Abstract
We report two experiments which tested whether cognitive capacities are limited to those functions that are computationally tractable (PTIME-Cognition Hypothesis). In particular, we investigated the semantic processing of reciprocal sentences with generalized quantifiers, i.e., sentences of the form Q dots are directly connected to each other, where Q stands for a generalized quantifier, e.g. all or most. Sentences of this type are notoriously ambiguous and it has been claimed in the semantic literature that the logically strongest reading is preferred (Strongest Meaning Hypothesis). Depending on the quantifier, the verification of their strongest interpretations is computationally intractable whereas the verification of the weaker readings is tractable. We conducted a picture completion experiment and a picture verification experiment to investigate whether comprehenders shift from an intractable reading to a tractable reading which should be dispreferred according to the Strongest Meaning Hypothesis. The results from the picture completion experiment suggest that intractable readings occur in language comprehension. Their verification, however, rapidly exceeds cognitive capacities in case the verification problem cannot be solved using simple heuristics. In particular, we argue that during verification, guessing strategies are used to reduce computational complexity.
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Notes
A clarification may be in order: when we speak of intractable problems we always refer to NP-hard problems and tacitly assume that \(\mathsf{P}\ne \mathsf{NP}\) (for an introduction to computational complexity see Arora and Barak 2009).
There are different treatments of quantified reciprocals in the literature. Among others, Beck (2001) gave an analysis of reciprocals in terms of plural semantics (see also Langendoen 1978; Heim et al. 1991; Sternefeld 1998, among others). A clear advantage of Beck’s approach is that it is strictly compositional. Compositionality is, however, irrelevant for the present purpose because we are mainly interested in the truth conditions of complete sentences. Note that Beck’s account, for example, predicts truth conditions which are equivalent to the ones in (2).
More precisely, this is the case if there are at least two elements in the quantificational restriction. Dalrymple et al. (1998) stated this condition explicitly in their truth conditions. With upward entailing quantifiers this is, however, often irrelevant, because the quantificational antecedent requires a restriction of at least two elements—either because of its semantics or on pragmatic grounds.
Since complexity theory is concerned with the resource demands that are inherent to a computational problem, but independent of any concrete implementation, it is clearly concerned with Marr’s (1982) computational level.
Strictly speaking, the treatment effect of a factor with three levels corresponds to two fixed effects \(\beta _1,\, \beta _2\) and two random slopes \(S_{1s}, \,S_{2s}\). This will become clear in the discussion of the results below.
In fact, Szymanik (2010) even restricted \(Ram_S,\, Ram_I,\, Ram_W\) to upward entailing quantifiers.
The experiment included eight more conditions, i.e. reciprocal sentences with the antecedent most. Originally, we expected most to trigger the scalar implicature not all, which would have allowed us to compare it to all but one and exactly k. The results indicated that this was not the case, or rather, that the implicature could easily be canceled. In the false graph condition with four dots, for instance, we observed more than 60 % acceptance making it impossible to properly analyze most-reciprocals. We therefore decided not to report them in the present paper. For future research it would be interesting to test complex non-monotone quantifiers of the type most but not all which would obviously constitute excellent, albeit rather complex test cases for the PCH.
No interactions could be included into the random slopes of subjects because these models failed to converge. So, the model in (13) was the model with the maximal random effects structure that could be fitted.
References
Ajtai, M., & Fagin, R. (1990). Reachability is harder for directed than for undirected finite graphs. Journal of Symbolic Logic, 55(1), 113–150.
Arora, S., & Barak, B. (2009). Computational complexity: A modern approach. New York: Cambridge University Press.
Baayen, R. H., Davidson, D. J., & Bates, D. M. (2008). Mixed-effects modeling with crossed random effects for subjects and items. Journal of Memory and Language, 59, 390–412.
Baggio, G., & van Lambalgen, M. (2007). Processing consequences of the imperfective paradox. Journal of Semantics, 24(4), 307–330.
Barr, D. J., Levy, R., Scheepers, C., & Tily, H. J. (2013). Random effects structure for confirmatory hypothesis testing: Keep it maximal. Journal of Memory and Language., 68, 255–278.
Barton, G. E., Berwick, R. C., & Ristad, S. E. (1987). Computational complexity and natural language. Cambridge: MIT Press.
Beck, S. (2001). Reciprocals are definites. Natural Language Semantics, 9, 69–138.
Bott, O. (2010). The processing of events. Amsterdam: John Benjamins (Linguistics Today 162).
Bott, O., Schlotterbeck, F., & Szymanik, J. (2011). Interpreting tractable versus intractable reciprocal sentences. In J. Bos & S. Pulman (Eds.), Proceedings of the international conference on computational semantics (Vol. 9, pp. 75–84). Oxford: SIGSEM.
