Task Demands and Sentence Reading Comprehension among Healthy Older Adults: The Complementary Roles of Cognitive Reserve and Working Memory.

Ageing entails different functional brain changes. Education, reading experience, and leisure activities, among others, might contribute to the maintenance of cognitive performance among older adults and are conceptualised as proxies for cognitive reserve. However, ageing also conveys a depletion of working memory capacity, which adversely impacts language comprehension. This study investigated how cognitive reserve proxies and working memory jointly predict the performance of healthy older adults in a sentence reading comprehension task, and how their predictive value changes depending on sentence structure and task demands. Cognitively healthy older adults (n = 120) completed a sentence-picture verification task under two conditions: concurrent viewing of the sentence and picture or their sequential presentation, thereby imposing greater demands on working memory. They also completed a questionnaire on cognitive reserve proxies as well as a verbal working memory test. The sentence structure was manipulated by altering the canonical word order and modifying the amount of propositional information. While the cognitive reserve was the main predictor in the concurrent condition, the predictive role of working memory increased under the sequential presentation, particularly for complex sentences. These findings highlight the complementary roles played by cognitive reserve and working memory in the reading comprehension of older adults.

Preserved semantic categorical organization in mild cognitive impairment: A network analysis of verbal fluency.

The decline in semantic verbal fluency as we age may originate from both semantic memory degradation and executive function deficits. We investigated to what extent semantic memory is organized into categories in older adults with mild cognitive impairment (n = 81) and healthy controls (n = 83). We obtained the semantic networks automatically from the probability of co-occurrence of words in a verbal fluency test and characterized them with graph-theory tools. We found that the degree of categorical organization was similar for both diagnostic groups, but there was a higher tendency to transition to other categories during word production in the patient group. These results suggest that the semantic network is preserved in mild cognitive impairment, but also that the existing associations are exploited less efficiently during long-term memory search, possibly because of deficits in executive function.

Morpho-syntactic reading comprehension in children with early and late cochlear implants.

This study explores morpho-syntactic reading comprehension in 19 Spanish children who received a cochlear implant (CI) before 24 months of age (early CI [e-CI]) and 19 Spanish children who received a CI after 24 months (late CI [l-CI]). They all were in primary school and were compared to a hearing control (HC) group of 19 children. Tests of perceptual reasoning, working memory, receptive vocabulary, and morpho-syntactic comprehension were used in the assessment. It was observed that while children with l-CI showed a delay, those with e-CI reached a level close to that which was obtained by their control peers in morpho-syntactic comprehension. Thus, results confirm a positive effect of early implantation on morpho-syntactic reading comprehension. Inflectional morphology and simple sentence comprehension were noted to be better in the e-CI group than in the l-CI group. The most important factor in distinguishing between the HC and l-CI groups or the e-CI and l-CI groups was verbal inflectional morphology.

El lenguaje en el envejecimiento: procesos de recuperación léxica / Language in aging: lexical retrieval processes

En los últimos años, ha existido un interés creciente por entender la naturaleza del lenguaje en el envejecimiento, no solo por tratar de describir el modo en que este dominio cambia con la edad, sino también por la particular cualidad que su complejidad e interdependencia con otros procesos cognitivos le confieren sirviendo de marco en el desarrollo de teorías generales sobre el envejecimiento, al tiempo que brindando la oportunidad de examinar los sustratos neurobiológicos asociados al deterioro funcional y la preservación cognitiva. Aunque el procesamiento lingüístico parece resistir el avance de la edad, lo cierto es que cambios asociados al proceso de envejecimiento surgen también en el lenguaje. Sin embargo, el envejecimiento no afecta al lenguaje de un modo global, sino específicamente produciendo asimetrías, entre las que destaca un marcado deterioro de la producción frente a un relativo mantenimiento de la comprensión o un aumento del vocabulario. El propósito de este trabajo es revisar los principales cambios estructurales y funcionales que acontecen en el cerebro con la edad, así como los declives que a nivel cognitivo de ellos se derivan, con particular interés en el efecto que estos cambios pueden tener en el lenguaje, y en especial en los procesos de recuperación léxica. Se considera también el efecto de factores sociales, tales como el nivel educativo y la posición socioeconómica. El artículo aborda además los déficits de acceso léxico asociados a enfermedad neurológica, concretamente a deterioro cognitivo leve y enfermedad de Alzheimer (AU)

In the last few years, interest in understanding the nature of language in aging has grown. This interest concerns how this domain changes with age. Furthermore, because of its complexity and interdependence with other cognitive processes, language provides a framework to develop general theories on aging and to examine the neurobiological substrates in relation to functional impairment and cognitive preservation. Although linguistic processes seem not to be impaired as a result of age, age-related changes do affect language. However, not all linguistic processes are affected equally. Aging causes a marked deterioration in language production versus a relative preservation of comprehension or an increase in vocabulary. The aim of this study was to review age-related changes in brain structure and function, as well as the resulting cognitive decline, with particular focus on the effect that these changes might have on language, especially on the processes of lexical retrieval. The role of social variables, such as education and socioeconomic status are also considered. Deficits in lexical access related to neurological disorders such as mild cognitive impairment and Alzheimer's disease are also discussed (AU)

Canonical word order and interference-based integration costs during sentence comprehension: the case of Spanish subject- and object-relative clauses.

