Trait and state EEG indices of information processing in developmental dyslexia.

L asymmetry in beta activity in the dyslexic group, again in both tasks. Theta activity did discriminate between the two tasks in the dyslexic group. In the phonological task, task-related frontal theta in the dyslexic group was significantly different from the control group, with the former showing an increase in amplitude and the latter a decrease. In the visual task, there was no significant difference between the dyslexic and the control group, with both showing a task-related decrease in amplitude. The inter-task variations in EEG response in the dyslexic group paralleling variations in task performance are interpreted in terms of the varying engagement of a frontally-based attentional system. Inter-task consistencies of EEG response despite variations in performance are interpreted in terms of the continued application of a specific cognitive strategy.