Predictability, plausibility and possibility

Late positive event-related potential (ERP) components occurring after the N400,traditionally linked to reanalysis due to syntactic incongruence, are increasinglyconsidered to also reflect reanalysis and repair due to semantic difficulty.Semantic problems can have different origins, such as a mismatch of specificpredictions based on the context, low plausibility, or even semantic impossibilityof a word in the given context. DeLong, Quante & Kutas (2014) provided the firstdirect evidence for topographically different late positivities for prediction mismatch(left frontal late positivity for plausible but unexpected words) and plausibilityviolation (posterior-parietal late positivity for implausible, incongruent words).The aim of the current study is twofold: (1) to replicate this dissociation of ERPeffects for plausibility violations and prediction mismatch in a different language, and(2) to test an additional contrast within implausible words, comparing impossibleand possible sentence continuations. Our results replicate DeLong, Quante & Kutas(2014) with different materials in a different language, showing graded effects forpredictability and plausibility at the level of the N400, a dissociation of plausible andimplausible, anomalous continuations in posterior late positivities and an effect ofprediction mismatch on late positivities at left-frontal sites. In addition, we foundsome evidence for a dissociation, at these left-frontal sites, between implausiblewords that were fully incompatible with the preceding discourse and those for whichan interpretation is possible.