), which varied in their requirements for noise exclusion. Following our preregistered analyses, we fitted hierarchical Bayesian diffusion models to the data, blinded to group membership. Unblinding revealed reduced evidence accumulation in children with dyslexia compared with typical children for both tasks. Additionally, we identified a response-locked EEG component which was maximal over centro-parietal electrodes which indicated a neural correlate of reduced drift rate in dyslexia in the motion coherence task, thereby linking brain and behavior. We suggest that children with dyslexia tend to be slower to extract sensory evidence from global motion displays, regardless of whether noise exclusion is required, thus furthering our understanding of atypical perceptual decision-making processes in dyslexia.SIGNIFICANCE STATEMENT Reduced sensitivity to visual information has been reported in dyslexia, with a lively debate about whether these differences causally contribute to reading difficulties. In this large preregistered study with a blind modeling approach, we combine state-of-the art methods in both computational modeling and EEG analysis to pinpoint the stages of processing that are atypical in children with dyslexia in two visual motion tasks that vary in their requirement for noise exclusion. We find reduced evidence accumulation in children with dyslexia across both tasks, and identify a neural marker, allowing us to link brain and behavior. We show that children with dyslexia exhibit general difficulties with extracting sensory evidence from global motion displays, not just in tasks that require noise exclusion.


Assuntos
Encéfalo/fisiopatologia , Tomada de Decisões/fisiologia , Dislexia/fisiopatologia , Percepção de Movimento/fisiologia , Adolescente , Criança , Eletroencefalografia , Feminino , Humanos , Masculino
9.
J Neurosci ; 42(7): 1328-1342, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-34969869

RESUMO

A main characteristic of dyslexia is poor use of sound categories. We now studied within-session learning of new sound categories in dyslexia, behaviorally and neurally, using fMRI. Human participants (males and females) with and without dyslexia were asked to discriminate which of two serially-presented tones had a higher pitch. The task was administered in two protocols, with and without a repeated reference frequency. The reference condition introduces regularity, and enhances frequency sensitivity in typically developing (TD) individuals. Enhanced sensitivity facilitates the formation of "high" and "low" pitch categories above and below this reference, respectively. We found that in TDs, learning was paralleled by a gradual decrease in activation of the primary auditory cortex (PAC), and reduced activation of the superior temporal gyrus (STG) and left posterior parietal cortex (PPC), which are important for using sensory history. No such sensitivity was found among individuals with dyslexia (IDDs). Rather, IDDs showed reduced behavioral learning of stimulus regularities and no regularity-associated adaptation in the auditory cortex or in higher-level regions. We propose that IDDs' reduced cortical adaptation, associated with reduced behavioral learning of sound regularities, underlies their impoverished use of stimulus history, and consequently impedes their formation of rich sound categories.SIGNIFICANCE STATEMENT Reading difficulties in dyslexia are often attributed to poor use of phonological categories. To test whether poor category use could result from poor learning of new sound categories in general, we administered an auditory discrimination task that examined the learning of new pitch categories above and below a repeated reference sound. Individuals with dyslexia (IDDs) learned categories slower than typically developing (TD) individuals. TD individuals showed adaptation to the repeated sounds that paralleled the category learning in their primary auditory cortex (PAC) and other higher-level regions. In dyslexia, no brain region showed such adaptation. We suggest that poor learning of sound statistics in sensory regions may underlie the poor representations of both speech and nonspeech categories in dyslexia.


Assuntos
Adaptação Fisiológica/fisiologia , Córtex Auditivo/fisiopatologia , Dislexia/fisiopatologia , Aprendizagem/fisiologia , Percepção da Altura Sonora/fisiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Som , Percepção da Fala/fisiologia
10.
Curr Med Sci ; 41(6): 1239-1246, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34874487

RESUMO

OBJECTIVE: This study aimed to explore the orthographic processing of simplified Chinese characters in developmental dyslexic children in Kashgar, Xinjiang, China, and provide a theoretical basis for intervention strategies for developmental dyslexia in Chinese. METHODS: Using event-related potential (ERP) measures, 18 developmental dyslexic children and 23 typically developing children performed a character decision task with three types of stimuli: real characters (RCs), pseudocharacters (PCs), and noncharacters (NCs). RESULTS: Behavioral results showed that the control children displayed a faster and higher accurate performance than the dyslexic children across PCs and NCs. ERP data revealed that the RCs and PCs elicited a stronger P200 than the NCs. Compared with the RCs and NCs, children in the control group showed more N400 negatives for PCs. It is worth mentioning that dyslexic children did not show any difference on N400, which reflected the insufficient orthographic processing of dyslexic children in China. CONCLUSION: These results show that Chinese dyslexic children had orthographic processing defects.


