Neuroimage study on low orthographic competence group

Background: In this paper we studied the functional neural substrates underlying the performance of homophonic spelling error detecting tasks including frequent and infrequent Spanish words- through functional Magnetic Resonance Imaging (fMRI) procedure in subjects with low orthographic performance. Method: A block design was used to administer 2 visual tasks,with 2 experimental conditions each, to 8 healthy participants with low orthographic performance. In both tasks correct and misspelled Spanish words sequentially appeared. Participants were instructed to detect orthographic errorsin one task, as well as the presence of 1 specific vowel in the other. Image data were obtained from 32 axial contiguous slices and repetition time of 3 seconds. Results: Significant bilateral activations were found, especially inmedial temporal areas during the orthographic error recognition task performance, whereas upper right and left frontal regions were significantly activated while detecting a specific vowel. Conclusions: These data are consistent with the literature and suggest an association between orthographic processing and hyperactivation of bilateral cerebral areas in subjects with low orthographic skills, probably due to compensatory mechanism

Velocidad de denominación y conciencia fonológica al inicio de la enseñanza formal de la lectura

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La velocidad de denominación de letras: el mejor predictor temprano del desarrollo lector en español

This project was a longitudinal study, in 121 children, of the predictive value of naming speed and phonological awareness in learning to read and its alterations. Naming letters best predicted the execution of reading and correctly identified 63% of the children who subsequently showed difficulties in reading speed. Such difficulties have been considered the distinctive trait of dyslexia in Spanish. Some tasks of phonological awareness contributed to explaining reading efficiency and comprehension. Children with a double deficit, in naming speed and phonological awareness, had the worst performance in reading. The evaluation of naming speed at early stages can have important implications on diagnosis and intervention in children with difficulties in learning to read.En este trabajo se estudió longitudinalmente, en 121 niños, el valor predictivo de la velocidad de denominación y las habilidades fonológicas sobre el aprendizaje de la lectura y sus alteraciones. La denominación de letras predijo mejor la ejecución lectora e identificó correctamente a 63% de los niños que posteriormente presentaron dificultades en la velocidad para leer, la cual se ha considerado como el rasgo distintivo de la dislexia en español. Algunas tareas de conciencia fonológica contribuyeron a explicar la eficiencia y la comprensión lectora. Los niños con un doble déficit, en velocidad de denominación y conciencia fonológica, presentaron el peor rendimiento lector. La evaluación de la velocidad de denominación en etapas tempranas puede tener importantes implicaciones para el diagnóstico y la intervención de los niños con dificultades en el aprendizaje de la lectura

Neuroimage study on low orthographic competence group

Antecedentes: En este trabajo se estudia la implicación de regiones cerebrales en la detección de errores ortográficos de tipo homófono en palabras frecuentes e infrecuentes del español mediante Imagen por Resonancia Magnética funcional (IRMf) en sujetos de bajo desempeño ortográfico. Método: Se empleó un Diseño de Bloques para presentar visualmente 2 tareas y 2 condiciones experimentales a ocho sujetos sanos con bajo desempeño ortográfico. Se presentaron palabras correcta e incorrectamente escritas solicitándoles a los participantes, en la primera tarea, que detectaran la presencia de errores ortográficos, mientras que en la segunda se solicitaba que detectaran la presencia de una vocal específica en la palabra presentada. Las imágenes se registraron a partir de 32 cortes axiales contiguos con un tiempo de repetición de 3 segundos. Resultados: Se encontraron activaciones significativas en áreas temporales y mediales, de forma bilateral, en la tarea de reconocimiento de patrón ortográfico mientras que en la tarea de detección de vocales las activaciones significativas se observaron en la región frontal superior derecha y frontal izquierda. Conclusiones: Los resultados son congruentes con lo reportado en la bibliografía y sugieren que el pobre reconocimiento ortográfico se asocia con hiperactivación neural bilateral cuando se ejecutan tareas de este orden, a modo de un posible reclutamiento compensatorio.Background: In this paper we studied the functional neural substrates underlying the performance of homophonic spelling error detecting tasks including frequent and infrequent Spanish words- through functional Magnetic Resonance Imaging (fMRI) procedure in subjects with low orthographic performance. Method: A block design was used to administer 2 visual tasks,with 2 experimental conditions each, to 8 healthy participants with low orthographic performance. In both tasks correct and misspelled Spanish words sequentially appeared. Participants were instructed to detect orthographic errors in one task, as well as the presence of 1 specific vowel in the other. Image data were obtained from 32 axial contiguous slices and repetition time of 3 seconds. Results: Significant bilateral activations were found, especially inmedial temporal areas during the orthographic error recognition task performance, whereas upper right and left frontal regions were significantly activated while detecting a specific vowel. Conclusions: These data are consistent with the literature and suggest an association between orthographic processing and hyperactivation of bilateral cerebral areas in subjects with low orthographic skills, probably due to compensatory mechanisms

Neurofunctional activation patterns reflect differences in cognitive control associated with spelling skills in Spanish.

