Memoria de Trabajo e Inteligencia General Fluida en un Grupo de Escolares del Nivel Primario / Working Memory and Fluid General Intelligence in a Children Scholar Group

Resumen El presente estudio tiene dos objetivos: a) Construir un Test de Capacidad de Lectura -TCL, para medir el nivel de memoria de trabajo (MT) y b) analizar la relación entre MT y la inteligencia general fluida -Gf (medido a través de Test de Matrices Progresivas de Raven, para niños), en un grupo de 124 niños lectores escolarizados del nivel primario. Dado el carácter primordial de este segundo objetivo, se procedió a emplear el método correlacional, que sugiere la medición y descripción de las variables MT y Gf, cuyo índice correlacional establece el nivel de dicha relación. En cuanto a la justificación de la presente tesis, se sustenta en la constatación empírica de la presencia previa de la MT, como un factor explicativo de la varianza que sufre la Gf. La validez de contenido del nuevo TCL se estableció mediante el criterio de juicio de expertos; mientras que, la confiabilidad del mismo instrumento está dentro del nivel de confianza y seguridad. Finalmente, se puede afirmar que la relación entre MT y Gf es sustancial, en la medida que sugiere que la MT es un factor importante que explica la varianza de los puntajes Gf.

Abstract The present study have two objectives: a) Elaborate a Reading Span Test -RST, that measure the level of working memory (WM), and b) analyze the relation between WM and fluid general intelligence -Gf (measured with Raven´s Progressive Matrices Test, for children), in a group of 124 children of the primary school level. The first objective was reached according to the theoretical and techniques suggestions offered by Daneman & Carpenter (1980) in order to construct a new version of RST, sustained by WM model, originally proposed by Baddeley & Hitch (1974). WM is a cognitive system of limited capacity, in which acts simultaneously, storage and processing information mechanisms. This cognitive system is involved in diverse complex cognitive activities, such as, reading comprehension, learning, and reasoning. The content validity of the new RST was done through expert judgment; while the reliability of same instrument was got accord Kuder/ Richardson-20 coefficient r 11 = 0.87, that guarantee the reliability of the instrument. Respect to the second objective, it was found a coefficient of correlation Eta2 = 0.525, which means that relation is substantial, therefore confirms that WM is an important factor by which cause the variance of scores of the Gf is 27.6%.

Brain activation for reading and listening comprehension: an fMRI study of modality effects and individual differences in language comprehension

The study compared the brain activation patterns associated with the comprehension of written and spoken Portuguese sentences. An fMRI study measured brain activity while participants read and listened to sentences about general world knowledge. Participants had to decide if the sentences were true or false. To mirror the transient nature of spoken sentences, visual input was presented in rapid serial visual presentation format. The results showed a common core of amodal left inferior frontal and middle temporal gyri activation, as well as modality specific brain activation associated with listening and reading comprehension. Reading comprehension was associated with more left-lateralized activation and with left inferior occipital cortex (including fusiform gyrus) activation. Listening comprehension was associated with extensive bilateral temporal cortex activation and more overall activation of the whole cortex. Results also showed individual differences in brain activation for reading comprehension. Readers with lower working memory capacity showed more activation of right-hemisphere areas (spillover of activation) and more activation in the prefrontal cortex, potentially associated with more demand placed on executive control processes. Readers with higher working memory capacity showed more activation in a frontal-posterior network of areas (left angular and precentral gyri, and right inferior frontal gyrus). The activation of this network may be associated with phonological rehearsal of linguistic information when reading text presented in rapid serial visual format. The study demonstrates the modality fi ngerprints for language comprehension and indicates how low- and high working memory capacity readers deal with reading text presented in serial format.

Capacidad de la memoria de trabajo verbal: Validez y fiabilidad de una tarea de amplitud de lectura / Verbal working memory capacity: Reliability and validity of the reading span task