Assuntos
Dislexia , Potenciais Evocados/fisiologia , Testes de Linguagem , Criança , China , Dislexia/fisiopatologia , Dislexia/psicologia , Eletroencefalografia , Feminino , Humanos , Masculino
11.
BMC Neurosci ; 22(1): 55, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34525977

RESUMO

BACKGROUND: It is important to improve verbal Working Memory (WM) in reading disability, as it is a key factor in learning. There are commercial verbal WM training programs, which have some short-term effects only on the verbal WM capacity, not reading. However, because of some weaknesses in current verbal WM training programs, researchers suggested designing and developing newly structured programs that particularly target educational functions such as reading skills. In the current double-blind randomized clinical trial study, we designed a new Verbal Working Memory-Balance (VWM-B) program which was carried out using a portable robotic device. The short-term effects of the VWM-B program, on verbal WM capacity, reading skills, and postural control were investigated in Iranian children with developmental dyslexia. RESULTS: The effectiveness of the VWM-B program was compared with the VWM-program as a traditional verbal WM training. In comparison with VWM-program, the participants who received training by the VWM-B program showed superior performance on verbal WM capacity, reading skills, and postural control after a short-term intervention. CONCLUSIONS: We proposed that the automatized postural control resulting from VWM-B training had a positive impact on improving verbal WM capacity and reading ability. Based on the critical role of the cerebellum in automatizing skills, our findings support the cerebellar deficit theory in dyslexia. TRIAL REGISTRATION: This trial was (retrospectively) registered on 8 February 2018 with the Iranian Registry of Clinical Trials (IRCT20171219037953N1).


Assuntos
Dislexia/fisiopatologia , Dislexia/terapia , Memória de Curto Prazo/fisiologia , Equilíbrio Postural/fisiologia , Robótica/métodos , Aprendizagem Verbal/fisiologia , Criança , Método Duplo-Cego , Dislexia/epidemiologia , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Masculino
12.
Nat Commun ; 12(1): 5439, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521851

RESUMO

Autism is a neurodevelopmental disorder characterized by impaired social skills, motor and perceptual atypicalities. These difficulties were explained within the Bayesian framework as either reflecting oversensitivity to prediction errors or - just the opposite - slow updating of such errors. To test these opposing theories, we administer paced finger-tapping, a synchronization task that requires use of recent sensory information for fast error-correction. We use computational modelling to disentangle the contributions of error-correction from that of noise in keeping temporal intervals, and in executing motor responses. To assess the specificity of tapping characteristics to autism, we compare performance to both neurotypical individuals and individuals with dyslexia. Only the autism group shows poor sensorimotor synchronization. Trial-by-trial modelling reveals typical noise levels in interval representations and motor responses. However, rate of error correction is reduced in autism, impeding synchronization ability. These results provide evidence for slow updating of internal representations in autism.


Assuntos
Transtorno Autístico/fisiopatologia , Imagem Corporal/psicologia , Dislexia/fisiopatologia , Transtornos Psicomotores/fisiopatologia , Desempenho Psicomotor , Transtorno Autístico/psicologia , Teorema de Bayes , Criança , Dislexia/psicologia , Feminino , Dedos , Humanos , Masculino , Modelos Estatísticos , Periodicidade , Testes Psicológicos
13.
Elife ; 102021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34569931

