Dyslexia: verbal impairments in the absence of magnocellular impairments

Sensitivity to dynamic visual and auditory stimuli was assessed in dyslexic children (Grade 7) who at school entrance had suffered from the well-established double-deficit of impaired phonological sensitivity and deficient rapid naming performance. A visual magnocellular deficit was assessed by the coherent motion detection task of the Oxford group. An auditory magnocellular deficit was assessed by the illusory sound movement perception task of Hari and Kiesilä. On both tasks our dyslexic subjects' performance was similar or even better than the performance of normally reading controls. Differences in the inclusion of ADHD cases in dyslexic samples is discussed as a potential explanation of differences in results.