Attentional blink deficits observed in dyslexia depend on task demands

The attentional blink (AB) refers to a deficit in the ability to identify a second target following a first target when both appear randomly within a rapid sequence of distractor items. The AB of five adults with dyslexia (ADys) was compared with that of a group of normal adult readers. Two tasks were completed which differed in the conceptual category of the target items (a red digit or letter) relative to the distractor items (all black digits). In the digit condition, all ADys cases showed a longer AB compared to the control group. In the letter condition, all participants showed improvement in accuracy compared to the digit condition, but three ADys cases continued to have a longer AB. The results suggest that (a) AB performance depends on task requirements, and (b) the attentional system is compromised in dyslexia. However, examination of individual case performance suggests that prolonged attentional dwell time is not a core deficit in dyslexia. The results also illustrate the limitations of group comparisons in small sample studies.