RESUMO

Brain abnormalities in the reading network have been repeatedly reported in individuals with developmental dyslexia (DD); however, it is still not totally understood where the structural and functional abnormalities are consistent/inconsistent across languages. In the current multimodal meta-analysis, we found convergent structural and functional alterations in the left superior temporal gyrus across languages, suggesting a neural signature of DD. We found greater reduction in grey matter volume and brain activation in the left inferior frontal gyrus in morpho-syllabic languages (e.g. Chinese) than in alphabetic languages, and greater reduction in brain activation in the left middle temporal gyrus and fusiform gyrus in alphabetic languages than in morpho-syllabic languages. These language differences are explained as consequences of being DD while learning a specific language. In addition, we also found brain regions that showed increased grey matter volume and brain activation, presumably suggesting compensations and brain regions that showed inconsistent alterations in brain structure and function. Our study provides important insights about the etiology of DD from a cross-linguistic perspective with considerations of consistency/inconsistency between structural and functional alterations.


Assuntos
Encéfalo/fisiopatologia , Dislexia/fisiopatologia , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Criança , Dislexia/diagnóstico por imagem , Feminino , Humanos , Idioma , Aprendizagem , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
14.
Clin Neurophysiol ; 132(11): 2798-2807, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34592558

RESUMO

OBJECTIVE: We combined electroencephalography (EEG) and eye-tracking recordings to examine the underlying factors elicited during the serial Rapid-Automatized Naming (RAN) task that may differentiate between children with dyslexia (DYS) and chronological age controls (CAC). METHODS: Thirty children with DYS and 30 CAC (Mage = 9.79 years; age range 7.6 through 12.1 years) performed a set of serial RAN tasks. We extracted fixation-related potentials (FRPs) under phonologically similar (rime-confound) or visually similar (resembling lowercase letters) and dissimilar (non-confounding and discrete uppercase letters, respectively) control tasks. RESULTS: Results revealed significant differences in FRP amplitudes between DYS and CAC groups under the phonologically similar and phonologically non-confounding conditions. No differences were observed in the case of the visual conditions. Moreover, regression analysis showed that the average amplitude of the extracted components significantly predicted RAN performance. CONCLUSION: FRPs capture neural components during the serial RAN task informative of differences between DYS and CAC and establish a relationship between neurocognitive processes during serial RAN and dyslexia. SIGNIFICANCE: We suggest our approach as a methodological model for the concurrent analysis of neurophysiological and eye-gaze data to decipher the role of RAN in reading.


Assuntos
Dislexia/fisiopatologia , Eletroencefalografia/métodos , Movimentos Oculares/fisiologia , Tecnologia de Rastreamento Ocular , Tempo de Reação/fisiologia , Leitura , Criança , Dislexia/diagnóstico , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos
15.
Clin Neurophysiol ; 132(10): 2384-2390, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34454265

RESUMO

OBJECTIVE: Developmental dyslexia is a reading disorder that features difficulties in perceiving and tracking rhythmic regularities in auditory streams, such as speech and music. Studies on typical healthy participants have shown that power fluctuations of neural oscillations in beta band (15-25 Hz) reflect an essential mechanism for tracking rhythm or entrainment and relate to predictive timing and attentional processes. Here we investigated whether adults with dyslexia have atypical beta power fluctuation. METHODS: The electroencephalographic activities of individuals with dyslexia (n = 13) and typical control participants (n = 13) were measured while they passively listened to an isochronous tone sequence (2 Hz presentation rate). The time-frequency neural activities generated from auditory cortices were analyzed. RESULTS: The phase of beta power fluctuation at the 2 Hz stimulus presentation rate differed and appeared opposite between individuals with dyslexia and controls. CONCLUSIONS: Atypical beta power fluctuation might reflect deficits in perceiving and tracking auditory rhythm in dyslexia. SIGNIFICANCE: These findings extend our understanding of atypical neural activities for tracking rhythm in dyslexia and could inspire novel methods to objectively measure the benefits of training, and predict potential benefit of auditory rhythmic rehabilitation programs on an individual basis.


