The role of causality in discourse processing: Effects of expectation and coherence relations

Research on the processing of causality has shown that causally related sentences lead to faster reading, better recall, and better comprehension than sentences that are not causally related. In this study, we investigate two ways in which causality can influence processing: through the expectation that readers may have of a causal relation and the ease with which the sentences can be related in a causal way on the basis of their content. We ran two eye tracking experiments to investigate the online effects of these factors. In the experiments we looked at the influence of these factors on the process of establishing referential and relational coherence. Experiment 1 shows that immediate effects of causal relatedness on referential processing occur even with a connective that is not explicitly causal (when). Moreover, the results show that the early effect only occurs when readers expect a causal relation. Experiment 1 also shows that causal expectations facilitate the processing of causally related sentences. Experiment 2 shows that this is only the case when the content of the second clause actually allows a causal interpretation. The data show that causal expectations have differential effects on the processing of referential and relational coherence. Referential coherence is influenced proactively by the focusing of one of the referents in the context. Relational coherence, on the other hand, is influenced retroactively: only when there turns out to be a causal link between the sentences is processing facilitated by causal expectation.