Maryellen C. MacDonald

The lexical nature of syntactic ambiguity resolution.

: Ambiguity resolution is a central problem in language comprehension. Lexical and syntactic ambiguities are standardly assumed to involve different types of knowledge representations and be resolved by different mechanisms. An alternative account is provided in which both types of ambiguity derive from aspects of lexical representation and are resolved by the same processing mechanisms. Reinterpreting syntactic ambiguity resolution as a form of lexical ambiguity resolution obviates the need for special parsing principles to account for syntactic interpretation preferences, reconciles a number of apparently conflicting results concerning the roles of lexical and contextual information in sentence processing, explains differences among ambiguities in terms of ease of resolution, and provides a more unified account of language comprehension than was previously available.

Probabilistic constraints and syntactic ambiguity resolution

Abstract Natural languages contain probabilistic constraints that influence the resolution of ambiguities. Current models of sentence processing agree that probabilistic constraints affect syntactic ambiguity resolution, but there has been little investigation of the constraints themselves-what they are, how they differ in their effects on processing, and how they interact with one another. Three different types of probabilistic constraints were investigated: “pre-ambiguity” plausibility information, information about verb argument structure frequencies, and “post-ambiguity” constraints that arrive after the introduction of the ambiguity but prior to its disambiguation. Reading times for syntactically ambiguous sentences were compared to reading times for unambiguous controls in three self-paced reading experiments. All three kinds of constraints were found to be helpful, and when several constraints converged, ambiguity resolution was facilitated compared to when constraints conflicted. The importance of...

A Probabilistic Constraints Approach to Language Acquisition and Processing

This article provides an overview of a probabilistic constraints framework for thinking about language acquisition and processing. The generative approach attempts to characterize knowledge of language (i.e., competence grammar) and then asks how this knowledge is acquired and used. Our approach is performance oriented: the goal is to explain how people comprehend and produce utterances and how children acquire this skill. Use of language involves exploiting multiple probabilistic constraints over various types of linguistic and nonlinguistic information. Acquisition is the process of accumulating this information, which begins in infancy. The constraint satisfaction processes that are central to language use are the same as the bootstrapping processes that provide entry to language for the child. Framing questions about acquisition in terms of models of adult performance unifies the two topics under a set of common principles and has important consequences for arguments concerning language learnability.

Experience and sentence processing: statistical learning and relative clause comprehension.

Many explanations of the difficulties associated with interpreting object relative clauses appeal to the demands that object relatives make on working memory. MacDonald and Christiansen [MacDonald, M. C., & Christiansen, M. H. (2002). Reassessing working memory: Comment on Just and Carpenter (1992) and Waters and Caplan (1996). Psychological Review, 109, 35-54] pointed to variations in reading experience as a source of differences, arguing that the unique word order of object relatives makes their processing more difficult and more sensitive to the effects of previous experience than the processing of subject relatives. This hypothesis was tested in a large-scale study manipulating reading experiences of adults over several weeks. The group receiving relative clause experience increased reading speeds for object relatives more than for subject relatives, whereas a control experience group did not. The reading time data were compared to performance of a computational model given different amounts of experience. The results support claims for experience-based individual differences and an important role for statistical learning in sentence comprehension processes.

Verbal working memory and language production: Common approaches to the serial ordering of verbal information.

Verbal working memory (WM) tasks typically involve the language production architecture for recall; however, language production processes have had a minimal role in theorizing about WM. A framework for understanding verbal WM results is presented here. In this framework, domain-specific mechanisms for serial ordering in verbal WM are provided by the language production architecture, in which positional, lexical, and phonological similarity constraints are highly similar to those identified in the WM literature. These behavioral similarities are paralleled in computational modeling of serial ordering in both fields. The role of long-term learning in serial ordering performance is emphasized, in contrast to some models of verbal WM. Classic WM findings are discussed in terms of the language production architecture. The integration of principles from both fields illuminates the maintenance and ordering mechanisms for verbal information.

Linking Production and Comprehension Processes: The Case of Relative Clauses.

Six studies investigated the relationship between production and comprehension by examining how relative clause production mechanisms influence the probabilistic information used by comprehenders to understand these structures. Two production experiments show that accessibility-based mechanisms that are influenced by noun animacy and verb type shape relative clause production. Two corpus studies confirm these production mechanisms in naturally occurring productions. Two comprehension studies found that nouns and verb types occurring in structures that speakers do not produce are difficult to comprehend. Specifically, the probability of producing a passive structure for a verb type in a given animacy configuration, as measured in the production and corpus studies, predicts comprehension difficulty in active structures. Results suggest that the way in which the verb roles are typically mapped onto syntactic arguments in production plays a role in comprehension. Implications for the relationship between production, comprehension and language learning are discussed.

Resolution of quantifier scope ambiguities

Various processing principles have been suggested to be governing the resolution of quantifier scope ambiguities in sentences such as Every kid climbed a tree. This paper investigates structural principles, that is, those which refer to the syntactic or semantic positions of the quantified phrases. To test these principles, the preferred interpretations for three grammatical constructions were determined in a task in which participants made speeded judgments of whether a sentence following a doubly quantified sentence was a reasonable discourse continuation of the quantified sentence. The observed preferences cannot be explained by any single structural principle, but point instead to the interaction of several principles. Contrary to many proposals, there is little or no effect of a principle that assigns scope according to the linear order of the phrases. The interaction of principles suggests that alternative interpretations of the ambiguity may be initially considered in parallel, followed by selection of the single interpretation that best satisfies the principles. These results are discussed in relation to theories of ambiguity resolution at other levels of linguistic representation.

New and updated tests of print exposure and reading abilities in college students

The relationship between print exposure and measures of reading skill was examined in college students (N = 99, 58 female; mean age = 20.3 years). Print exposure was measured with several new self-reports of reading and writing habits, as well as updated versions of the Author Recognition Test and the Magazine Recognition Test (Stanovich & West, 1989). Participants completed a sentence comprehension task with syntactically complex sentences, and reading times and comprehension accuracy were measured. An additional measure of reading skill was provided by participants’ scores on the verbal portions of the ACT, a standardized achievement test. Higher levels of print exposure were associated with higher sentence processing abilities and superior verbal ACT performance. The relative merits of different print exposure assessments are discussed.

Conflicting cues and competition in subject-verb agreement

Traditional theories of agreement production assume that verb agreement is an essentially syntactic process. However, recent work shows that agreement is subject to a variety of influences both syntactic and non-syntactic, which raises the question of how these different sources of information are integrated during agreement production. We propose an account of agreement production in which several information sources contribute activation to singular and plural verb forms. Conflict between cues leads to competition which can in turn magnify the influence of subtle cues. Three fragment completion experiments tested key predictions of this constraint satisfaction approach. Experiment 1 demonstrated competition effects on verb choice and sentence initiation latencies. Experiments 2 and 3 demonstrated that conflicts between semantic and grammatical cues allow morphological regularity to exert a small but detectable effect on agreement. These results suggest that the constraint-satisfaction framework may provide a productive approach for understanding agreement production.

Plausibility and grammatical agreement

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.