On the cross-linguistic validity of electrophysiological correlates of morphosyntactic processing: A study of case and agreement violations in Basque

The present study addresses the question of whether case and verb agreement are cross linguistically equivalent during sentence processing. This question is addressed by exploring the brain mechanisms involved in processing Basque, a Subject-Object-Verb (SOV) head-final language with ergative alignment, case morphology and multiple verb agreement. Basque speakers’ ERPs were recorded during an auditory grammatical judgment task. Participants were presented with correct and incorrect sentences addressed to study ergative case and subject and object verb-agreement processing. Incorrect sentences elicited, in all cases, a P600 component, an ERP effect repeatedly reported in previous studies that explored syntactic violations similar to the present ones, although in nominative languages. The results of this study show comparable ERP responses to both subject and object agreement and indicate that specific features of agreement (number versus person) have distinct ERP correlates, at least for multiple verb agreement. In addition, the ERP signatures for the ergative case violation were comparable to the ones found by previous studies on nominative case. Overall, the present study shows that the repair and reanalysis processes involved in verb agreement and case violations are sustained by equivalent neural mechanisms across language types.