Object-relative clauses are generally harder to process than subject-relative clauses. Increased processing costs for object-relatives have been attributed either to working memory demands for the establishment of long-distance dependencies or to difficulties processing unexpected, noncanonical structures. The current study uses self-paced reading to contrast the impact of both kinds of factors in Spanish object-relative clauses, manipulating the interposition of the subject of the relative clause between object and verb. In addition, object-relatives were unambiguously marked at their onset with the Spanish preposition "a". Reading times increased at the onset and final regions of object-relative clauses, regardless of interference-based working memory costs, although interference costs may affect the processing of post-relative-clause regions. These results suggest that, beyond interference-related working memory costs, end-of-clause integration processes may be affected by a preference for canonical structures, thus increasing processing difficulties when confronted with a noncanonical form.

[Grammatical comprehension in older adults, both normal and with cognitive impairment: a comparative study based on discriminant and multidimensional scaling techniques]. / Comprensión gramatical en adultos mayores y con deterioro cognitivo: un estudio comparativo basado en el análisis discriminante y el escalamiento multidimensional.

Memory and language tests are usually used to differentiate healthy elderly individuals and individuals with cognitive impairment (CI). In the latter case, there are usually no tests to assess grammatical comprehension. The aim of this paper is to explore the differences in grammatical comprehension between healthy older adults and older adults with CI, identifying the sentences that best discriminate these groups, as well as the underlying dimensions that are most relevant to the individuals. Participants were 71 elderly people, divided into two groups according to their performance on the Spanish version of the Mini Mental State Exam: normal and CI. All were given a comprehension test that included 12 kinds of sentence structures. The CI group performed significantly worse than healthy elderly group. The greatest differences were observed in the sentences adjusted to canonical order in Spanish. The sentences with higher weights in the discriminant function were the ones adjusted to the one-proposition canonical order. Propositional density was the most salient dimension in both groups. Individuals with CI had difficulty assigning thematic roles to constituents, even when it could be done by following a strategy based on the linear order of the roles.

Comprensión gramatical en adultos mayores y con deterioro cognitivo: un estudio comparativo basado en el análisis discriminante y el escalamiento multidimensional / Grammatical comprehension in older adults, both normal and with cognitive impairment: a comparative study based on discriminant and multidimensional scaling techniques

Para diferenciar a los mayores sanos de los que presentan deterioro cognitivo (DC) se emplean habitualmente pruebas de memoria y de lenguaje. Entre estas últimas no suele aparecer ninguna que evalúe la comprensión gramatical. El objetivo de este trabajo es explorar las diferencias entre mayores normales y con DC en la comprensión gramatical, determinando las oraciones que mejor discriminan entre estos grupos, así como las dimensiones subyacentes que resultan más relevantes para los sujetos. Participaron 71 personas mayores, divididas en dos grupos en función de sus resultados en el Mini Examen Cognitivo: normales y con DC. A todos se les aplicó una prueba de comprensión que incluía 12 clases de estructuras oracionales. Los mayores con DC presentan un rendimiento significativamente peor que los mayores sanos. Las mayores diferencias se observan en las oraciones ajustadas al orden canónico. Las oraciones con mayor peso en la función discriminante son las ajustadas al orden canónico de una proposición. La densidad proposicional es la dimensión más saliente en ambos grupos. Los sujetos con DC tienen dificultades en la asignación de los roles temáticos a los constituyentes, incluso cuando ésta puede realizarse siguiendo una estrategia basada en el orden lineal de los mismos (AU)

Memory and language tests are usually used to differentiate healthy elderly individuals and individuals with cognitive impairment (CI). In the latter case, there are usually no tests to assess grammatical comprehension. The aim of this paper is to explore the differences in grammatical comprehension between healthy older adults and older adults with CI, identifying the sentences that best discriminate these groups, as well as the underlying dimensions that are most relevant to the individuals. Participants were 71 elderly people, divided into two groups according to their performance on the Spanish version of the Mini Mental State Exam: normal and CI. All were given a comprehension test that included 12 kinds of sentence structures. The CI group performed significantly worse than healthy elderly group. The greatest differences were observed in the sentences adjusted to canonical order in Spanish. The sentences with higher weights in the discriminant function were the ones adjusted to the one-proposition canonical order. Propositional density was the most salient dimension in both groups. Individuals with CI had difficulty assigning thematic roles to constituents, even when it could be done by following a strategy based on the linear order of the roles (AU)