RESUMEN
PURPOSE: Investigate if speech perception skills can differentiate school children with Specific Reading Disorders (SRD) with and without Persistent Speech Sound Disorders (PSSD). METHODS: 80 children, regularly enrolled in the 2nd (N=1), 3rd (N=28), 4th (N=29), 5th (N=15) and 6th (N=7) grades participated in the study. Control Group (CG) (N=48): no complaints, no speech alteration; and Resarch Group (RG) (N=32) - with SRD, RGI (N=15) without PSSD and RGII (N=17) with PSSD. Two tests evaluated auditory input reception: Simplified evaluation of auditory processing; and Perception task of nonwords, with Portuguese language structure (DNPLS). Data was analyzed by: Likelihood Ratio Test, Kruskal-Wallis test, Dunn test with Bonferroni correction, Mann-Whitney test, Spearman correlation, and construction of a ROC curve to obtain a threshold value for the correct answers in the perception of non-words test. RESULTS: Control and RGI showed higher correct answer scores than RGII. There was no difference between the correct answer distributions of the Control and RGI, and RGI and RGII in the test of DNPLS and the number of correct answers in the CG was higher than in the RGII. CONCLUSION: The ability to discriminate non-words enabled the differentiated between school-aged children with SRD associated with PSSD and typical children, thus characterizing this group for presenting a number of correct answers lower than 30.5, considering the task proposed to discriminate non-words. These results suggest that the presence of PSSD worsens the performance in speech perception of the schoolchildren with SRD.
OBJETIVO: Investigar se a habilidade de percepção de fala pode diferenciar escolares com Transtorno específico de aprendizagem (TAp) com e sem Transtorno Persistente dos Sons da Fala (TPSF). MÉTODO: Participaram da pesquisa 80 crianças, regularmente matriculadas no 2º (N=1), 3º (N=28), 4º (N=29), 5º (N=15), e 6º (N=7) anos, assim reunidos: Grupo Controle (N= 48) - sem queixas, sem alteração de fala; e Grupos Pesquisa (N = 32) - com TAp, sendo GPI (N = 15) sem TPSF e, GPII (N = 17), com TPSF. Duas provas avaliaram input auditivo: Avaliação simplificada do processamento auditivo; e Tarefa de percepção de pseudopalavras com estrutura da língua portuguesa - TDP. Os dados foram analisados pelos testes: Razão de Verossimilhanças, Kruskal-Wallis, Dunn com correção de Bonferroni, Mann-Whitney, correlação de Spearman, além da construção de uma curva ROC para obter um valor de corte para o número de acertos na prova de percepção de não palavras. RESULTADOS: Controle e GPI mostraram maiores escores de acerto que GPII. Não houve diferença entre as distribuições de acertos do Controle e GPI e do GPI e GPII na TDP e o número de acertos do GC foi maior que o do GPII. CONCLUSÃO: A habilidade de discriminação de pseudopalavras diferenciou os escolares com TAp e TPSF das crianças sem TPSF, caracterizando, assim esse grupo por apresentar número de acertos menor que 30,5, considerada a tarefa proposta para discriminar pseudopalavras. Esses resultados sugerem que a presença do TPSF piorou o desempenho em percepção de fala dos escolares com TAp.
