Two neurocognitive mechanisms of semantic integration during the comprehension of visual real-world events

& How do comprehenders build up overall meaning rep-resentations of visual real-world events? This question was examined by recording event-related potentials (ERPs) while participants viewed short, silent movie clips depicting everyday events. In two experiments, it was demonstrated that presen-tation of the contextually inappropriate information in the movie endings evoked an anterior negativity similar to the N400 com-ponent whose amplitude has been previously reported to in-versely correlate with the strength of semantic relationship between the context and the eliciting stimulus in word and static picture paradigms. However, a second, somewhat later, ERP component—a posterior late positivity—was evoked spe-cifically when target objects presented in the movie endings violated goal-related requirements of the action constrained by the scenario context (e.g., an electric iron that does not have a sharp-enough edge was used in place of a knife in a cutting bread scenario context). These findings suggest that compre-hension of the visual real world might be mediated by two neu-rophysiologically distinct semantic integration mechanisms. The first mechanism, reflected by the anterior N400-like neg-ativity, maps the incoming information onto the connections of various strengths between concepts in semantic memory. The second mechanism, reflected by the posterior late pos-itivity, evaluates the incoming information against the discrete requirements of real-world actions. We suggest that there may be a tradeoff between these mechanisms in their utility for in-tegrating across people, objects, and actions during event com-prehension, in which the first mechanism is better suited for familiar situations, and the second mechanism is better suited for novel situations. &amp