The source ambiguity problem: Distinguishing the effects of grammar and processing on acceptability judgments

Abstract

Judgments of linguistic unacceptability may theoretically arise from either grammatical deviance or significant processing difficulty. Acceptability data are thus naturally ambiguous in theories that explicitly distinguish formal and functional constraints. Here, we consider this source ambiguity problem in the context of Superiority effects: the dispreference for ordering a wh-phrase in front of a syntactically “superior” wh-phrase in multiple wh-questions, e.g., What did who buy? More specifically, we consider the acceptability contrast between such examples and so-called D-linked examples, e.g., Which toys did which parents buy? Evidence from acceptability and self-paced reading experiments demonstrates that (i) judgments and processing times for Superiority violations vary in parallel, as determined by the kind of wh-phrases they contain, (ii) judgments increase with exposure, while processing times decrease, (iii) reading times are highly predictive of acceptability judgments for the same items, and (iv) the effects of the complexity of the wh-phrases combine in both acceptability judgments and reading times. This evidence supports the conclusion that D-linking effects are likely reducible to independently motivated cognitive mechanisms whose effects emerge in a wide range of sentence contexts. This in turn suggests that Superiority effects, in general, may owe their character to differential processing difficulty.

Keywords:

• Processing difficulty
• Grammatical constraints
• Acceptability judgments
• Superiority

Acknowledgments

For helpful discussion and input on this research, we thank Bruno Estigarribia, Evelina Fedorenko, Ted Gibson, Jeanette Pettibone, Laura Staum Casasanto, and Tom Wasow. Very special thanks go to Ted Gibson and Ev Fedorenko for running the participants from Experiment III at MIT's Tedlab, and to David Kettler for his help in conducting Experiment IV. For editorial assistance, we thank Camber Hansen-Karr. This first author gratefully acknowledges research support from NIH Training Grant T32-DC000041 via the Center for Research in Language at UC–San Diego.