Introduction: There is an essential relationship between reading development and orthographic knowledge, which varies depending on a language's orthographic characteristics. In transparent orthographies, such as Spanish, that relationship is closer, where reading speed and orthographic knowledge reflect the automation of the process in which crucial participation of attention networks is assumed. Objective: The objective of this study is to compare behavioral performance and patterns of cerebral functional activity while subjects with high and low orthographic knowledge perform an attentional control task involving word recognition. Methods: Thirty right-handed participants, aged between 17 and 20 years, were selected through non-probabilistic sampling and then classified into two groups according to their level of orthographic knowledge: high (H) and low (L). Neurofunctional activity was recorded using fMRI methods during the execution of a Stroop task (words printed in color congruent and incongruent with their meaning) under two conditions: attending to the meaning (automatic processing) or the color (interference condition). Results: The L group showed greater reaction times in both conditions, as well as greater functional activity in subcortical areas. In contrast, the H group showed higher activity in cortical areas, such as left supramarginal gyrus and medial frontal gyrus in the automatic processing condition, and in the parietal lobe during interference. Conclusions: The more significant activity in the giro frontal medial of the high orthographic knowledge group could imply recruitment of greater attention and cognitive control resources, while the neurofunctional activity observed in the low group could be associated with a compensatory effect with the recruitment of subcortical areas to solve the task

Estudio de neuroimagen en sujetos con baja competencia ortográfica ante tareas ortográficas con errores homófonos

Background: In this paper we studied the functional neural substrates underlying the performance of homophonic spelling error detecting tasks including frequent and infrequent Spanish words- through functional Magnetic Resonance Imaging (fMRI) procedure in subjects with low orthographic performance. Method: A block design was used to administer 2 visual tasks,with 2 experimental conditions each, to 8 healthy participants with low orthographic performance. In both tasks correct and misspelled Spanish words sequentially appeared. Participants were instructed to detect orthographic errorsin one task, as well as the presence of 1 specific vowel in the other. Image data were obtained from 32 axial contiguous slices and repetition time of 3 seconds. Results: Significant bilateral activations were found, especially inmedial temporal areas during the orthographic error recognition task performance, whereas upper right and left frontal regions were significantly activated while detecting a specific vowel. Conclusions: These data are consistent with the literature and suggest an association between orthographic processing and hyperactivation of bilateral cerebral areas in subjects with low orthographic skills, probably due to compensatory mechanisms.Antecedentes: En este trabajo se estudia la implicación de regiones cerebrales en la detección de errores ortográficos de tipo homófono en palabras frecuentes e infrecuentes del español mediante Imagen por Resonancia Magnética funcional (IRMf) en sujetos de bajo desempeño ortográfico. Método: Se empleó un Diseño de Bloques para presentar visualmente 2 tareas y 2 condiciones experimentales a ocho sujetos sanos con bajo desempeño ortográfico. Se presentaron palabras correcta e incorrectamente escritas solicitándoles a los participantes, en la primera tarea, que detectaran la presencia de errores ortográficos, mientras que en la segunda se solicitaba que detectaran la presencia de una vocal específica en la palabra presentada. Las imágenes se registraron a partir de 32 cortes axiales contiguos con un tiempo de repetición de 3 segundos. Resultados: Se encontraron activaciones significativas en áreas temporales y mediales, de forma bilateral, en la tarea de reconocimiento de patrón ortográfico mientras que en la tarea de detección de vocales las activaciones significativas se observaron en la región frontal superior derecha y frontal izquierda. Conclusiones: Los resultados son congruentes con lo reportado en la bibliografía y sugieren que el pobre reconocimiento ortográfico se asocia con hiperactivación neural bilateral cuando se ejecutan tareas de este orden, a modo de un posible reclutamiento compensatorio

A brain connectivity characterization of children with different levels of mathematical achievement based on graph metrics.

Recent studies aiming to facilitate mathematical skill development in primary school children have explored the electrophysiological characteristics associated with different levels of arithmetic achievement. The present work introduces an alternative EEG signal characterization using graph metrics and, based on such features, a classification analysis using a decision tree model. This proposal aims to identify group differences in brain connectivity networks with respect to mathematical skills in elementary school children. The methods of analysis utilized were signal-processing (EEG artifact removal, Laplacian filtering, and magnitude square coherence measurement) and the characterization (Graph metrics) and classification (Decision Tree) of EEG signals recorded during performance of a numerical comparison task. Our results suggest that the analysis of quantitative EEG frequency-band parameters can be used successfully to discriminate several levels of arithmetic achievement. Specifically, the most significant results showed an accuracy of 80.00% (α band), 78.33% (δ band), and 76.67% (θ band) in differentiating high-skilled participants from low-skilled ones, averaged-skilled subjects from all others, and averaged-skilled participants from low-skilled ones, respectively. The use of a decision tree tool during the classification stage allows the identification of several brain areas that seem to be more specialized in numerical processing