Abstract
Event plausibility facilitates the processing of affirmative sentences, but little is known about how it affects negative sentences. In six behavioural experiments, we investigated negation's impact on the choice of sentence continuations that differ with respect to event plausibility. In a four-choice cloze task, participants saw affirmative and negative sentence fragments (The child will [not] eat the . . .) in combination with four potential continuations: yoghurt (a plausible word), shellfish (a weak world knowledge violating word), branch (a severe world knowledge violating word), and minivan (a word resulting in a semantic violation). Across all experiments the plausible word was highly preferred in both affirmative and negative sentences. Experiment 2 replicated Experiment 1 while ruling out the possibility that the lack of effect of negation in Experiment 1 stemmed from participants not fully processing the negation. Experiment 3 showed that the observed plausibility effects can be generalised to other aspectual forms (The child has [not] eaten the yoghurt). Experiment 4 ruled out the possibility that the choices were mainly driven by lexical associations and additionally suggested a role for informativity. Experiment 5 replicated Experiment 4 and reinforced the general pattern according to which negative sentences express the denial of plausible positive events. Experiment 6 provided evidence that informativity might be driving patterns of choices in the negative sentences. All in all, these findings suggest that upcoming continuations are chosen to maximise the plausibility of the event in the affirmative sentences and to deny that event in the negative sentences. The observed plausibility effects do not seem to be modulated by the internal representation of events, but they can be modulated by changes to the expected informativity of the sentence.