Cooper, G. F. (1990). The computational complexity of probabilistic inference using bayesian belief networks. Artificial Intelligence, 42(2), 393–405.
Dalrymple, M., Kanazawa, M., Kim, Y., McHombo, S., & Peters, S. (1998). Reciprocal expressions and the concept of reciprocity. Linguistics and Philosophy, 21(2), 159–210.
Frixione, M. (2001). Tractable competence. Minds and Machines, 11, 379–397.
Garey, M., & Johnson, D. (1979). Computers and intractability. San Francisco: W. H. Freeman and Co.
Gierasimczuk, N., & Szymanik, J. (2009). Branching quantification vs. two-way quantification. Journal of Semantics, 26(4), 329–366.
Hackl, M., Koster-Hale, J., & Varvoutis, J. (2012). Quantication and ACD: Evidence from real-time sentence processing. Journal of Semantics, 29, 145–206.
Heim, I., Lasnik, H., & May, R. (1991). Reciprocity and plurality. Linguistic Inquiry, 22(1), 63–101.
Hintikka, J. (1973). Quantifiers vs. quantification theory. Dialectica, 34(27), 329–358.
Isaac, A., Szymanik, J., & Verbrugge, R. (2013). Logic and complexity in cognitive science. In A. Baltag & S. Smets (Eds.), Johan van Benthem on logical and informational dynamics. Berlin: Springer (Trends in logic, outstanding contributions book series).
Jäger, F. T. (2008). Categorical data analysis: Away from ANOVAs (transformation or not) and towards logit mixed models. Journal of Memory and Language., 59, 434–446.
Joseph, D., & Planting, W. (1985). On the complexity of reachability and motion planning problems. In SCG ’85 Proceedings of the first annual symposium on computational geometry. New York: ACM Press.
Karp, R. M. (1972). Reducibility among combinatorial problems. In R. E. Miller & J. W. Thatcher (Eds.), Complexity of computer computations (pp. 85–103). New York: Plenum Press.
Keenan, E. (2006). Quantifiers: Semantics. In K. Brown (Ed.), Encyclopedia of language and Linguistics (2nd ed., Vol. 10, pp. 302–308). Oxford: Elsevier.
Kerem, N., Friedmann, N., & Winter, Y. (2010). Typicality effects and the logic of reciprocity. In Proceedings of SALT XIX.
Kirousis, L. M., & Kolaitis, P. G. (2001). On the complexity of model checking and inference in minimal models. In T. Eiter, W. Faber, & W. Truszczyski (Eds.), Logic programming and nonmonotonic reasoning: 6th international conference. Berlin: Springer (LNCS).
Kontinen, J., & Szymanik, J. (2008). A remark on collective quantification. Journal of Logic, Language and Information., 17(2), 131–140.
Langendoen, T. (1978). The logic of reciprocity. Linguistic Inquiry, 9(2), 177–197.
Lidz, J., Pietroski, P., Hunter, T., & Halberda, J. (2011). Interface transparency and the psychosemantics of ‘most’. Natural Language Semantics, 19(3), 227–256.
Marr, D. (1982). Vision: A computational investigation into the human representation and processing of visual information. San Francisco: W. H. Freeman and Co.
McMillan, C., Clark, R., Moore, P., Devita, C., & Grossman, M. (2006). Neural representation of generalized quantifier comprehension. Neuropsychologia, 43(12), 1729–1737.
Mostowski, M., & Szymanik, J. (2007). Computational complexity of some Ramsey quantifiers in finite models. The Bulletin of Symbolic Logic, 13, 281–282.
Mostowski, M., & Szymanik, J. (2012). Semantic bounds for everyday language. Semiotica, 188(1), 363–372.
Mostowski, M., & Wojtyniak, D. (2004). Computational complexity of the semantics of some natural language constructions. Annals of Pure and Applied Logic, 127(1–3), 219–227.
Peters, S., & Westerståhl, D. (2006). Quantifiers in language and Logic. Oxford: Clarendon Press.
Pietroski, P., Lidz, J., Hunter, T., & Halberda, J. (2009). The meaning of ‘most’: Semantics, numerosity, and psychology. Mind & Language, 24(5), 554–585.
Pratt-Hartmann, I. (2004). Fragments of language. Journal of Logic, Language and Information, 13(2), 207–223.
Pratt-Hartmann, I. (2009). On the computational complexity of the numerically definite syllogistic and related logics. Bulletin of Symbolic Logic, 14(1), 1–28.
Pratt-Hartmann, I. (2010). Computational complexity in natural language. In A. Clark, C. Fox, & S. Lappin (Eds.), The handbook of computational Linguistics and natural language processing. Hoboken: Wiley-Blackwell.