Asunto(s)
Percepción del Habla , Trastorno Fonológico , Humanos , Percepción del Habla/fisiología , Niño , Trastorno Fonológico/fisiopatología , Trastorno Fonológico/diagnóstico , Masculino , Femenino , Estudios de Casos y Controles , Trastorno Específico de Aprendizaje/fisiopatología , Dislexia/fisiopatología , Dislexia/diagnósticoRESUMEN
INSTRUCTION: Children with a Specific Learning Disorder (SLD) write linguistic material more slowly than children with typically developing (TD). However, it is not known whether the same difficulties are present when they write numbers. The goal of the present study was to fill this gap and to compare TD's and SLD's speed in writing numbers both in words and in digits. METHODS: Therefore, we examined the ability to write numbers in words and digits (numerals) in a sample of sixth- to eighth-grade children diagnosed with SLD. We assessed 32 children with SLD (17 males and 15 females) and a control group of students with TD matched for sex, age, and grade with two writing speed tasks: writing numbers in words and in digits. The two tasks were administered both in normal condition (N) and in articulatory suppression condition (AS). RESULTS: We found that 6th to 8th graders with a SLD were slower than TD children when writing numbers, both in words and in digits, and their slowness was similar in the two cases. However, when the tasks were carried out under a condition of articulatory suppression, the SLD group exhibited a conspicuous impairment, only when writing numbers in words. A similar pattern of performance was observed also in the case of writing errors. CONCLUSION: We concluded that children with SLD have a general speed problem that may affect writing of different materials but also a specific problem related to the processing of phonological information during writing.
Asunto(s)
Trastorno Específico de Aprendizaje , Escritura , Humanos , Masculino , Femenino , Niño , Trastorno Específico de Aprendizaje/fisiopatología , Adolescente , Pruebas Neuropsicológicas , MatemáticaRESUMEN
Sex chromosome aneuploidies (SCA) are associated with an increased risk for specific learning disorders (SLD). Individuals with Klinefelter Syndrome (KS) show an increased incidence of developmental dyslexia and individuals with Turner Syndrome (TS) are often affected by developmental dyscalculia. Accordingly, KS frequently coincides with verbal deficits, and TS with visual-spatial impairments. Though neurocognitive profiles of KS and TS are well-established, little is known about the neurobiology underling learning in SCA. This review summarizes current structural and functional magnetic resonance imaging (MRI) studies in KS and TS related to literacy and mathematical skills. It includes studies that focus on correlates between brain anatomy and cognition in SCA and on functional brain responses during learning-related tasks and at rest. We highlight important neural circuits that are related to domain-specific skills of literacy and mathematics. We discuss how identifying neuroendophenotypes of learning in SCA might contribute to developing a novel framework for SLD that accounts for potential genetic effects on learning, and from the X and Y chromosomes specifically. Future research directions are considered to establish clear brain-behavior relationships that might ultimately improve the treatment of SLD in SCA across development.
Asunto(s)
Síndrome de Klinefelter/diagnóstico por imagen , Aberraciones Cromosómicas Sexuales , Trastorno Específico de Aprendizaje/diagnóstico por imagen , Síndrome de Turner/diagnóstico por imagen , Aneuploidia , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Femenino , Humanos , Síndrome de Klinefelter/genética , Síndrome de Klinefelter/fisiopatología , Alfabetización/psicología , Imagen por Resonancia Magnética , Masculino , Matemática , Cromosomas Sexuales/genética , Trastorno Específico de Aprendizaje/genética , Trastorno Específico de Aprendizaje/fisiopatología , Síndrome de Turner/genética , Síndrome de Turner/fisiopatologíaRESUMEN
BACKGROUND: Children with specific learning disabilities (SLD) have been observed to face participation restrictions in their daily life. AIMS: This study aims to examine the participation and environmental features of children with SLD compared to non-disabled children. METHODS AND PROCEDURES: This study was designed as a case-controlled study. Parents of children between 5 and 17 years of age with SLD (n = 90) and those who are non-disabled (n = 88) were included in this study to do the Participation and Environment Measure for Children and Youth (PEM-CY). RESULTS: Differences between groups were found statistically significant in home, school, and community settings between both participation and environmental features (p < 0.05). Children with SLD participated less frequently in school settings and were less involved in activities in home and school settings. Parents of children with SLD desired more change in their child's participation in all settings. Environmental factors were significantly more likely to be identified as barriers in the participation of children with SLD. CONCLUSION AND IMPLICATIONS: This study provides information about participation patterns and environmental factors for many children with SLD. The results provide insights into a rehabilitation program that may improve the participation of children with SLD, and on where greater efforts are needed to support participation and environmental features for children with SLD.
