Cognitive control in dyslexia: investigating the competition resolution in verbal and non-verbal tasks

Goranova, Zheni (2019). Cognitive control in dyslexia: investigating the competition resolution in verbal and non-verbal tasks. University of Birmingham. Ph.D.

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Abstract

Developmental Dyslexia is a characterised with difficulties in literacy acquisition, despite normal intelligence and sufficient educational exposure. The heterogeneous profile of developmental dyslexia includes not only reading related deficits, but also cognitive processing deficits that extend beyond the language domain. In this thesis, I investigated how adults with dyslexia (AwD) resolve competition in verbal and non-verbal tasks. In the first study, the results indicated that AwD experience increased lexical competition. In particular, they exhibited poorer accuracy in the more competitive conditions of the verbal tasks and also increased rates of semantically related errors. I further explored if the increased lexical competition in AwD was part of domain-general control deficit by administrating non-verbal competition tasks. I found group differences only in some of the non-verbal tasks, with AwD experiencing slower response times in the competitive conditions. However, the non-verbal task performance was not related to the lexical tasks, which suggest against AwD deficit in general cognitive control. I also found that the suppression deficit in the non-verbal tasks were secondary to their language difficulty, which is most likely due to low-level processing deficits. Therefore, the main contribution to knowledge of this thesis is the obtaining of empirical evidences for the existence of domain specific competition deficits in AwD.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):