Agreement Processing in Dutch Adults with Dyslexia

This PhD thesis investigated the processing of agreement violations (e.g., Dat was een mooi *compliment over haar werk) in Dutch adults with dyslexia when reading or listening to sentences. We used event-related potentials (ERPs) and self-paced reading (SPR), since we were interested in the temporal aspects of agreement violation processing. Additionally, we examined whether the modality of presentation in ERP studies (listening vs. reading) influences the brain responses to agreement violations in adults with dyslexia. Finally, we explored whether the type of (dis)agreement used (gender and number disagreement and subject-verb disagreement) affects agreement violation processing in adults with dyslexia.

Our results show that, compared to adults without dyslexia, adults with dyslexia are less sensitive to ungrammaticalities in sentences. They also process agreement violations with a delay and/or exhibit different ERP effects in response to agreement violations compared to adults without dyslexia. Furthermore, our ERP experiments indicate that presentation modality seems to play a role in agreement violation processing in dyslexia, since there was a difference in results when sentences are listened to or read. Finally, we showed that both ERPs and SPR are sensitive methods of investigating agreement processing in adults with dyslexia.

In summary, our findings indicate that adults with dyslexia exhibit atypical processing of agreement violations compared to adults without dyslexia.