What About Lexical Competition? Exploring the Locus of Lexical Retrieval Deficits in Adults With Developmental Dyslexia

Objective: Individuals with dyslexia do not only show deficits with reading but are also less accurate in naming pictures. This has mainly been linked to prevalent phonological deficits. However, deficits in lexical retrieval of picture names could also be due to increased lexical-semantic competition. The present study tested whether adults with dyslexia (AwDs) are more affected by a competitive lexical-semantic context than control participants. Method: Twenty-seven AwD and 34 control participants completed the blocked-cyclic picturenaming paradigm and the Hayling sentence completion task. Results: In the blocked-cyclic naming task, AwDs showed a larger semantic interference effect than controls in terms of errors, especially producing competitor errors. In the Hayling sentence completion task, AwDs made more errors than controls when asked to complete sentences with semantically unrelated words, that is, in the competitive condition. They especially produced semantically related words or antonyms to target words. Conclusions: We found that AwDs experience difficulties with resolving lexical competition that go beyond their phonological deficits. Future studies will need to establish the mechanisms behind the increased lexical competition that AwDs exhibit.