Same Sentences, Different Grammars, Different Brain Responses: An MEG study on Case and Agreement Encoding in Hindi and Nepali Split-Ergative Structures

At first glance, the brain's language network appears to be universal, but languages clearly differ. How does the language network adapt to the specific details of individual grammatical systems? Here, we present an MEG study on case and agreement in Hindi and Nepali. Both languages use split-ergative case systems. However, these systems interact with verb agreement differently - in Hindi, case features conspire to determine which noun phrase (NP) the verb agrees with, but not in Nepali. We found that left inferior frontal and left anterior temporal regions are sensitive to case features in both languages. However, the left temporoparietal junction shows a unique sensitivity to specific combinations of subject and object case morphology. We suggest that this brain response unique to Hindi reflects the need to determine which NP agrees with the verb, a specific property of Hindi grammar. This shows that brain activity reflects psycholinguistic processes that are intimately tied to grammatical features. ### Competing Interest Statement The authors have declared no competing interest.