Assuntos
Estimulação Acústica/métodos , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Ritmo beta/fisiologia , Dislexia/fisiopatologia , Adulto , Dislexia/diagnóstico , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Adulto Jovem
16.
Hum Brain Mapp ; 42(14): 4497-4509, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34197028

RESUMO

Primary education is the incubator for learning academic skills that help children to become a literate, communicative, and independent person. Over this learning period, nonlinear and regional changes in the brain occur, but how these changes relate to academic performance, such as reading ability, is still unclear. In the current study, we analyzed longitudinal T1 MRI data of 41 children in order to investigate typical cortical development during the early reading stage (end of kindergarten-end of grade 2) and advanced reading stage (end of grade 2-middle of grade 5), and to detect putative deviant trajectories in children with dyslexia. The structural brain change was quantified with a reliable measure that directly calculates the local morphological differences between brain images of two time points, while considering the global head growth. When applying this measure to investigate typical cortical development, we observed that left temporal and temporoparietal regions belonging to the reading network exhibited an increase during the early reading stage and stabilized during the advanced reading stage. This suggests that the natural plasticity window for reading is within the first years of primary school, hence earlier than the typical period for reading intervention. Concerning neurotrajectories in children with dyslexia compared to typical readers, we observed no differences in gray matter development of the left reading network, but we found different neurotrajectories in right IFG opercularis (during the early reading stage) and in right isthmus cingulate (during the advanced reading stage), which could reflect compensatory neural mechanisms.


Assuntos
Córtex Cerebral , Desenvolvimento Infantil , Dislexia , Rede Nervosa , Neuroimagem , Leitura , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/crescimento & desenvolvimento , Criança , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Dislexia/diagnóstico por imagem , Dislexia/patologia , Dislexia/fisiopatologia , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/anatomia & histologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/crescimento & desenvolvimento
17.
Hum Brain Mapp ; 42(14): 4580-4596, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34219304

RESUMO

The importance of (inherited) genetic impact in reading development is well established. De novo mutation is another important contributor that is recently gathering interest as a major liability of neurodevelopmental disorders, but has been neglected in reading research to date. Paternal age at childbirth (PatAGE) is known as the most prominent risk factor for de novo mutation, which has been repeatedly shown by molecular genetic studies. As one of the first efforts, we performed a preliminary investigation of the relationship between PatAGE, offspring's reading, and brain structure in a longitudinal neuroimaging study following 51 children from kindergarten through third grade. The results showed that greater PatAGE was significantly associated with worse reading, explaining an additional 9.5% of the variance after controlling for a number of confounds-including familial factors and cognitive-linguistic reading precursors. Moreover, this effect was mediated by volumetric maturation of the left posterior thalamus from ages 5 to 8. Complementary analyses indicated the PatAGE-related thalamic region was most likely located in the pulvinar nuclei and related to the dorsal attention network by using brain atlases, public datasets, and offspring's diffusion imaging data. Altogether, these findings provide novel insights into neurocognitive mechanisms underlying the PatAGE effect on reading acquisition during its earliest phase and suggest promising areas of future research.


Assuntos
Dislexia , Rede Nervosa , Idade Paterna , Leitura , Tálamo , Criança , Pré-Escolar , Estudos Transversais , Dislexia/diagnóstico por imagem , Dislexia/etiologia , Dislexia/patologia , Dislexia/fisiopatologia , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/anatomia & histologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/crescimento & desenvolvimento , Pulvinar/anatomia & histologia , Pulvinar/diagnóstico por imagem , Pulvinar/crescimento & desenvolvimento , Tálamo/anatomia & histologia , Tálamo/diagnóstico por imagem , Tálamo/crescimento & desenvolvimento
18.
Neuroimage ; 241: 118411, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34293464