Pratt-Hartmann, I., & Third, A. (2006). More fragments of language. Notre Dame Journal of Formal Logic, 47(2), 151–177.
Pylkkänen, L., Brennan, J., & Bemis, D. K. (2011). Grounding the cognitive Neuroscience of semantics in linguistic theory. Language and Cognitive Processes, 26(9), 1317–1337.
Reif, J. (1987). Complexity of the generalized movers problem. In J. T. Schwartz, M. Sharir, & J. E. Hopcroft (Eds.), Planning, geometry, and complexity of robot motion. Norwood: Ablex Publishing.
Ristad, E. S. (1993). The language complexity game. Cambridge: MIT Press.
Sevenster, M. (2006). Branches of imperfect information: Logic, games, and computation. Ph.D. thesis, University of Amsterdam.
Steinert-Threlkeld, S., & Icard, I. I. I. (2013). Iterating semantic automata. Linguistics and Philosophy, 36(2), 151–173.
Sternefeld, W. (1998). Reciprocity and cumulative predication. Journal of Semantics, 36, 303–336.
Szymanik, J. (2009). Quantifiers in TIME and SPACE: Computational complexity of generalized quantifiers in natural language. Ph.D. thesis, University of Amsterdam.
Szymanik, J. (2010). Computational complexity of polyadic lifts of generalized quantifiers in natural language. Linguistics and Philosophy, 33(3), 215–250.
Szymanik, J., & Zajenkowski, M. (2010). Comprehension of simple quantifiers. Empirical evaluation of a computational model. Cognitive Science, 34(3), 521–532.
Szymanik, J., Steinert-Threlkeld, S., Zajenkowski, M., & Icard, T. (2013). Automata and complexity in multiple-quantifier sentence verification. In R. West & T. Stewart (Eds.), Proceedings of the 12th international conference on cognitive modeling. Ottawa: Carleton University.
Szymanik, J., & Zajenkowski, M. (2011). Contribution of working memory in the parity and proportional judgments. Belgian Journal of Linguistics, 25, 189–206.
Thorne, C. (2012). Studying the distribution of fragments of English using deep semantic annotation. In Proceedings of the ISA8 workshop.
Tomaszewicz, B. (2013). Quantifiers and visual cognition: The processing of proportional and superlative ‘most’ in Bulgarian and Polish. In J. Szymanik & R. Verbrugge (Eds.), Journal of Language, Logic and Information (this issue).
van Benthem, J. (1986). Essays in logical semantics. Dordrecht: Reidel (Studies in Linguistics and Philosophy 29).
van Rooij, I. (2008). The tractable cognition hypothesis. Cognitive Science, 32, 939–984.
van Rooij, I., Kwisthout, J., Blokpoel, M., Szymanik, J., & Toni, T. W. I. (2011). Intentional communication: Computationally easy or difficult? Frontiers in Human Neuroscience, 5(52), 1–18.
Veale, T., & Keane, M. T. (1997). The competence of suboptimal theories of structure mapping on hard analogies. In Proceeding of the 1997 international joint conference on artificial intelligence.
Wareham, T. (1999). Systematic parameterized complexity analysis in computational Phonology. Ph.D. thesis, University of Victoria.
Zajenkowski, M., Styła, R., & Szymanik, J. (2011). A computational approach to quantifiers as an explanation for some language impairments in schizophrenia. Journal of Communication Disorder, 44, 595–600.
Acknowledgments
This research was funded by the German Research Foundation in the Project B1 Incrementality of Semantic Interpretation of the Collaborative Research Center 833 The Construction of Meaning. The authors would like to thank Fritz Hamm, Nina Gierasimczuk, Janina Radó, Iris van Rooij, Wolfgang Sternefeld, Jakub Szymanik, Rineke Verbrugge and two anonymous reviewers for valuable comments and discussions on earlier drafts of the paper. We would also like to thank our reviewers and audiences at the International Workshop on Computational Semantics 9, the International Conference on Linguistic Evidence 2012 and the ESSLI workshop on Logic and Cognition where we have presented parts of the present work and work closely related to this paper. For their assistance in data collection and preparation of the experimental materials we would like to thank Anna Pryslopska and Aysenur Sarcan. Last but not least, we would like to thank Udo Klein for distributing questionnaires in one of his introductory courses.
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Schlotterbeck, F., Bott, O. Easy Solutions for a Hard Problem? The Computational Complexity of Reciprocals with Quantificational Antecedents. J of Log Lang and Inf 22, 363–390 (2013). https://doi.org/10.1007/s10849-013-9181-9
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DOI: https://doi.org/10.1007/s10849-013-9181-9