Quantity Matters: Children With Dyslexia Are Impaired in a Small, but Not Large, Number of Exposures During Implicit Repeated Sequence Learning.

Purpose: The present study investigated the onset of statistical learning and examined whether the number of exposures to a repeated sequence influences the learning performance of children with dyslexia on a serial reaction time task.

Method: Three groups of children (29 with dyslexia, 29 age-matched controls, and 30 reading level-matched controls) were administered a serial reaction time task, and their statistical learning performances after a small and a large number of exposures (40 vs. 180 exposures) were recorded and compared.

Results: Children with dyslexia showed impaired statistical learning after a small number of exposures to a sequence, but intact statistical learning after a large number of exposures. In contrast, the age-matched and reading level-matched control groups showed intact statistical learning after both small and large numbers of exposures. Children with dyslexia also exhibited a slower learning rate than either control group.

Conclusion: These results suggest that the amount of exposure to statistical patterns influences statistical learning performance in children with dyslexia.