RESUMO

Current views on the neural network subserving reading and its deficits in dyslexia rely largely on evidence derived from functional neuroimaging studies. However, understanding the structural organization of reading and its aberrations in dyslexia requires a hodological approach, studies of which have not provided consistent findings. Here, we adopted a whole brain hodological approach and investigated relationships between structural white matter connectivity and reading skills and phonological processing in a cross-sectional study of 44 adults using individual local connectome matrix from diffusion MRI data. Moreover, we performed quantitative anisotropy aided differential tractography to uncover structural white matter anomalies in dyslexia (23 dyslexics and 21 matched controls) and their correlation to reading-related skills. The connectometry analyses indicated that reading skills and phonological processing were both associated with corpus callosum (tapetum), forceps major and minor, as well as cerebellum bilaterally. Furthermore, the left dorsal and right thalamic pathways were associated with phonological processing. Differential tractography analyses revealed structural white matter anomalies in dyslexics in the left ventral route and bilaterally in the dorsal route compared to the controls. Connectivity deficits were also observed in the corpus callosum, forceps major, vertical occipital fasciculus and corticostriatal and thalamic pathways. Altered structural connectivity in the observed differential tractography results correlated with poor reading skills and phonological processing. Using a hodological approach, the current study provides novel evidence for the extent of the reading-related connectome and its aberrations in dyslexia. The results conform current functional neuroanatomical models of reading and developmental dyslexia but provide novel network-level and tract-level evidence on structural connectivity anomalies in dyslexia, including the vertical occipital fasciculus.


Assuntos
Conectoma/métodos , Dislexia/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Leitura , Substância Branca/diagnóstico por imagem , Adulto , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Estudos Transversais , Dislexia/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/fisiologia , Substância Branca/fisiologia , Adulto Jovem
19.
Medicine (Baltimore) ; 100(25): e26464, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34160450

RESUMO

ABSTRACT: Previous studies have identified inhibitory deficits in dyslexic children, but we have little understanding of their neural mechanisms, especially for Chinese children with developmental dyslexia.We used a double-blind controlled trial to study the electroencephalogram responses of dyslexic and non-dyslexic children when performing the Stroop color-word test.Behavioral data showed differences in response time and accuracy between the 2 groups. In the event-related potentials (ERP) results, dyslexic children displayed larger P2 and P3b on congruent trials, while non-dyslexic children displayed larger P2 and P3b on incongruent trials, the 2 groups showed opposite brain activation patterns on the Stroop test.Dyslexic children have poor inhibitory function, and this poor inhibition may be related to their abnormal brain activation patterns.


Assuntos
Encéfalo/fisiopatologia , Dislexia/fisiopatologia , Potenciais Evocados/fisiologia , Inibição Neural/fisiologia , Teste de Stroop , Estudos de Casos e Controles , Criança , Método Duplo-Cego , Dislexia/diagnóstico , Eletroencefalografia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia
20.
Hum Genet ; 140(8): 1183-1200, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34076780

RESUMO

Dyslexia is a common heritable developmental disorder involving impaired reading abilities. Its genetic underpinnings are thought to be complex and heterogeneous, involving common and rare genetic variation. Multigenerational families segregating apparent monogenic forms of language-related disorders can provide useful entrypoints into biological pathways. In the present study, we performed a genome-wide linkage scan in a three-generational family in which dyslexia affects 14 of its 30 members and seems to be transmitted with an autosomal dominant pattern of inheritance. We identified a locus on chromosome 7q21.11 which cosegregated with dyslexia status, with the exception of two cases of phenocopy (LOD = 2.83). Whole-genome sequencing of key individuals enabled the assessment of coding and noncoding variation in the family. Two rare single-nucleotide variants (rs144517871 and rs143835534) within the first intron of the SEMA3C gene cosegregated with the 7q21.11 risk haplotype. In silico characterization of these two variants predicted effects on gene regulation, which we functionally validated for rs144517871 in human cell lines using luciferase reporter assays. SEMA3C encodes a secreted protein that acts as a guidance cue in several processes, including cortical neuronal migration and cellular polarization. We hypothesize that these intronic variants could have a cis-regulatory effect on SEMA3C expression, making a contribution to dyslexia susceptibility in this family.


Assuntos
Dislexia/genética , Predisposição Genética para Doença , Padrões de Herança , Polimorfismo de Nucleotídeo Único , Semaforinas/genética , Sequência de Bases , Movimento Celular , Cromossomos Humanos Par 7 , Dislexia/diagnóstico por imagem , Dislexia/metabolismo , Dislexia/fisiopatologia , Família , Feminino , Expressão Gênica , Genes Dominantes , Ligação Genética , Loci Gênicos , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Íntrons , Escore Lod , Masculino , Neuroimagem , Neurônios/metabolismo , Neurônios/patologia , Linhagem , Fenótipo , Semaforinas/deficiência , Sequenciamento Completo do Genoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...