Experimental Comparisons of Presuppositions and Implicatures

Abstract:
A core tenet in the theoretical study of linguistic meaning is that the overall meaning conveyed by an utterance is a conglomerate of different types of inferences, such as entailments, presuppositions, and implicatures. These are commonly assumed to differ, among other things, in their source (e.g., conventional vs. general reasoning) and status (e.g., defeasible or not). While the distinctions in this realm have been motivated by introspective judgments from the start, more systematic empirical evidence has only been brought into the picture more recently. Experimental investigations comparing different aspects of meaning promise to ground the relevant theoretical notions empirically and to refine, and potentially revise, the classification of expressions based on more fine-grained data. Furthermore, as more advanced experimental tools shed light on the time course of interpreting different aspects of meaning in real time, we come closer to understanding the actual cognitive processes involved in constructing the overall meaning of an utterance. This, in turn, places constraints on cognitively realistic accounts of how a given type of meaning arises.

This talk presents an overview of results from a number of experimental investigations comparing presuppositions and implicatures (as well as entailed content), which aim to assess recent theoretical proposals that analyze (certain) presupposition triggers as a type of implicature, in contrast to a more traditional view. A number of reaction time studies using a sentence-picture matching task with a 'Covered Box' (Huang et al. 2013) that we conducted has yielded comparable results for both cases, and thus are consistent with such unified proposals. In addition, they undermine the notion that reaction times based on implicature
responses are delayed. However, behavioral studies of children and Broca's aphasics provide support for the traditional distinction. Furthermore, initial results from recent and ongoing eye tracking studies extending the paradigm from our reaction time studies seem to point the same way, and also provide a new perspective on implicature processing. Taken together, the present set of studies supports the general approach of experimentally differentiating various aspects of meaning. But they also provide a reminder that caution is in order in interpreting experimental results, as not all measures necessarily reflect the underlying distinctions under consideration.