Eye-movements and ERPs reveal the time course of processing negation and remitting counterfactual worlds

The ability to update our current knowledge using contextual information is a vital process during every-day language comprehension. To understand a negated statement, readers are required to cancel real-world expectations, but are not explicitly provided with an alternative model. Thus, the question of how and when a negative context influences interpretation of later events arises. We report one eye-movement study (Exp. 1) and one ERP study (Exp. 2) investigating the effects of negation on discourse processing. Prior context depicted a real-world (RW), or negated-world (NW), while the second sentence was manipulated to create RW anomalous continuations, where events included a violation of RW knowledge, and RW-congruent continuations, where the events described were congruent with RW knowledge. Results from Experiment 1 showed that the negated discourse context did not influence initial processing of the target sentence, as reflected in participants' eye-movement behaviour. Similarly, Experiment 2 revealed that the typical N400 effect to semantic violations has not been reversed by introducing a negated-world context. However, in later processing, Experiment 1 demonstrated that the negated-world context is eventually incorporated into the representation of the sentence meaning. Thus, we suggest that discourse does not always have an immediate effect on language comprehension and discuss the results in terms of a variety of accounts of representing negation. (C) 2008 Elsevier B.V. All rights reserved.