Binding deficits within the visual domain: an associative deficit characteristic of developmental dyslexia or merely a limitation in working memory capacity?

Abstract

Dyslexics have reading difficulties which originate from the inability to accurately store and retrieve associations between a visual representation (grapheme) and the corresponding verbal representation (phoneme) in long term memory. This associative deficit across the visual and verbal domain is characteristic of a dyslexic profile and we investigated the possibility that this deficit may also occur between associations within the same domain. We used separate recognition and recall tasks to address how efficiently dyslexic participants could store representations of single feature and multi-feature objects in working memory. After a delay participants had to recognise a change or recall an object when cued by location. Performance was compared to normal language individuals. The results showed that dyslexic participants appeared to store multiple features of an object with no more difficulty than a single feature which suggests multi-feature objects were stored as one integrated unit in working memory, whereas non-dyslexics demonstrated difficulty in binding multiple features. The current results do not support the idea that dyslexic individuals exhibit an associative deficit within the visual domain and that this deficit is specific to cross-domain associations.