La memoria de trabajo se refiere a todos aquellos mecanismos o procesos implicados en el control, regulación y mantenimiento activo de información relevante para la ejecución de tareas cognitivas complejas (Miyake & Shah, 1999); es uno de los principales factores limitantes de las capacidades de alto nivel jerárquico, como el razonamiento o la comprensión lectora. En este trabajo se informa un estudio en el que se analizaron las propiedades psicométricas de una de las tareas más conocidas para la evaluación de la capacidad de la memoria de trabajo, la Tarea de Amplitud de Lectura de Daneman y Carpenter (1980). La tarea consiste en leer un conjunto de oraciones no relacionadas entre sí, mientras se retienen sus palabras finales, y determina el máximo número de palabras finales que un participante puede recordar, que se identifica con su amplitud o span. La prueba se adaptó al español rioplatense partiendo de versiones españolas (Elosúa, Gutiérrez, García Madruga, Luque & Gárate, 1996; Gutiérrez, Jiménez & Castillo, 1996) y se administró en sesión individual a 132 voluntarios, conjuntamente con pruebas estandarizadas de memoria de corto plazo y de trabajo, tales como Amplitud de Dígitos y Amplitud Viso-Espacial de la Wechsler Memory Scale - Revised (WMS - R, Wechsler & Stone, 1987) y Ordenamiento Dígito-Letra de la Wechsler Adult Intelligence Scale III (WAIS III - Wechsler, 1987). La tarea de Amplitud de Lectura mostró una alta fiabilidad. Con respecto a su validez, se obtuvieron correlaciones significativas con tareas de memoria verbal, pero no así con tareas de memoria viso-espacial.

In the study of human behavior, working memory has been seen as a central construct (Conway, Kane, Bunting, Hambrick, Wilhelm, & Engle, 2005) since the cognitive revolution took place. Working memory refers to those mechanisms or processes that are involved in the control, regulation, and active maintenance of task-relevant information in the service of complex cognition (Miyake & Shah, 1999), and is considered one of the main limiting factors for complex abilities such as reasoning or reading comprehension. Methodologically, the Reading Span Task (Daneman & Carpenter, 1980) has proven to be both a reliable and valid measure of working memory capacity, and is a widely used measure. The purpose of this study was to develop a local adaptation of the Reading Span Task, based on two previous Spanish versions (Gutiérrez, Jiménez, & Castillo, 1996; Elo súa, Gutiérrez, García Madruga, Luque, & Gárate, 1996), whose psychometric properties were not known. In both cases, the Reading Span capacity was significantly correlated with measures of reading comprehension. However, the psychometric properties of the Reading Span Task were not analyzed. The task requires participants to read a set of unrelated sentences, each of which is between 12 and 14 words long, one sentence at a time, at their own pace. Sentences are arranged in 4 sets of 2, 3, 4, and 5 sentences. There are three different trials at each set-size (number of sentences) level. After having read all the sentences in each set, participants try to recall the final word of each sentence. Working memory capacity is both the maximum number of sentences for which the participant can recall the final word (Span) and the total number of sentence-final words recalled (Conway et al., 2005). The task was administered in one session to 132 undergraduates at the University of Buenos Aires (UBA), along with other standardized short-term and working memory tests, Digit Span and Visuo-Spatial Span from the Wechsler Memory Scale - Revised (Wechsler & Stone, 1987), and Letter- Number Sequencing from the Wechsler Adult Intelligence Scale III (Wechsler, 2003). The Reading Span Task showed high reliability (α = .95). The percentile analysis shows that those participants that obtained a Span of 2 or recalled 6 words fall in the 25th percentile, while those that obtained scores above a Span of 3.5 and recalled more than 24 words fall above the 75th percentile. The correlation analysis shows that the Reading Span Task has positive and significant correlations with verbal memory tasks (measured by Span, Forward Digit Span r = .408; p < .01; Backward Digit Span r = .502; p < .01; Letter-Number Sequencing r = .504; p < .01; measure by Number of sentencefinal words recalled, Forward Digit Span r = .416; p < .01; Backward Digit Span r = .496; p < .01; Letter-Number Sequencing r = .489; p < .01) , but not with visuo-spatial memory tasks (measure by Span, Forward Visuo-Spatial Span r = .169; p = n.s.; Backward Visuo-Spatial Span r = .018; p = n.s.; measure by Number of sentence-final words recalled, Forward Visuo-Spatial Span r = .189; p < .05; Backward Viso- Spatial Span r = .032; p = n.s.). A factor analysis showed the separation of the two factors involved in the tasks: a verbal factor whose capacity is affected by the Reading Span Task, Digit Span and Letter - Number Sequencing tasks, and a visuo-spatial factor whose capacity is affected by the visuo-spatial amplitude tasks. Results indicate that the Reading Span Task can be considered an appropriate, valid and reliable measure of the capacity of verbal working memory, useful for doing research on cognitive processes and for neuropsychological assessment.