TY - JOUR
T1 - Investigating the central executive in adult dyslexics
T2 - Evidence from phonological and visuospatial working memory performance
AU - Smith-Spark, James H.
AU - Fisk, John E.
AU - Fawcett, Angela J.
AU - Nicolson, Roderick I.
N1 - Funding Information:
Requests for reprints should be addressed to J. Smith-Spark, Dept of Psychology, Keynes College, University of Kent at Canterbury, CT2 7NP, UK. Email: [email protected] This work was supported by a Medical Research Council PhD studentship awarded to the first author. We are grateful to Professor Alan Baddeley, Dr Jackie Andrade, Professor Keith Rayner, and two anonymous reviewers for comments made on earlier versions of this work.
PY - 2003/10/1
Y1 - 2003/10/1
N2 - There is long-standing evidence for verbal working memory impairments in both children and adults with dyslexia. By contrast, spatial memory appears largely to be unimpaired. In an attempt to distinguish between phonological and central executive accounts of the impairments in working memory, a set of phonological and spatial working memory tasks was designed to investigate the key issues in working memory, task type, task demands (static, dynamic, and updating), and task complexity. Significant differences emerged between the dyslexic and nondyslexic participants on the verbal working memory tasks employed in Experiment 1, thereby providing further evidence for continuing dyslexic impairments of working memory into adulthood. The nature of the deficits suggested a problem with the phonological loop, with there being little evidence to implicate an impairment of the central executive. Due to the difficulties associated with separating verbal working memory and phonological processing, however, performance was investigated in Experiment 2 using visuospatial measures of working memory. The results of the visuospatial tasks indicated no between-group differences in static spatial memory, which requires the short-term storage of simultaneously presented information. In almost all conditions there were no between-group differences in dynamic spatial memory that demands the recall of both location and order of stimuli presented sequentially. However, a significant impairment occurred on the dynamic task under high memory updating load, on which dyslexic adults showed nonphonological working memory deficits. In the absence of an explanation involving verbal recoding, this finding is interpreted in terms of a central executive or automaticity impairment in dyslexia.
AB - There is long-standing evidence for verbal working memory impairments in both children and adults with dyslexia. By contrast, spatial memory appears largely to be unimpaired. In an attempt to distinguish between phonological and central executive accounts of the impairments in working memory, a set of phonological and spatial working memory tasks was designed to investigate the key issues in working memory, task type, task demands (static, dynamic, and updating), and task complexity. Significant differences emerged between the dyslexic and nondyslexic participants on the verbal working memory tasks employed in Experiment 1, thereby providing further evidence for continuing dyslexic impairments of working memory into adulthood. The nature of the deficits suggested a problem with the phonological loop, with there being little evidence to implicate an impairment of the central executive. Due to the difficulties associated with separating verbal working memory and phonological processing, however, performance was investigated in Experiment 2 using visuospatial measures of working memory. The results of the visuospatial tasks indicated no between-group differences in static spatial memory, which requires the short-term storage of simultaneously presented information. In almost all conditions there were no between-group differences in dynamic spatial memory that demands the recall of both location and order of stimuli presented sequentially. However, a significant impairment occurred on the dynamic task under high memory updating load, on which dyslexic adults showed nonphonological working memory deficits. In the absence of an explanation involving verbal recoding, this finding is interpreted in terms of a central executive or automaticity impairment in dyslexia.
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U2 - 10.1080/09541440340000024
DO - 10.1080/09541440340000024
M3 - Article (journal)
AN - SCOPUS:0142136612
SN - 0954-1446
VL - 15
SP - 567
EP - 587
JO - European Journal of Cognitive Psychology
JF - European Journal of Cognitive Psychology
IS - 4
ER -