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1.
Neuropsychologia ; 193: 108763, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38141965

RESUMO

Despite reading being an essential and almost universal skill in the developed world, reading proficiency varies substantially from person to person. To study why, the fMRI field is beginning to turn from single-word or nonword reading tasks to naturalistic stimuli like connected text and listening to stories. To study reading development in children just beginning to read, listening to stories is an appropriate paradigm because speech perception and phonological processing are important for, and are predictors of, reading proficiency. Our study examined the relationship between behavioral reading-related skills and the neural response to listening to stories in the fMRI environment. Functional MRI were gathered in a 3T TIM-Trio scanner. During the fMRI scan, children aged approximately 7 years listened to professionally narrated common short stories and answered comprehension questions following the narration. Analyses of the data used inter-subject correlation (ISC), and representational similarity analysis (RSA). Our primary finding is that ISC reveals areas of increased synchrony in both high- and low-performing emergent readers previously implicated in reading ability/disability. Of particular interest are that several previously identified brain regions (medial temporal gyrus (MTG), inferior frontal gyrus (IFG), inferior temporal gyrus (ITG)) were found to "synchronize" across higher reading ability participants, while lower reading ability participants had idiosyncratic activation patterns in these regions. Additionally, two regions (superior frontal gyrus (SFG) and another portion of ITG) were recruited by all participants, but their specific timecourse of activation depended on reading performance. These analyses support the idea that different brain regions involved in reading follow different developmental trajectories that correlate with reading proficiency on a spectrum rather than the usual dichotomy of poor readers versus strong readers.


Assuntos
Dislexia , Deficiências da Aprendizagem , Criança , Humanos , Leitura , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Encéfalo/fisiologia
2.
PLoS One ; 18(12): e0292330, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38157354

RESUMO

One theory of the origins of reading disorders (i.e., dyslexia) is a language network which cannot effectively 'entrain' to speech, with cascading effects on the development of phonological skills. Low-gamma (low-γ, 30-45 Hz) neural activity, particularly in the left hemisphere, is thought to correspond to tracking at phonemic rates in speech. The main goals of the current study were to investigate temporal low-γ band-power during rest in a sample of children and adolescents with and without reading disorder (RD). Using a Bayesian statistical approach to analyze the power spectral density of EEG data, we examined whether (1) resting-state temporal low-γ power was attenuated in the left temporal region in RD; (2) low-γ power covaried with individual reading performance; (3) low-γ temporal lateralization was atypical in RD. Contrary to our expectations, results did not support the hypothesized effects of RD status and poor decoding ability on left hemisphere low-γ power or lateralization: post-hoc tests revealed that the lack of atypicality in the RD group was not due to the inclusion of those with comorbid attentional deficits. However, post-hoc tests also revealed a specific left-dominance for low-γ rhythms in children with reading deficits only, when participants with comorbid attentional deficits were excluded. We also observed an inverse relationship between decoding and left-lateralization in the controls, such that those with better decoding skills were less likely to show left-lateralization. We discuss these unexpected findings in the context of prior theoretical frameworks on temporal sampling. These results may reflect the importance of real-time language processing to evoke gamma rhythms in the phonemic range during childhood and adolescence.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Dislexia , Criança , Adolescente , Humanos , Teorema de Bayes , Ritmo Gama , Idioma
3.
Neuroimage ; 282: 120390, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37751811

RESUMO

Recent work using fMRI inter-subject correlation analysis has provided new information about the brain's response to video and audio narratives, particularly in frontal regions not typically activated by single words. This approach is very well suited to the study of reading, where narrative is central to natural experience. But since past reading paradigms have primarily presented single words or phrases, the influence of narrative on semantic processing in the brain - and how that influence might change with reading ability - remains largely unexplored. In this study, we presented coherent stories to adolescents and young adults with a wide range of reading abilities. The stories were presented in alternating visual and auditory blocks. We used a dimensional inter-subject correlation analysis to identify regions in which better and worse readers had varying levels of consistency with other readers. This analysis identified a widespread set of brain regions in which activity timecourses were more similar among better readers than among worse readers. These differences were not detected with standard block activation analyses. Worse readers had higher correlation with better readers than with other worse readers, suggesting that the worse readers had "idiosyncratic" responses rather than using a single compensatory mechanism. Close inspection confirmed that these differences were not explained by differences in IQ or motion. These results suggest an expansion of the current view of where and how reading ability is reflected in the brain, and in doing so, they establish inter-subject correlation as a sensitive tool for future studies of reading disorders.


