N400 and P600 modulation in presupposition accommodation: the effect of different trigger types

This study investigates the neurophysiological correlates of presupposition processing inconditions of satisfaction and accommodation, comparing two types of triggers: definitedescriptions and change-of-state verbs. Results showed that, for both types, the accom-modation of presuppositions is associated with a biphasic N400-P600 pattern at theprocessing point. With definite descriptions, we observed a more clear involvement of theN400, while for change-of-state verbs the costs of accommodation were associated with amore pronounced P600. Moreover, when conveyed by change of state predicates, pre-suppositions seem to elicit also a P200 visible already at the trigger verb. The data nicelyfitinto the Linking-Updating model and support two main conclusions. First, presuppositionaccommodation is a sequential process unfolding through a biphasic ERP pattern pre-sumably related to search for antecedent and discourse update. Second, the kind of presupposition trigger seems to affect the cognitive cost of presupposition accommodation atdifferent processing times, with definite description capitalizing more on the earlier searchfor antecedent and change-of-state verbs capitalizing more on the later updating of thediscourse mental model with the presupposed information. Overall, ourfindings suggestthat the brain understands information taken for granted by going through a processwhose time course involves several phases, differently modulated based on specific linguistic expression.