Processing presuppositions: Dynamic semantics vs pragmatic enrichment

One defining and yet puzzling feature of linguistic presuppositions is the way they interact with linguistic operators. For instance, when a presupposition trigger (e.g., realise) occurs under negation (e.g., Zoologists do not realise that elephants are mammals), the sentence is most commonly interpreted with the same global presupposition (elephants are mammals) as if negation was not present. Alternatively, the presupposition may be locally accommodated, i.e., the presupposition may become part of what is negated. In this paper, we develop and test two processing accounts of presupposition projection, the global-first model and the local-first model, inspired by dynamic semantics and pragmatic theories respectively. We tested these predictions using a verification task similar to Bott and Noveck's test of default models of scalar implicature. Across two experiments, using different materials and instructions, participants were faster to derive the global interpretation than the local interpretation, in contrast to the local-first model. We discuss the results in terms of dynamic semantics vs pragmatic models of presupposition projection.