Assuntos
Mapeamento Encefálico , Dislexia , Adolescente , Adulto Jovem , Humanos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Semântica , Cognição , Imageamento por Ressonância Magnética
4.
Front Hum Neurosci ; 17: 1195013, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37554411

RESUMO

Introduction: Executive functions (EFs) are linked to positive outcomes across the lifespan. Yet, methodological challenges have prevented precise understanding of the developmental trajectory of their organization. Methods: We introduce novel methods to address challenges for both measuring and modeling EFs using an accelerated longitudinal design with a large, diverse sample of students in middle childhood (N = 1,286; ages 8 to 14). We used eight adaptive assessments hypothesized to measure three EFs, working memory, context monitoring, and interference resolution. We deployed adaptive assessments to equate EF challenge across ages and a data-driven, network analytic approach to reveal the evolving diversity of EFs while simultaneously accounting for their unity. Results and discussion: Using this methodological paradigm shift brought new precision and clarity to the development of these EFs, showing these eight tasks are organized into three stable components by age 10, but refinement of composition of these components continues through at least age 14.

5.
Biling (Camb Engl) ; 26(2): 268-283, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37063520

RESUMO

Words' morphemic structure and their orthographic representations vary across languages. How do bilingual experiences with structurally distinct languages influence children's morphological processes for word reading? Focusing on English literacy in monolinguals and bilinguals (N = 350, ages 5-9), we first revealed unique contributions of derivational ( friend-li-est) and compound (girl-friend) morphology to early word reading. We then examined mechanisms of bilingual transfer in matched samples of Spanish-English and Chinese-English dual first language learners. Results revealed a principled cross-linguistic interaction between language group (Spanish vs. Chinese bilinguals) and type of morphological awareness. Specifically, bilinguals' proficiency with the type of morphology that was less characteristic of their home language explained greater variance in their English literacy. These findings showcase the powerful effects of bilingualism on word reading processes in children who have similar reading proficiency but different language experiences, thereby advancing theoretical perspectives on literacy across diverse learners.

6.
Sci Rep ; 13(1): 1947, 2023 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732569

RESUMO

Consequences of multilingualism vary from offering cognitive benefits to poor educational and cognitive outcomes. One aspect of multilingualism that has not been systematically examined is the typology of multilinguals' languages: Do differences and similarities between languages multilinguals are exposed to contribute to the development of their cognition and brain? We investigated n = 162 5-6-year-olds with various language backgrounds on a monolingual-to-quintilingual continuum. Our results show that typological linguistic diversity can be related to expressive vocabulary knowledge in the dominant language. On neural level, it relates to brain activation patterns in (among others) the PGa area in the bilateral IPL, a brain region previously associated with multilingual experience, but never with language typology. We propose an ecologically valid way of describing the continuum of multilingual language experience and provide evidence for both the cognition and the brain of multilingual kindergartners to be related to the typological linguistic diversity of their environment.


Assuntos
Multilinguismo , Idioma , Linguística , Encéfalo , Cognição/fisiologia
7.
J Learn Disabil ; 56(3): 193-209, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35499115

RESUMO

Exposure to stigma and stereotype threat is detrimental for numerous marginalized groups. Research has demonstrated that individuals with specific learning disabilities (SLDs) are vulnerable to stigmatization. The purpose of this systematic review was to summarize the studies investigating associations between SLD-related stigma and stereotype threat and psychological and academic outcomes in individuals with SLDs, as well as examine the overall effect size of these associations across studies. A total of 16 studies met inclusion criteria-12 studies (52 effect sizes) examined SLD stigma with psychological adjustment or academic outcomes, and six studies (eight effect sizes) examined SLD stereotype threat. Greater SLD stigma scores had a medium-sized and significant correlation with less self-esteem across nine effect sizes (r = -.39, p = .002). Other outcomes were not powered enough for meta-analyses, although studies generally showed that greater SLD stigma and stereotype threat was related to less optimal psychological adjustment. These results suggest that these negative experiences should be a target of intervention and support efforts for individuals with SLDs. The associations between SLD stigma and stereotype threat and academic performance outcomes were comparatively more heterogeneous and less robust. These findings highlight the need for more research on SLD-related stigma and stereotype threat.


