Non-Adjacent Dependency Learning in Adults with Dyslexia: the Visual Domain

Abstract

There has been a lot of research on dyslexia. However, the cause of this impairment is still not clear. One potential skill underlying dyslexia could be the process of categorization. The human language system uses abstract categories on a phonological level (phonemes) and on a grammatical level. One way to examine the sensitivity to grammatical relationships is with non-adjacent dependency learning (NADL). Non-adjacent dependencies (such as is X-ing, as in ‘the bird is singing’, or the X-s, as in ‘the chairs’) were investigated with an artificial language in an experiment of Gómez (2002) and Gómez and Maye (2005). But how would people with dyslexia perform on a non-linguistic (visual) task? Is dyslexia a domain specific, or domain general problem? In the present study, young adults with and without dyslexia were presented with three-element strings, consisting of three pictures, produced by one of two visual ‘languages’. During a test phase, they were presented with element strings from both languages (grammatical and ungrammatical ones). Subjects could only distinguish the ‘languages’ if they had acquired the non-adjacent dependencies. Results show that subjects said ‘yes’ more often to grammatical strings than to ungrammatical strings, indicating sensitivity to the dependencies. However, no difference was found on the performance of the task between dyslexics and controls.