Processing temporal presuppositions: an event-related potential study

The ability to efficiently process presuppositions, which contain information that the speaker believes to be in the background to the conversation, is essential for effective communication. To get a deeper understanding of the nature and the time-course of temporal presupposition processing, we examined event-related potential evoked by the word again in two types of sentence contexts. The word again was presented in contexts that supported a presupposition (e.g. Jake had tipped a maid at the hotel once before. Today he tipped a maid at the hotel again...) or violated it (e.g. Jake had never tipped a maid at the hotel before. Today he tipped a maid at the hotel again...). The presupposition violation was associated with increased amplitudes of the P3b/P600 but not the N400 component. We argue for the centrality of the P3b/P600 component for presupposition processing. These findings demonstrate rapid integration of lexical presuppositions with contextual knowledge.