Assuntos
Desempenho Acadêmico , Deficiências da Aprendizagem , Humanos , Estereotipagem , Estigma Social , Autoimagem
8.
Front Psychol ; 14: 1328523, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38250108

RESUMO

This scoping review provides an overview of previous empirical studies that used brain imaging techniques to investigate the neural correlates of emotional well-being (EWB). We compiled evidence on this topic into one accessible and usable document as a foundation for future research into the relationship between EWB and the brain. PRISMA 2020 guidelines were followed. We located relevant articles by searching five electronic databases with 95 studies meeting our inclusion criteria. We explored EWB measures, brain imaging modalities, research designs, populations studied, and approaches that are currently in use to characterize and understand EWB across the literature. Of the key concepts related to EWB, the vast majority of studies investigated positive affect and life satisfaction, followed by sense of meaning, goal pursuit, and quality of life. The majority of studies used functional MRI, followed by EEG and event-related potential-based EEG to study the neural basis of EWB (predominantly experienced affect, affective perception, reward, and emotion regulation). It is notable that positive affect and life satisfaction have been studied significantly more often than the other three aspects of EWB (i.e., sense of meaning, goal pursuit, and quality of life). Our findings suggest that future studies should investigate EWB in more diverse samples, especially in children, individuals with clinical disorders, and individuals from various geographic locations. Future directions and theoretical implications are discussed, including the need for more longitudinal studies with ecologically valid measures that incorporate multi-level approaches allowing researchers to better investigate and evaluate the relationships among behavioral, environmental, and neural factors. Systematic review registration: https://osf.io/t9cf6/.

9.
Front Hum Neurosci ; 17: 1294941, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38234592

RESUMO

Much progress has been made in research on the causal mechanisms of developmental dyslexia. In recent years, the "temporal sampling" account of dyslexia has evolved considerably, with contributions from neurogenetics and novel imaging methods resulting in a much more complex etiological view of the disorder. The original temporal sampling framework implicates disrupted neural entrainment to speech as a causal factor for atypical phonological representations. Yet, empirical findings have not provided clear evidence of a low-level etiology for this endophenotype. In contrast, the neural noise hypothesis presents a theoretical view of the manifestation of dyslexia from the level of genes to behavior. However, its relative novelty (published in 2017) means that empirical research focused on specific predictions is sparse. The current paper reviews dyslexia research using a dual framework from the temporal sampling and neural noise hypotheses and discusses the complementary nature of these two views of dyslexia. We present an argument for an integrated model of sensory temporal sampling as an etiological pathway for dyslexia. Finally, we conclude with a brief discussion of outstanding questions.

10.
Front Psychol ; 13: 1001555, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36533015

RESUMO

Introduction: The COVID-19 pandemic led to school closure and loss of in-person instruction during the 2019-2020 academic year across the United States, which had a profound impact on the reading development of beginning readers. In this study we tested if a research-informed educational technology (EdTech) program-GraphoLearn-could help alleviate the COVID-19 slide. We also sought to understand the profiles of children who benefitted most from this EdTech program. Methods: We tested participants' (N = 172 K-2 children) early literacy skills using a standardized measure (STAR) before and after playing GraphoLearn, and used the pre to post difference as the dependent variable. We first compared children's STAR actual and expected growth. Then we conducted a multiple regression analysis with data about engagement with GraphoLearn included as predictors. Additional predictors were extracted from GraphoLearn performance at study onset to assess children's letter-sound knowledge, rime awareness, and word recognition. Results: The difference between actual average reading growth and expected growth in a regular school year was not statistically significant. This suggests that children in our sample seem to be gaining reading skills as expected in a regular school year. Our multiple linear regression model (which accounted for R2 = 48% of reading growth) showed that older children, with higher baseline GraphoLearn word recognition, who played more units in a fixed number of days, made significantly more early literacy progress. Discussion: While lacking a control group, our preliminary results suggest that an EdTech program such as GraphoLearn may be a useful reading instructional tool during school shutdowns. In addition, our results suggest that practice with GraphoLearn was more effective and efficient when foundational instruction was already in place.

