Phonological and visuo-spatial working memory alterations in dyslexic children

Background. Working memory allows the retention of a limited amount of info rmation for a brief period of time and the manipulation of that information . This study was undertaken to compare possible differences in working memo ry between dyslexic and control children. Methods. To test the executive central process that controls attention, sub jects were requested to assemble a 100-piece puzzle. To test the phonologic al loop, subjects were requested to repeat orally a 10-item list with the f ollowing characteristics: digits spanning two numbers; phonologically simil ar words, and unfamiliar pseudowords. The visuo-spa tial sketchpad was test ed by means of assembling a 25-piece puzzle. Results. Forty dyslexic and and forty control children were studied. Dyslex ic children recall a lesser number of similar words in the phonological loo p and spend a longer time in puzzle assembly in the visuo-spatial sketchpad . No statistical difference in the central executive process was found. Conclusions. Present results suggest the importance of visuo-spatial and ph onological loop alterations in dyslexic children that may result in difficu lties with similar words and spatial information. (C) 2001 IMSS. Published by Elsevier Science Inc.