Presupposition Projection in Online Processing

Abstract

A central aspect of language comprehension is that hearers integrate incoming linguistic content both with the rest of the current sentence and the larger discourse context. Presuppositions crucially interact with both intra-and intersentential context in intricate ways, which makes their study especially useful in this regard. We present a series of experiments investigating the time-course of interpreting presuppositions in online comprehension and the impact that so-called presupposition projection has on this in cases where presuppositions appear in embedded environments. We find immediate delays in eye tracking reading times when the presupposition of German wieder ('again') is not supported by the context, but only for unembedded occurrences of wieder. Further evidence from a rating experiment and a stops-making-sense study supports our interpretation of this result to the effect that global presuppositions of embedded presupposition triggers are not immediately available in processing. A second reading time experiment explores the effects of embedding further by providing presuppositional support in different locations in contexts with a more complex structure involving conditionals. We find longer reading times when the support is more distant, measured in terms of the number of projection steps posited by Discourse Representation Theory (DRT). Altogether, the results suggest that presupposition projection is a cognitively effortful process, and are thus consistent with theoretical accounts that reflect this in terms of the complexity of the representations involved in the different types of contexts, while other accounts that are more neutral in this regard need to be supplemented by additional assumptions or alternative explanations for the observed effects. On the more general level of discourse processing models, these results suggest that there is even more structure relevant to cognitive processes at a level between the surface representation and the purely semantic level (e.g., the commonly assumed level of a text-base) than previously assumed.

Presuppositions are Fast, whether Hard or Soft - Evidence from the visual world

“…While space constraints prevent me from presenting a detailed statistical analysis, the most crucial finding is that there is a significant interaction in the ambiguous time-window (β = 2.28, SE = 1.26, t = 1.82; χ 2 = 5.67, p < .05), which seems to be due to the temporary difference in relation between control and critical conditions for affirmative and negated versions respectively. This preliminary finding then suggests that projection of the presupposition of stop is associated with a delay comparable to that reported by Schwarz & Tiemann (2012, 2013b for again. This, in turn, further supports the view that the equivalent finding of rapid availability of presupposed content of again and stop (in affirmative contexts) in the present studies does not come about in different ways, but rather does constitute evidence for the immediate presence of presupposed content (whether introduced by a hard or a soft trigger) once a trigger is encountered.…”

“…As already mentioned, there is further evidence for stop and again to behave in parallel ways under negation, which bears on the issue of whether their presuppositions might be entailed in affirmative cases, and furthermore whether they might differ from one another in that regard. Schwarz & Tiemann (2012, 2013b provide evidence from reading time studies on German wieder ('again') for a processing cost of presupposition projection under negation and in conditionals. In brief, detecting inconsistencies of the presupposition with the discourse context seems to take longer when the presupposition trigger is introduced in an embedded environment.…”

Experimental Work in Presupposition and Presupposition Projection

“…In a second study, presuppositional support for wieder in the consequent of conditionals is introduced in varying locations, namely in the antecedent or in a context sentence. Schwarz & Tiemann (2015) interpret the results from this study as suggesting that the hierarchical distance in terms of the projection search path assumed by DRT directly affects reading times on the critical region. Such an effect is less straightforward to derive on non-representational accounts (such as dynamic semantics).…”

“…A final set of studies relating to projection is concerned with the resolution of presuppositions in context, either intra-sententially or in the discourse context, and its time-course in processing. First, in two reading time studies using eye tracking, Schwarz & Tiemann (2015) find embedding of presupposition triggers to modulate processing effects. In the first study (already mentioned in section 2.3.2) immediate eye movement effects on the critical word are found when the context was inconsistent with the presupposition, but only when the trigger (German wieder, 'again') was outside of the scope of negation.…”

Experimental Perspectives on Presuppositions

“…There are two other recent studies on presupposition processing that are not directly relevant to the question posed here(Schwarz and Tiemann 2013a, 2013b. Schwarz and Tiemann look at whether the position of the trigger in a complex sentence influences the processing of presuppositions.…”