11.
Eur J Neurosci ; 55(3): 806-826, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35032071

RESUMO

Effortless print-sound integration is essential to reading development, and the superior temporal cortex (STC) is the most critical brain region. However, to date, the conclusion is almost restricted to alphabetic orthographies. To examine the neural basis in non-alphabetic languages and its relationship with reading abilities, we conducted a functional magnetic resonance imaging study in typically developing Chinese children. Two neuroimaging-based indicators of audiovisual processing-additive enhancement (higher activation in the congruent than the average activation of unimodal conditions) and neural integration (different activations between the congruent versus incongruent conditions)-were used to investigate character-sounds (opaque) and pinyin-sounds (transparent) processing. We found additive enhancement in bilateral STCs processing both character and pinyin stimulations. Moreover, the neural integrations in the left STC for the two scripts were strongly correlated. In terms of differentiation, first, areas beyond the STCs also showed additive enhancement in processing pinyin-sounds. Second, while the bilateral STCs, left inferior/middle frontal and parietal regions manifested a striking neural integration (incongruent > congruent) for character-sounds, no significant clusters were revealed for pinyin-sounds. Finally, the neural integration in the left middle frontal gyrus for characters was specifically associated with silent reading comprehension proficiency, indicating automatic semantic processing during implicit character-sound integration. In contrast, the neural integration in the left STC for pinyin was specifically associated with oral reading fluency that relies on grapho-phonological mapping. To summarize, this study revealed both script-universal and script-specific neurofunctional substrates of print-sound integration as well as their processing- and region-dependent associations with reading abilities in typical Chinese children.


Assuntos
Idioma , Fonética , Encéfalo/fisiologia , Mapeamento Encefálico , Criança , China , Humanos , Imageamento por Ressonância Magnética/métodos , Leitura
13.
J Learn Disabil ; 55(5): 427-442, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34628989

RESUMO

Several crucial reasons exist to determine whether an adult has had a reading disorder (RD) and to predict a child's likelihood of developing RD. The Adult Reading History Questionnaire (ARHQ) is among the most commonly used self-reported questionnaires. High ARHQ scores indicate an increased likelihood that an adult had RD as a child and that their children may develop RD. This study focused on whether a subset of ARHQ items (ARHQ-Brief) could be equally effective in assessing adults' reading history as the full ARHQ. We used a machine learning approach, lasso (known as L1 regularization), and identified 6 of 23 items that resulted in the ARHQ-Brief. Data from 97 adults and 47 children were included. With the ARHQ-Brief, we report a threshold of 0.323 as suitable to identify past likelihood of RD in adults with a sensitivity of 72.4% and a specificity of 81.5%. Comparison of predictive performances between ARHQ-Brief and the full ARHQ showed that ARHQ-Brief explained an additional 10%-35.2% of the variance in adult and child reading. Furthermore, we validated ARHQ-Brief's superior ability to predict reading ability using an independent sample of 28 children. We close by discussing limitations and future directions.


Assuntos
Dislexia , Adulto , Criança , Cognição , Dislexia/diagnóstico , Dislexia/epidemiologia , Humanos , Aprendizado de Máquina , Inquéritos e Questionários
14.
Ann Dyslexia ; 72(1): 1-27, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34324164

