The effect of cognitive training on recall range and speed of information processing in the working memory of dyslexic and skilled readers

Research indicates that impairment of working memory may be one of the factors that impede the ability to read fluently and accurately. Although the capacity of working memory is traditionally considered to be constant, recent data point to a certain plasticity in the neural system that underlies working memory, which can be improved by training. We examined whether dyslexic readers' recall span and speed of processing in working memory can be increased, enhancing the quality of their reading. Thirty five skilled readers and twenty six dyslexic readers were trained in working memory tasks and compared to control groups of fifteen skilled and fifteen dyslexic readers who complete a self-paced reading training regime. All subjects were trained over a six-week period. Reading and working memory indicators were collected before and after the two trainings. Brain activity using measures of event-related potential (ERP) were collected for the working memory training groups by using a working memory task (Sternberg task). Result indicated after working memory training the ability to store verbal and visual-spatial information in working memory increased, and decoding, reading rate and comprehension scores improved in both groups, although the gap between the dyslexic and the control groups in reading and working memory scores remained constant. The latency of the P300 component decreased and the amplitude increased in all participants following training. No training effect in any parameter was obtained in the self-paced reading training groups. These findings support the notion of plasticity in the neural system underlying working memory and point to the relationships between larger working memory capacity and enhancement of reading skills. (C) 2010 Published by Elsevier Ltd.