Unimpaired implicit learning in children with developmental dyslexia.

Children with dyslexia have consistently been found to have a variety of deficits in motor, cognitive, and sensory processes; however, the few studies that have been reported of the implicit learning ability of these children have produced conflicting results. The present study aimed to investigate the implicit learning abilities of children with developmental dyslexia using a simple cued reaction time task which has not been studied with this group previously. Twenty-three children with developmental dyslexia and 37 normally developing children, between the ages of 8 and 10 years, participated in the task. The results were consistent with the hypothesis in demonstrating that, despite an overall slowing in response times, dyslexic children show the same degree of implicit learning as normal readers, thus, providing evidence for an unimpaired implicit learning mechanism in dyslexic individuals. These results hold implications for the underlying mechanisms of learning, as dyslexic individuals who are impaired on explicit learning tasks, such as reading, spelling and writing, are unimpaired on implicit learning tasks. They suggest the existence of two separate systems of learning, each possessing distinct mechanisms.