Asunto(s)
Actividades Cotidianas , Ambiente , Actividades Recreativas , Instituciones Académicas , Autocuidado , Trastorno Específico de Aprendizaje/fisiopatología , Adolescente , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , PadresRESUMEN
Rumination, namely a cognitive process characterized by a repetitive thinking focused on negative feelings and thoughts, is a significant predictor for the onset of internalizing symptoms and has also been found to run in families. Rumination has never been studied in children with specific learning disorders (SLD), a population that, due to its condition, might encounter more difficulties in daily life and is at risk of increased psychological distress, compared to typically developing (TD) peers. The present study covers this gap by examining whether children with SLD, and their parents, tend to use rumination more than TD peers and their parents. The study also explores associations between rumination and both children's and parents' emotional profile. Results on 25 children with SLD and 25 TD peers and their parents (n = 150), showed higher levels of rumination in children with SLD when referring to a negative social situation, as well as higher levels of rumination in both mothers and fathers of children with SLD. Modest correlations between parents' and children's rumination traits were also found. This study offers evidence on rumination as a possible risk factor for children with SLD, particularly considering when they deal with social contexts.
Asunto(s)
Conducta Infantil/psicología , Emociones , Relaciones Padres-Hijo , Padres/psicología , Trastorno Específico de Aprendizaje/fisiopatología , Trastorno Específico de Aprendizaje/psicología , Adulto , Niño , Femenino , Humanos , Italia , MasculinoRESUMEN
BACKGROUND: Previous research results suggest that ADHD symptoms explain the relationship between specific learning disability and externalising psychopathology and between math disability and anxiety, but not between reading disability and anxiety. For depression, previous results are mixed. AIMS: The current study aims to clarify this role of ADHD symptoms in the relationship between various areas of academic achievement (reading, writing, and math skills) and psychopathological symptoms (anxiety, depression, and conduct disorder). METHODS AND PROCEDURES: We used linear regressions based on data from a general population sample (N = 3014) collected using online assessment of 3rd and 4th grade students in Germany, which included measures of academic achievement and parent-reported psychopathological symptoms. OUTCOMES AND RESULTS: ADHD symptoms completely account for the relationship between reading/writing achievement and anxiety and between writing/math achievement and conduct problems. The negative relationship between academic achievement and depression was strongest for children with average or high ADHD symptom scores. CONCLUSIONS AND IMPLICATIONS: ADHD symptoms play an important role in explaining the relationship between academic achievement and psychopathological symptoms in elementary school children. The nature and size of this role depend on the exact constructs under study. We discuss implications for the support of children with learning problems, ADHD, and/or psychopathological problems.
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Rendimiento Académico , Ansiedad/psicología , Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Trastorno de la Conducta/psicología , Depresión/psicología , Trastorno Específico de Aprendizaje/fisiopatología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Niño , Femenino , Humanos , Masculino , Matemática , Lectura , Trastorno Específico de Aprendizaje/psicología , EscrituraRESUMEN
INTRODUCTION: Currently, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has new criteria that include a diagnostic reference to neurodevelopmental disorders. Neurodevelopmental disorders are diverse, and even though they are independent diagnostic entities they share common manifestations in people with brain damage or dysfunction of the prefrontal cortex; that is, neurodevelopmental disorders present different alterations in executive functions. DEVELOPMENT: The aim of the present study was to offer an overview of the recent findings on executive functioning in children, adolescents and young adults with different neurodevelopmental disorders: autistic spectrum disorder, attention-deficit/hyperactivity disorder and specific learning disorder. Hence, with this objective, 27 studies from the literature were reviewed. The results indicate a statistically significant association between the dimension of flexibility and attention deficit/hyperactivity disorder (W of Wilcoxon = 123.0; p = 0.011), and flexibility with autistic spectrum disorder (W of Wilcoxon = 101.5; p = 0.003); and absence of a statistically significant association between the different assessed dimensions and specific learning disorder. CONCLUSIONS: The dimensions of executive functioning are affected to a variable degree in different neurodevelopmental disorders. We can hypothesis that the dimensions that are affected in the different neurodevelopmental disorders can be characterized in terms of the existence of a continuum, and occasionally those dimensions are too complex to establish categorical limits when comparing different neurodevelopmental disorders.
