One thought on “Evidence of accurate logical reasoning in online sentence comprehension

  1. Thanks for a really interesting talk! I’d second Roger’s comment on your design being really neat!

    But I also wanted to follow up on Jesse’s question, and chime in with a few more comments on the role of having your target sentences involve the presupposition trigger ‘know’, which also bear on the question of just what is happening ‘automatically’ with regards to evaluating entailments in sentence comprehension more generally. Assuming a broadly Stalnakerian framework, where presuppositions pose constraints on the context such that whatever content is presupposed has to (at least by default) be entailed by the common ground (the worlds compatible with what counts as established in the discourse), what your stimuli involve is a variation in whether or not the presupposition of ‘know’ is met – in some cases it is, and in others it is not, based on the relation between the premise and the conclusion. When it is not, then that would seem to give rise to either accommodation (silently adding the presupposition to the common ground) or presupposition failure.

    There is by now a fairly extensive literature on presupposition processing, which by and large suggests that presuppositions are evaluated rapidly, and I would argue automatically (in the sense that comprehenders can’t help but deal with this as part of any engagement with linguistic input, regardless of task), based on reading time evidence (self-paced and eye tracking) as well as visual world studies. Much of these are on triggers other than factives like ‘know’, and there’s reason to worry about how comparable triggers are, but by and large, I think the processing picture is fairly uniform. See sections 2.1 and 2.4 of a recent handbook article of mine for brief summaries and various references. (pre-print available at; reference below). But even for ‘know’ specifically, there’s at least one self-paced reading study that shows immediate slow-downs when the context does not support the presupposition (I think there’ are variants both for simply failing to support vs. being inconsistent with, but the latter may be in other papers, I’d have to double check) , reported in Sonja Tiemann’s dissertation (and some related papers): (see pp. 69 and 80 for stimuli and results, respectively, though there may be some other relevant discussions elsewhere, too).

    Your data seems to add nicely to this literature, and again, with a very neat design and very natural texts (which is no small feat!). But on the ‘automatic entailment processing’ front, looking at your study in this context may add some more nuance, especially when relating it to the psychological reasoning-type literature: if presuppositions are linguistically encoded (granted not something everyone assumes!), and they are evaluated automatically, i.e., obligatorily and rapidly, then even just a simple reading task will compel the comprehender to assess whether the context entails the presupposition. On one level, this fully leaves in place your broader point, in that standard natural text comprehension DOES necessarily involve evaluation of entailments. But the nature of how this comes about may be quite a bit more different from say, assessing entailments in the Wason task than your discussion could be taken to suggest, as in the case of presupposition triggers, processing the linguistic material itself requires this assessment.

    None of this undermines your very nice findings, but seeing them in this context may shift the overall state of the discussion somewhat, I would think. The question of how the apparent facility, ease, and automaticity of dealing with entailments in assessing presuppositions relates to struggles with incorporating and utilizing entailments in reasoning remains just as pressing, in any case, but the nature of the comparison perhaps becomes slightly different.

    I’d be happy to hear your thoughts, and hope the pointers to the presupposition literature are helpful!

    Schwarz, Florian. 2019. Presuppositions, Projection, and Accommodation – Theoretical Issues and Experimental Approaches. In Chris Cummins & Napoleon Katsos (eds.), Handbook of Experimental Semantics and Pragmatics, 83–113. Oxford: Oxford University Press.

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