Event Related Potentials reveal anomalous morphosyntactic processing in developmental dyslexia

In the light of the literature describing oral language difficulties in Developmental Dyslexia (DD), Event-Related Potentials were used in order to compare morphosyntactic processing in 16 adults with DD (aged 20-28 years) and unimpaired controls. Sentences including subject-verb agreement violations were presented auditorily, with grammaticality and subject number as main factors. Electrophysiological data revealed differences between groups concerning both the latency of the P600 component, and the additional presence in the DD group of a negativity broadly diffused all over the scalp. Moreover, these electrophysiological anomalies increased when plural sentences were processed. On the whole, the results support the hypothesis of a linguistic deficit and of different language processing modalities in DD participants.