TITLE: Déficits ejecutivos y trastornos del neurodesarrollo en la infancia y en la adolescencia.Introducción. Actualmente, en el Manual diagnóstico y estadístico de los trastornos mentales (DSM-5) se incluye una nueva categoría diagnóstica referida a trastornos del neurodesarrollo. Son diversos los trastornos del neurodesarrollo que, aun siendo entidades diagnósticas independientes, comparten manifestaciones comunes a las que presentan personas con daño cerebral o disfunción en la corteza prefrontal, es decir, presentan diferentes alteraciones de las funciones ejecutivas. Desarrollo. El propósito de este estudio es ofrecer una visión de los hallazgos actuales sobre el funcionamiento ejecutivo en niños y jóvenes con diferentes trastornos del neurodesarrollo: trastorno del espectro autista, trastorno por déficit de atención/hiperactividad y trastorno específico del aprendizaje. Con este objetivo se revisaron 27 artículos. Los resultados de los análisis indican una asociación estadísticamente significativa entre dimensión de flexibilidad y trastorno por déficit de atención/hiperactividad (W de Wilcoxon = 123; p = 0,011) y dimensión de flexibilidad y trastorno del espectro autista (W de Wilcoxon = 101,5; p = 0,003), y ausencia de asociación estadísticamente significativa entre las diferentes dimensiones evaluadas y trastorno específico del aprendizaje. Conclusiones. Las dimensiones ejecutivas se encuentran afectadas en los diferentes trastornos del neurodesarrollo en grado variable. Podemos hipotetizar la existencia de un continuo en las dimensiones que se encuentran afectadas en los diferentes trastornos del neurodesarrollo; en ocasiones, es complejo establecer límites categoriales cuando se comparan distintos trastornos.
Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/fisiopatología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Trastorno del Espectro Autista/fisiopatología , Trastorno del Espectro Autista/psicología , Función Ejecutiva , Trastorno Específico de Aprendizaje/fisiopatología , Trastorno Específico de Aprendizaje/psicología , HumanosRESUMEN
BACKGROUND: Very preterm (VPT) children showed delays in reading, spelling and maths, but their academic achievement profile is not clearly understood. AIMS: VPT children were compared with children with specific learning disorders (SLD) and typically developing (TD) children on academic achievement, considering cognitive and linguistic phenotypic markers. A learning profile analysis was also performed. METHODS: We included 170 10-year old monolingual Italian-speaking children (37 VPT, 28 SLD, 105 TD) assessing cognitive, linguistic and academic skills. RESULTS: On academic achievements VPT children fell behind TD peers in some reading (text speed, comprehension), spelling (non-word), and math (number knowledge, written calculations and problem-solving) tasks. SLD children underperformed in all academic tasks with respect to VPT and TD peers. Concerning cognitive and linguistic phenotypic markers, compared to TD peers, VPT children showed lower scores in verbal IQ and phonological fluency, SLD children in phonological processing and rapid automatized naming. VPT children showed a higher rate of at-risk performance in reading compared to TD group, but a minor percentage of impaired profiles and comorbidity among learning areas compared to SLD group. CONCLUSIONS AND IMPLICATIONS: The academic achievement profile of VPT children shows persistent delays, but it differs to that of SLD children, since delays are less widespread and severe, and differences were found in phenotypic markers and comorbidity. Follow-up programs and effective interventions are needed for VPT children.
