Tracking lexical and syntactic processes of verb morphology with ERP

Spanish verbs have suffixes to define the temporal frame of events. These suffixes vary according to the verb conjugation. Therefore, it is possible for experimental purposes to compose nonce-verbs by attaching a suffix from one conjugation to a verb root of another. This research used sentences including verbs or nonce-verbs composed in this fashion that either agreed or disagreed with a temporal adverb antecedent. This double manipulation – of both agreement and lexicality – allowed for the temporal dissociation of morphological stripping, agreement processes and lexical recognition. The results showed early effects of agreement on the P200 component for both verbs and nonce-verbs. The impact of lexicality was observed later (400 ms after the stimulus onset), modulating the effect of agreement at this time window. Overall, the results indicate that the morphological segmentation of the verb and the processing of adverb–verb temporal agreement start before lexical access for the verb has been completed.