RESUMO

Prior studies have suggested that grit and resilience predict both academic and career success. However, these qualities have not been examined in children with reading disorder (RD). We therefore investigated whether grit and resilience were associated with anxiety, depression, academic performance, and quality of life (QOL) in these students. This 3-year longitudinal cohort study included 163 participants with RD from 3 schools. Evaluations were completed by parents and/or teachers every 3 months. The Grit and Resilience Scale was adapted from the 10-item Connor-Davidson Resilience Scale and the 12-item Grit Scale. Outcome measures included anxiety (School Anxiety Scale - Teacher Report and the 8-item Spence Children's Anxiety Scale), depression (Short Mood and Feelings Questionnaire), academic performance, and QOL (Pediatric QOL Inventory 4.0). Multivariate linear regression models (adjusting for age and sex) assessed the associations at baseline. Repeated measures analysis using mixed-effects models assessed the relationship longitudinally. There were statistically significant associations between grit and resilience and all outcomes at baseline and over time. After adjusting for age and sex, improved grit and resilience was associated with decreased anxiety (ß = - 0.4, p < 0.001) and improved academic performance (ß = 0.5, p < 0.001) when grit and resilience was measured by teachers, as well as decreased depression (ß = - 0.3, p < 0.001) and improved QOL (ß = 0.6, p < 0.001) when grit and resilience was measured by parents. Grit and resilience are significantly related to mental health, academic performance, and QOL in children with RD. This suggests that interventions to improve grit and resilience may lead to positive benefits.


Assuntos
Dislexia , Qualidade de Vida , Criança , Estudos de Coortes , Humanos , Estudos Longitudinais , Leitura
15.
J Res Read ; 45(3): 367-384, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36970562

RESUMO

Educational neuroscience approaches have helped to elucidate the brain basis of Reading Disability (RD) and of reading intervention response; however, there is often limited translation of this knowledge to the broader scientific and educational communities. Moreover, this work is traditionally lab-based, and thus the underlying theories and research questions are siloed from classroom practices. With growing awareness of the neurobiological origins of RD and increasing popularity of putative "brain-based" approaches in clinics and classrooms, it is imperative that we create more direct and bidirectional communication between scientists and practitioners. Such direct collaborations can help dispel neuromyths, and lead to increased understanding of the promises and pitfalls of neuroscience approaches. Moreover, direct partnerships between researchers and practitioners can lead to greater ecological validity in study designs to improve upon the translational potential of findings. To this end, we have forged collaborative partnerships, and built cognitive neuroscience laboratories within independent reading disabilities schools. This approach affords frequent and ecologically valid neurobiological assessment as children's reading improves in response to intervention. It also permits the creation of dynamic models of leading and lagging relationships of students' learning, and identification of individual-level predictors of intervention response. The partnerships also provide in-depth knowledge of student characteristics and classroom practices, which, when combined with the data we acquire, may facilitate optimization of instructional approaches. In this commentary, we discuss the creation of our partnerships, the scientific problem we are addressing (variable response to reading intervention), and the epistemological significance of researcher-practitioner bi-directional learning.

16.
Front Psychol ; 12: 687651, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34733197

RESUMO

Perception of low-level auditory cues such as frequency modulation (FM) and rise time (RT) is crucial for development of phonemic representations, segmentation of word boundaries, and attunement to prosodic patterns in language. While learning an additional language, children may develop an increased sensitivity to these cues to extract relevant information from multiple types of linguistic input. Performance on these auditory processing tasks such as FM and RT by children learning another language is, however, unknown. Here we examine 92 English-speaking 7-8-year-olds in the U.S. and their performance in FM and RT perceptual tasks at the end of their second year in Cantonese or Spanish dual-language immersion compared to children in general English education programs. Results demonstrate that children in immersion programs have greater sensitivity to FM, but not RT, controlling for various factors. The immersion program students were also observed to have better phonological awareness performance. However, individual differences in FM sensitivity were not associated with phonological awareness, a pattern typically observed in monolinguals. These preliminary findings suggest a possible impact of formal language immersion on low-level auditory processing. Additional research is warranted to understand causal relationships and ultimate impact on language skills in multilinguals.

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.
Cortex ; 141: 262-279, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34102410

RESUMO

Numerous studies have consistently reported functional activation of the cerebellum during reading tasks, especially in the right cerebellar hemisphere. However, it remains unclear whether this region is also involved in reading during the earliest stages of reading acquisition. Here, we investigated whether and how the cerebellum contributes to reading acquisition. We tested 80 5-6-year-old kindergarteners, who performed a visual word matching task during which functional MRI (fMRI) data were collected. We found that bilateral cerebellar hemispheres were significantly activated during visual word processing. Moreover, activation of left cerebellar lobule VII extending to lobule VIII negatively and significantly correlated with current reading ability, whereas activation of right cerebellar lobule VII extending to lobule VIII significantly and positively correlated with future reading ability. Functional decoding via functional connectivity patterns further revealed that left and right cerebellar lobules connected with different cerebral cortex regions. Our results suggest a division of labor between the left and right cerebellar lobules in beginning readers.


