Impaired serial visual search in children with developmental dyslexia.

In order to test the hypothesis of attentional deficits in dyslexia, we investigated the performance of children with developmental dyslexia on a number of visual search tasks. When tested with conjunction tasks for orientation and form using complex, letter-like material, dyslexic children showed an increased number of errors accompanied by faster reaction times in comparison to control children matched to the dyslexics on age, gender, and intelligence. On conjunction tasks for orientation and color, dyslexic children were also less accurate, but showed slower reaction times than the age-matched control children. These differences between the two groups decreased with increasing age. In contrast to these differences, the performance of dyslexic children in feature search tasks was similar to that of control children. These results suggest that children with developmental dyslexia present selective deficits in complex serial visual search tasks, implying impairment in goal-directed, sustained visual attention.