Accounting for Cross-Linguistic Variation: A Constraint-Based Perspective
R. Thornton, M. Gil, and M. C. MacDonald (1998).
In D. Hillert (Ed.) Syntax and Semantics, vol. 28: Sentence Processing: A Cross-Linguistic Perspective (pp. 211-225).

Much of the research on sentence processing has focused on discovering universal principles to explain parsing preferences. Recent cross-linguistic work, however, suggests that processing is sensitive to distributional information about individual languages. Along these lines, we explore a constraint-based approach to processing, in which cross-linguistic variation is explained by the interaction of language specific grammatical constraints with more general pragmatic principles. Specifically, we examine the role of pragmatic information in constraining the modification of complex noun phrases in English and Spanish. We first present data suggesting that, for both languages, initial comprehension is constrained in the same manner by pragmatic information. We then pursue an explanation of cross-linguistic differences in terms of pragmatic constraints on grammatical differences between the languages.

Pragmatic Constraint on the Interpretation of Complex Noun Phrases in Spanish and English
R. Thornton, M. C. MacDonald, and M. Gil (1999).
Journal of Experimental Psychology: Learning, Memory, and Cognition, 25, 1347-1365.

Four experiments examined the role of a pragmatic constraint, the modifiability of noun phrases (NPs), in the modification of complex NPs. Experiment 1 demonstrated that NPs that had received relatively specific prior modification were less likely to take additional modification than NPs with less specific modification. This effect obtained in both Spanish and English using two off-line tasks. Experiments 2 and 3 demonstrated on-line modifiability effects for both languages using a self-paced reading task. The results further suggested that although Spanish and English speakers may have opposing modification preferences, modifiability constrained their interpretations in the same direction. The results of Experiment 4 suggested that discrepancies between the off-line results from Experiment 1 and the on-line results from Experiment 3 may owe to task differences. Implications are discussed in relation to current models of sentence processing.

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The Concomitant Effects of Phrase Length and Informational Content in Sentence Comprehension
R. Thornton, M. C. MacDonald, and J. E. Arnold (2000).
Journal of Psycholinguistic Research, 29, 195-203. .

Recent evidence suggests that phrase length plays a crucial role in modification ambiguities. Using a self-paced reading task, we extended these results by examining the additional pragmatic effects that length manipulations may exert. The results demonstrate that length not only modulates modification preferences directly, but that it also necessarily changes the informational content of a sentence, which itself affects modification preferences. Our findings suggest that the same length manipulation affects multiple sources of constraints, both structural and pragmatic, which can each exert differing effects on processing.

Plausibility and Grammatical Agreement
R. Thornton, and M. C. MacDonald (2003).
Journal of Memory and Language, 48, 740-759.

Three experiments examined plausibility effects on the production and comprehension of subject-verb agreement. In a production task, participants were given a verb and sentence preamble and asked to create a complete passive sentence. The preambles contained two nouns (e.g., the album by the classical composers). The plausibility of the verb was manipulated so that either (a) both nouns could be plausible passive subjects (e.g., praised, as both albums and composers can plausibly be praised) or (b) only the head noun could be a plausible subject (e.g., played, as only albums can plausibly be played). The comprehension task was self-paced reading with the same materials. The results from both methodologies demonstrated robust plausibility effects. There were higher agreement error rates in production and longer RTs at the verb in comprehension when both nouns were plausible subjects than when only the head was plausible. Implications for current production models are considered and an alternative account is presented that is motivated by current comprehension models and other recent production data.

Language Comprehension and Production in Normal Aging
R. Thornton, & L. L. Light (2006).
In J.E. Birren & K.W. Schaie (Eds.) Handbook of the Psychology of Aging (6th ed.). San Diego, CA: Elsevier.

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When Language Comprehension Reflects Production Constraints: Resolving Ambiguities with the Help of Past Experience
M. C. MacDonald, and R. Thornton (Manuscript submitted for publication).

People strongly prefer to interpret sentences like John said that Mary left yesterday to mean that yesterday modifies left not said. This tendency has generally been attributed to inherent biases in the language comprehension system. An alternative view is pursued, that the comprehension biases emerge from different interpretation frequencies in the language, which themselves emerge from pressures on the language production system to place short phrases before long ones in sentences of this type. A small corpus analysis showed clear differences in productions as a function of phrase length, and two comprehension experiments examined interpretation patterns as a function of phrase length. Results demonstrated a local modification preference only in a long phrase condition, not in a short one. These results support claims that production pressures cause distributional regularities in the language, which are learned and exploited by comprehenders encountering new input.