Visual deficits in developmental dyslexia: relationships between non-linguistic visual tasks and their contribution to components of reading

Developmental dyslexia is often characterized by a visual deficit, but the nature of this impairment and how it relates to reading ability is disputed (Brain 2003; 126: 841–865). In order to investigate this issue, we compared groups of adults with and without dyslexia on the Ternus, visual‐search and symbols tasks. Dyslexic readers yielded more errors on the visual‐search and symbols tasks compared with non‐dyslexic readers. A positive correlation between visual‐search and symbols task performance suggests a common mechanism shared by these tasks. Performance on the visual‐search and symbols tasks also correlated with non‐word reading and rapid automatized naming measures, and visual search contributed independent variance to non‐word reading. The Ternus task did not discriminate reading groups nor contributed significant variance to reading measures. We consider how visual‐attention processes might underlie specific component reading measures. Copyright © 2007 John Wiley & Sons, Ltd.