Assuntos
Mapeamento Encefálico , Leitura , Cerebelo/diagnóstico por imagem , Criança , Pré-Escolar , Cognição , Humanos , Imageamento por Ressonância Magnética
19.
J Neuroimaging ; 31(5): 962-972, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34115429

RESUMO

BACKGROUND AND PURPOSE: The ventral occipitotemporal cortex (vOT) is a region crucial for reading acquisition through selective tuning to printed words. Developmental dyslexia is a disorder of reading with underlying neurobiological bases often associated with atypical neural responses to printed words. Previous studies have discovered anomalous structural development and function of the vOT in individuals with dyslexia. However, it remains unclear if or how structural abnormalities relate to functional alterations. METHODS: In this study, we acquired structural, functional (words and faces processing), and diffusion MRI data from 26 children with dyslexia (average age = 10.4 ± 2.0 years) and 14 age-matched typically developing readers (average age = 10.4 ± 1.6 years). Morphological indices of local gyrification, neurite density (i.e., dendritic arborization structure), and orientation dispersion (i.e., dendritic arborization orientation) were analyzed within the vOT region that showed preferential activation in typically developing readers for words (as compared to face stimuli). RESULTS: The two cohorts diverged significantly in both functional and structural measures. Compared to typically developing controls, children with dyslexia did not show selectivity for words in the left vOT (contrast: words > false fonts). This lack of tuning to printed words was associated with greater neurite dispersion heterogeneity in the dyslexia cohort, but similar neurite density. These group differences were not present in the homologous contralateral area, the right vOT. CONCLUSIONS: Our findings provide new insight into the neurobiology of the lack of vOT word tuning in dyslexia by linking behavior, alterations in functional activation, and neurite organization.


Assuntos
Dislexia , Imageamento por Ressonância Magnética , Mapeamento Encefálico , Córtex Cerebral , Criança , Dislexia/diagnóstico por imagem , Humanos , Leitura
20.
J Clin Exp Neuropsychol ; 43(3): 276-289, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33960276

RESUMO

Specific reading disability (SRD) is defined by genetic and neural risk factors that are not fully understood. The current study used imaging genetics methodology to investigate relationships between SEMA6D, brain structure, and reading. SEMA6D, located on SRD risk locus DYX1, is involved in axon guidance, synapse formation, and dendrite development. SEMA6D's associations with brain structure in reading-related regions of interest (ROIs) were investigated in a sample of children with a range of reading performance, from sites in Connecticut, CT (n = 67, 6-13 years, mean age = 9.07) and San Francisco, SF (n = 28, 5-8 years, mean age = 6.5). Multiple regression analyses revealed significant associations between SEMA6D's rs16959669 and cortical thickness in the fusiform gyrus and rs4270119 and gyrification in the supramarginal gyrus in the CT sample, but this was not replicated in the SF sample. Significant clusters were not associated with reading. For white matter volume, combined analyses across both samples revealed associations between reading and the left transverse temporal gyrus, left pars triangularis, left cerebellum, and right cerebellum. White matter volume in the left transverse temporal gyrus was nominally related to rs1817178, rs12050859, and rs1898110 in SEMA6D, and rs1817178 was significantly related to reading. Haplotype analyses revealed significant associations between the whole gene and brain phenotypes. Results suggest SEMA6D likely has an impact on multiple reading-related neural structures, but only white matter volume in the transverse temporal gyrus was significantly related to reading in the current sample. As the sample was young, the transverse temporal gyrus, involved in auditory perception, may be more strongly involved in reading because phonological processing is still being learned. The relationship between SEMA6D and reading may change as different brain regions are involved during reading development. Future research should examine mediating effects, use additional brain measures, and use an older sample to better understand effects.


Assuntos
Dislexia , Substância Branca , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Criança , Humanos , Imageamento por Ressonância Magnética , Neuroimagem , Lobo Parietal , Substância Branca/diagnóstico por imagem
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