Asunto(s)
Éxito Académico , Cognición , Discapacidades del Desarrollo/fisiopatología , Lenguaje , Matemática , Lectura , Trastorno Específico de Aprendizaje/fisiopatología , Escritura , Niño , Femenino , Humanos , Recien Nacido Extremadamente Prematuro , Recien Nacido Prematuro , Masculino , FenotipoRESUMEN
Children with specific learning disorders (SLDs) face a unique set of socio-emotional challenges as a result of their academic difficulties. Although a higher prevalence of anxiety in children with SLD is often reported, there is currently no research on cognitive mechanisms underlying this anxiety. One way to elucidate these mechanisms is to investigate attentional bias to threatening stimuli using a dot-probe paradigm. Our study compared children ages 9-16 with SLD (n = 48) to typically-developing (TD) controls (n = 33) on their attentional biases to stimuli related to general threats, reading, and stereotypes of SLD. We found a significant threat bias away from reading-related stimuli in the SLD, but not TD group. This attentional bias was not observed with the general threat and stereotype stimuli. Further, children with SLD reported greater anxiety compared to TD children. These results suggest that children with SLD experience greater anxiety, which may partially stem from reading specifically. The finding of avoidance rather than vigilance to reading stimuli indicates the use of more top-down attentional control. This work has important implications for therapeutic approaches to anxiety in children with SLD and highlights the need for attention to socio-emotional difficulties in this population. Future research is needed to further investigate the cognitive aspects of socio-emotional difficulties in children with SLD, as well as how this may impact academic outcomes.
Asunto(s)
Ansiedad/fisiopatología , Sesgo Atencional/fisiología , Miedo/fisiología , Lectura , Trastorno Específico de Aprendizaje/fisiopatología , Adolescente , Niño , Femenino , Humanos , MasculinoRESUMEN
An association between learning disorders and coordination problems has been reported in several studies over the last few decades. In this study, we have investigated daily motor characteristics in children with a diagnosis of specific learning disorder (SLD) and compared them with those of children with developmental coordination disorder (DCD) and those of typically developing controls. Ninety-six children aged 5 to 12 years were included: 29 with a diagnosis of SLD, 33 of DCD, and 34 controls. The Italian version of the Developmental Coordination Disorder Questionnaire 2007 (DCDQ-Italian) was used to measure children's coordination in everyday functional activities. The mean DCDQ-Italian total score was significantly lower in both SLD and DCD groups as compared with controls. Regarding subscores, both clinical groups scored significantly lower than controls on "Fine motor/handwriting" skills and on "General coordination." The DCD group scored also significantly lower than controls on "Control during movement." Moreover, clinical groups differed from each other, with SLD children scoring significantly higher on "Control during movement" and "General coordination" subscores. SLD children diverged from typically developing children in some motor skills during ordinary activities, and although this discrepancy was not as severe as in DCD children, it could have an impact on self-esteem and sport inclusion.
Asunto(s)
Trastornos de la Destreza Motora/fisiopatología , Trastorno Específico de Aprendizaje/fisiopatología , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Escritura Manual , Humanos , Masculino , Trastornos de la Destreza Motora/complicaciones , Movimiento/fisiología , Trastorno Específico de Aprendizaje/complicacionesRESUMEN
Sequential regression was used to evaluate whether language-related working memory components uniquely predict reading and writing achievement beyond cognitive-linguistic translation for students in Grades 4 through 9 ( N = 103) with specific learning disabilities (SLDs) in subword handwriting (dysgraphia, n = 25), word reading and spelling (dyslexia, n = 60), or oral and written language (oral and written language learning disabilities, n = 18). That is, SLDs are defined on the basis of cascading level of language impairment (subword, word, and syntax/text). A five-block regression model sequentially predicted literacy achievement from cognitive-linguistic translation (Block 1); working memory components for word-form coding (Block 2), phonological and orthographic loops (Block 3), and supervisory focused or switching attention (Block 4); and SLD groups (Block 5). Results showed that cognitive-linguistic translation explained an average of 27% and 15% of the variance in reading and writing achievement, respectively, but working memory components explained an additional 39% and 27% of variance. Orthographic word-form coding uniquely predicted nearly every measure, whereas attention switching uniquely predicted only reading. Finally, differences in reading and writing persisted between dyslexia and dysgraphia, with dysgraphia higher, even after controlling for Block 1 to 4 predictors. Differences in literacy achievement between students with dyslexia and oral and written language learning disabilities were largely explained by the Block 1 predictors. Applications to identifying and teaching students with these SLDs are discussed.
