Syntactic Ambiguity Resolution Research Articles

The role of working memory in syntactic ambiguity resolution: A psychometric approach.

In 2 studies, the authors used a combination of psychometric and experimental techniques to investigate the effects of domain-general and domain-specific working memory factors on offline decisions concerning attachment of an ambiguous relative clause. Both studies used English and Dutch stimuli presented to English- and Dutch-speaking participants, respectively. In Study 1, readers with low working memory spans were less likely to use recency strategies for disambiguation than were readers with high spans. This finding is inconsistent with predictions of locality- and resource-based accounts of attachment. Psychometric analyses showed that both domain-specific (verbal) and domain-general working memory accounted for the effect. Study 2 found support for the hypothesis that segmentation strategies imposed during silent reading can account for the counterintuitive relationship. Results suggest that readers with low spans have a greater tendency to break up large segments of text because of their limited working memory, leading to high attachment of the ambiguous relative clause.

Lexical mediation and context effects in sentence processing

Studies of syntactic ambiguity resolution have played a central role in resolving questions about when and how contextual information affects parsing processes. These investigations are often couched in terms of modularity versus interaction, with demonstrations of rapid contextual effects being taken as evidence that the mechanisms responsible for structuring sentences are permeable to referential or semantic context, and therefore non-modular. In this paper, we will propose that argument relations are constructed on the basis of lexically stored syntactic representations (as in MacDonald, M.C., Pearlmutter, N.J., and Seidenberg, M.S. (1994). Lexical nature of syntactic ambiguity resolution. Psychological Review, 101, 676–703. Pickering, M.J., and Traxler, M.J. (2004). Grammatical repetition and garden path effects. Paper presented to the CUNY Sentence Processing Conference. College Park, MD., Pickering, M.J., and Traxler, M.J. (2006). Syntactic Priming in Comprehension. Manuscript in preparation. Traxler, M.J., and Pickering, M.J. (2005, March). