Figure 2.

fMRI response to rapid auditory stimuli in normal and dyslexic readers (P < 0.025). (a) Normal readers (n = 10) show significant difference between rapid and slow nonspeech analogues in left prefrontal cortex. Normalized, averaged functional maps are overlaid on the smoothed averaged anatomies of 10 subjects. (b) Dyslexic readers (n = 8) show (on the smoothed averaged anatomies of dyslexic readers) no differential left frontal response to rapid stimuli. (c) Group difference in brain activity. Region shows significant group by stimulus interaction; normal readers had more activity than the dyslexic readers for the rapid versus slow comparison. AC-PC, anterior-posterior commissive plane.