Asunto(s)
Éxito Académico , Agrafia/fisiopatología , Atención/fisiología , Dislexia/fisiopatología , Trastornos del Desarrollo del Lenguaje/fisiopatología , Alfabetización , Memoria a Corto Plazo/fisiología , Trastorno Específico de Aprendizaje/fisiopatología , Adolescente , Niño , Femenino , Humanos , MasculinoRESUMEN
The heterogeneity among children with learning disabilities still represents a barrier and a challenge in their conceptualization. Although a dimensional approach has been gaining support, the categorical approach is still the most adopted, as in the recent fifth edition of the Diagnostic and Statistical Manual of Mental Disorders. The introduction of the single overarching diagnostic category of specific learning disorder (SLD) could underemphasize interindividual clinical differences regarding intracategory cognitive functioning and learning proficiency, according to current models of multiple cognitive deficits at the basis of neurodevelopmental disorders. The characterization of specific cognitive profiles associated with an already manifest SLD could help identify possible early cognitive markers of SLD risk and distinct trajectories of atypical cognitive development leading to SLD. In this perspective, we applied a cluster analysis to identify groups of children with a Diagnostic and Statistical Manual-based diagnosis of SLD with similar cognitive profiles and to describe the association between clusters and SLD subtypes. A sample of 205 children with a diagnosis of SLD were enrolled. Cluster analyses (agglomerative hierarchical and nonhierarchical iterative clustering technique) were used successively on 10 core subtests of the Wechsler Intelligence Scale for Children-Fourth Edition. The 4-cluster solution was adopted, and external validation found differences in terms of SLD subtype frequencies and learning proficiency among clusters. Clinical implications of these findings are discussed, tracing directions for further studies.
Asunto(s)
Trastorno Específico de Aprendizaje/clasificación , Trastorno Específico de Aprendizaje/fisiopatología , Escalas de Wechsler , Adolescente , Niño , Análisis por Conglomerados , Femenino , Humanos , MasculinoRESUMEN
This study examined performance in the forward and backward digit span task of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) in a large group of children with specific learning disorder (SLD) as compared with a group of typically developing children matched for age and sex. Our results further support the hypothesis that the intellectual difficulties of children with SLD involve working memory in the forward digit span task to a greater extent than in the backward digit span task. The correlation of the two spans with a General Ability Index (GAI) was similar in SLD, and smaller in magnitude than in typically developing children. Despite a GAI within normal range, children with SLD had difficulty with both digit span tasks, but more so for forward span. This pattern was similar for different SLD profiles with clinical diagnoses of dyslexia and mixed disorder, but the impairments were more severe in the latter. Age differences were also investigated, demonstrating larger span impairment in older children with SLD than in younger.
