engleski

Success on the AB task in infants with pre-perinatal brain lesions and its relation to language development

Studies on rhesus monkeys infants have shown that a success on the AM task depends on the integrity of dorsolateral prefrontal cortex. Infants aged betwee 7.5 and 12 months show clear improvement in performance on the AB task. The success in reflected in the length of delay imposed from no delay at all to 10 or more seconds necessary to provoke an AB error. Considering the important role of the prefrontal cortex in the development of the working memory capacity, we wanted to examine whether milder pre-perinatal brain lesions have any influence on development of prefrontal functions and if they do, whether these effects have general impact on both components of the working memory - spatial and phonological, the latter of which is essential for language development. Five subjects with Intra uterine growth retardation (IUGR) and pre-perinatal ischemic and/or hemorrhagic (grad I-III) lesions as well as five healthy subjects were followed on a monthly basis. All subjects with brain lesions were included in a neuropediatrical follow-up and a detailed neurological assessment was performed. None of the mentioned subjects had hemiparesis. The Bayley Scales of Infant Development were administered to assess general infant development. A translated and adapted version of the MacArthur Communicative Development Inventory (the Infant form) was used to follow language development stages. As for the data analysis, emphasis was put on the onset time of expressive vocabulary as a reflection of phonological working memory development. A measure of success on AB was the length of felay necessary to provoke an AB error reflected in pervasive reaching. Although we have dealt with a small group of subjects which puts certain limitations to the interpretation of results, our preliminary results indicate that subjects with pre-perinatal lesions make the AB error at shorter delays than healthy subjects. A clear connection between the success at the AB task and development of the expressive vocabulary has not been found which speaks in favor of separate development trajectories of the working memory-s pgonolgical and spatial component.

AB; brain lesions

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