Naming speed in dyslexia and dyscalculia
Received 15 May 2007;
revised 7 January 2008;
accepted 21 January 2008.
Available online 11 February 2008.
In four carefully selected samples of 8- to 10-year old children with dyslexia (but age adequate arithmetic skills), dyscalculia (but age adequate reading skills), dyslexia/dyscalculia and controls a domain-general deficit in rapid automatized naming (RAN) was found for both dyslexia groups. Dyscalculic children exhibited a domain-specific deficit in rapid naming of quantities. This finding is in line with recent assumptions that dyscalculia is associated with a neurobiological deficit in the processing of numerosities. In the dyslexia/dyscalculia group, RAN deficits were additive, that is, the dyslexia/dyscalculia group exhibited the sum of the deficits found in the dyslexia only and dyscalculia only groups. This finding suggests that the cognitive bases of dyslexia and dyscalculia are independent from each other. Within the naming speed paradigm no differential impact of special demands on the executive functions inhibition and shifting was found for any of the four groups.
Keywords: Rapid naming; Dyslexia; Dyscalculia; Comorbidity; Executive functions
Corresponding author. Department of Psychology, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.