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Memoria a Corto Plazo/fisiología , Recuerdo Mental/fisiología , Trastorno Específico de Aprendizaje/diagnóstico , Trastorno Específico de Aprendizaje/fisiopatología , Adolescente , Estudios de Casos y Controles , Niño , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Estadística como Asunto , Escalas de WechslerRESUMEN
The fifth edition of theDiagnostic and Statistical Manual of Mental Disordersgrouped specific learning disabilities in the single diagnostic category of specific learning disorder (SLD), with specifiers for impairments in reading, written expression, and mathematics. This study aimed at investigating the intellectual profile, assessed with the fourth edition of theWechsler Intelligence Scale for Children(WISC-IV), of 172 children with a diagnosis of SLD, compared to 74 clinical referral controls. WISC-IV intellectual functioning in children with SLD was characterized by a significant discrepancy between general ability and cognitive proficiency (General Ability Index [GAI] > Cognitive Proficiency Index [CPI]), and worse performances on the Similarities, Digit Span, Letter-Number Sequencing, and Coding subtests, supporting models of multiple cognitive deficits at the basis of neurodevelopmental disorders as SLD. GAI was the best and more conservative measure provided by the WISC-IV to identify intellectual functioning in children with SLD, and the intellectual discrepancy between GAI and CPI could be considered a "cognitive sign" for the presence of SLD in a single diagnostic category. Cognitive deficits differed in subtypes of impairment (reading, written expression, and mathematics), supporting their distinction for empirical, educational, and rehabilitative purposes. These findings need further replication in larger samples and in comparison to typically developing children.
Asunto(s)
Discalculia/fisiopatología , Dislexia/fisiopatología , Trastorno Específico de Aprendizaje/fisiopatología , Escalas de Wechsler/estadística & datos numéricos , Adolescente , Niño , Discalculia/clasificación , Discalculia/epidemiología , Dislexia/clasificación , Dislexia/epidemiología , Femenino , Humanos , Italia/epidemiología , Masculino , Trastorno Específico de Aprendizaje/clasificación , Trastorno Específico de Aprendizaje/epidemiologíaRESUMEN
High comorbidity rates between reading disorder (RD) and mathematics disorder (MD) indicate that, although the cognitive core deficits underlying these disorders are distinct, additional domain-general risk factors might be shared between the disorders. Three domain-general cognitive abilities were investigated in children with RD and MD: processing speed, temporal processing, and working memory. Since attention problems frequently co-occur with learning disorders, the study examined whether these three factors, which are known to be associated with attention problems, account for the comorbidity between these disorders. The sample comprised 99 primary school children in four groups: children with RD, children with MD, children with both disorders (RD+MD), and typically developing children (TD controls). Measures of processing speed, temporal processing, and memory were analyzed in a series of ANCOVAs including attention ratings as covariate. All three risk factors were associated with poor attention. After controlling for attention, associations with RD and MD differed: Although deficits in verbal memory were associated with both RD and MD, reduced processing speed was related to RD, but not MD; and the association with RD was restricted to processing speed for familiar nameable symbols. In contrast, impairments in temporal processing and visuospatial memory were associated with MD, but not RD.
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Atención/fisiología , Discalculia/fisiopatología , Dislexia/fisiopatología , Memoria a Corto Plazo/fisiología , Desempeño Psicomotor/fisiología , Trastorno Específico de Aprendizaje/fisiopatología , Percepción del Tiempo/fisiología , Niño , Comorbilidad , Discalculia/epidemiología , Dislexia/epidemiología , Femenino , Humanos , Masculino , Factores de Riesgo , Trastorno Específico de Aprendizaje/epidemiologíaRESUMEN
This study investigates nonspeech and speech processing in specific language impairment (SLI) and dyslexia. We used a passive mismatch negativity (MMN) task to tap automatic brain responses and an active behavioural task to tap attended discrimination of nonspeech and speech sounds. Using the roving standard MMN paradigm, we varied the number of standards ('few' vs. 'many') to investigate the effect of sound repetition on N100 and MMN responses. The results revealed that the SLI group needed more repetitions than dyslexics and controls to create a strong enough sensory trace to elicit MMN. In contrast, in the behavioural task, we observed good discrimination of speech and nonspeech in all groups. The findings indicate that auditory processing deficits in SLI and dyslexia are dissociable and that memory trace formation may be implicated in SLI.