Presupposition projection from disjunction in online processing

Abstract

Stalnaker (1973, 1974) suggested that presuppositions are evaluated dynamically in a way that crucially takes into account the ‘left-to-right’ unfolding of linguistic expressions. Recently, even more explicit considerations of the timing of online processing have been invoked to account for patterns of presupposition projection (e.g. Schlenker, 2008, 2009; Chemla and Schlenker, 2012; Hirsch and Hackl, 2014). However, relatively little is known about the actual time course of presupposition interpretation, in particular in environments that involve projection. In this paper, we take disjunction as our testing ground, and use visual world eye tracking data to shed light on the unfolding of presupposition projection in real time. Our key generalization is that presuppositions are evaluated immediately when the interpreter encounters the trigger in the left-to-right parse, bearing out a key assumption in the relevant theoretical literature, namely that presupposition projection can be related to incremental processing.