Teaching and Learning Guide for: Parallelism and Competition in Syntactic Ambiguity Resolution
Authors: Clifton Jr Charles , Staub Adrian 
Published: October 2009

This guide accompanies the following article: Charles Clifton Jr and Adrian Staub, ‘Parallelism and Competition in Syntactic Ambiguity Resolution’, Language and Linguistics Compass 2 (2008): 234–250, doi: 10.1111/j.1749‐818x.2008.00055.xIntroductionTwo metaphors have dominated cognitive psychology throughout its history: ‘activation’ and ‘computation’. Activation (itself metaphorically based on neural firing rate) assumes that representations (mental symbols or patterns of non‐symbolic ‘nodes’) exist at varying degrees of activation, and high activation of a representation amounts to something like perception or recall. Computation assumes that representations are instead constructed from more elementary components, and that a representation does not exist prior to its construction.We examine the differential implications of these metaphors in the domain of sentence comprehension. Most theories that claim the representation of a sentence is something that is activated by input which proposes that multiple representations are at least temporarily activated, and in order for one representation to be selected, it must de‐activate the others in a time‐consuming process of competition. Theories that claim that the representation of a sentence is constructed, in contrast, have to posit rules for how the input guides construction, but by and large, these theories do not claim that alternative possible representations compete with each other. We review evidence indicating that time‐consuming competition does exist in the process of recognizing individual words, but propose that nearly all existing evidence denies competition in the case of sentence comprehension.Annotated ReferencesClifton, C., Jr., A. Staub, and K. Rayner. 2007. Eye movements in reading words and sentences. Eye movement research: insights into mind and brain, ed. by. R. van Gompel, M. Fisher, W. Murray and R. L. Hill, 341–71. New York: Elsevier. doi:10.1016/B978‐008044980‐7/50017‐3This chapter contains an extensive review of experiments on eye movements made while reading sentences, examining a number of questions in addition to the one addressed here, namely, whether the eyes slow down while reading a syntactically ambiguous phrase.Duffy, S., G. Kambe, and K. Rayner. 2001. The effect of prior disambiguating context on the comprehension of ambiguous words: evidence from eye movements. On the consequences of meaning selection: perspectives on resolving lexical ambiguity, ed. by D. S. Gorfein, 27–43. Washington, DC: American Psychological Association. doi: 10.1037/10459‐002An accessible review of eyetracking research supporting the existence of competition between alternative meanings of ambiguous words.Elman, J. L., M. Hare, and K. McRae. 2004. Cues, constraints, and competition in sentence processing. Beyond nature‐nurture: essays in honor of Elizabeth Bates, ed. by M. Tomasello and D. Slobin, 111–138. Mahwah, NJ: Lawrence Erlbaum Associates.This chapter presents an implemented constraint‐based model of sentence comprehension, making a clear prediction that time‐consuming competition exists during the reading and the resolution of a syntactic ambiguity, and presenting data that indicate that reading is slowed only during the resolution.Frazier, L. 1987. Sentence processing: a tutorial review. Attention and performance XII, ed. by M. Coltheart, 559–86. Hillsdale, NJ: Lawrence Erlbaum Associates.This is probably the most‐cited presentation of the ‘garden‐path’ model discussed in the paper. It predates the full development of constraint‐based competition models.Frazier, L. (1995). Constraint satisfaction as a theory of sentence processing. Journal of Psycholinguistic Research 24.437–68. doi: 10.1007/BF02143161This article presents a variety of criticisms of constraint‐based models of sentence processing in addition to the current claim that competition in the region of a syntactic ambiguity is not observed.Green, M. J., and D. C. Mitchell. 2006. Absence of real evidence against competition during syntactic ambiguity resolution. Journal of Memory and Language 55.1–17. doi: 10.1016/j.jml.2006.03.003Green and Mitchell present an interesting claim that local ambiguity does not necessarily result in competition. The claim seems to be correct, but we argue that it does not plausibly apply to most instances of sentence comprehension.MacDonald, M. C., N. J. Pearlmutter, and M. S. Seidenberg. 1994. The lexical nature of syntactic ambiguity resolution. Psychological Review 101.676–703. doi: 10.1037/0033‐295X.101.4.676This is an important article, advocating the claim that sentence comprehension is much the same as word recognition, and that both are characterized by competition between multiple possible representations.van Gompel, R. P. G., M. J. Pickering, and M. J. Traxler, M. 2001. Reanalysis in sentence processing: evidence against current constraint‐based and two‐stage models. Journal of Memory and Language 45.225–258. doi: 10.1006/jmla.2001.2773One of a series of studies indicating that syntactic ambiguity can speed reading rather than slowing it.Focus Questions1. Assuming the authors’ perspective that there is parallel activation of, and competition between, multiple meanings of a word, but not between multiple syntactic analyses, why might this be the case? Are there considerations of efficiency or resource constraints that would give rise to this difference?2. In what other areas of cognition is there evidence of competition for selection between activated representations, or between response options?3. The authors suggest that the argument by Green and Mitchell (2006) is implausible because it assumes pre‐activation of all possible sentence continuations. Do you agree that this is implausible? Why or why not?4. In discussing Levy’s (2008) proposals, the authors raise the issue of whether processing behavior at the point of syntactic disambiguation is bimodal or unimodal. Why is this important? How could you tell if there is bimodality?5. Can you think of predictions made by an account of syntactic processing that assumes parallel activation of multiple alternatives, other than the ones discussed in the article?6. One possibility that is alluded to briefly in the article is that the reading time advantage obtained by van Gompel and colleagues for globally ambiguous sentences may be because of a failure to fully resolve the ambiguity. Do you know of any specific evidence suggestive of this? Can you think of critical experiments that might address this issue?Topical OutlineSyntactic parsing

Early Models: Heuristics, Delay
The Garden Path (GP) Model
Constraint‐Based Models
The State of the Art