Implicit Motor and Language Learning in Developmental Dyslexia

Abstract

Traditionally, Developmental Dyslexia is considered to be a disorder of language, but besides language problems, motor skill problems have been found in developmental dyslexics as well. This study was aimed at evaluating whether the difficulties dyslexics experience in the language and motor domain can be accounted for by one underlying domain general deficit in implicit learning. It was assessed whether 1.) developmental dyslexics show evidence of poor implicit learning in both the motor and language domain, 2.) but not of poor explicit learning, and whether 3.) implicit motor and language learning skills are associated within participants. 27 adult dyslexics and 27 age-matched controls performed an artificial grammar learning task, an implicit serial reaction time task and an explicit serial reaction time task. No impairments in implicit learning were found in the dyslexic group as compared to the control group on artificial grammar learning or in learning in the implicit serial reaction time task. Also, no significant difference was found between the performance of dyslexics and controls on the explicit serial reaction time task. Performance on the artificial grammar learning task and on the implicit serial reaction time task were not correlated. Even though no significant impairment in implicit learning was found in the dyslexic group, there were indications that dyslexics did experience difficulty with some of the tasks. It remains unclear whether the difficulties dyslexics seemed to have were caused by a mild deficit in implicit learning or by a deficit in a different cognitive construct. We suggest that sustained attention may have affected performance in our tasks. Further research should be aimed at disentangling the effects of implicit learning skill and sustained attention capacity.