Verbal and nominal agreement: An fMRI study

Agreement computation is one of the pillars of language comprehension. In this fMRI study, we investigated the neuro-cognitive processes of agreement associated with number feature covariance in subject-verb agreement and determiner-noun concord in Spanish by creating mismatches (ella/*ellas corre, she/*they dances vs. el/*los anillo, thesg/*thepl ring). The results evidenced the engagement of a common bilateral fronto-parietal monitoring system, not language specific, and a left fronto-temporal system that seems to be specifically related to different aspects of phrase and sentence processing. In particular, the major difference was found in the anterior portion of the left MTG-STG, which we relate to fine-grained syntactic-combinatorial building mechanisms apparently controlled by the pars opercularis within the LIFG. These results suggest that general conflict-monitoring processes operate in parallel with language-specific mechanisms that are sensitive to the specificity of agreement type for the detection of feature covariance among sentence constituents. Specifically, the coupling between these frontal and temporal regions seems to be flexible enough to show sensitivity to the fine-grained combinatorial mechanisms that underlie nominal and subject-verb agreement.