Syntactic and semantic predictors of tense in Hindi: An ERP investigation

Although there is broad agreement that error signals generated during an unexpected linguistic event are reflected in event-related potential (ERP) components, there are at least two distinct aspects of the process that the ERP signals may reflect. The first is the content of an error, which is the local discrepancy between an observed form and any expectations about upcoming forms, without any reference to why those expectations were held. The second aspect is the cause of an error, which is a context-aware analysis of why the error arose. The current study examines the processes involved in prediction of morphological marking on verbal forms in Hindi, a split ergative language. This is a case where an error with the same local characteristics (illicit morphology) can arise from very different cues: one syntactic in origin (ergative case marking), and the other semantic in origin (a past tense adverbial). Results suggest that the parser indeed tracks the cause in addition to the content of errors. Despite the fact that the critical manipulation of verb marking was identical across cue types, the nature of the cue led to distinct patterns of ERPs in response to anomalous verbal morphology. When verbal morphology was predicted based upon semantic cues, an incorrect future tense form elicited an early negativity in the 200–400 ms interval with a posterior distribution along with a marginally significant P600 effect. In contrast, when verbal morphology was predicted based upon morphosyntactic cues, an incorrect future tense form elicited a right-lateralised anterior negativity (RAN) during the 300–500 ms interval, as well as a P600 response with a broad distribution.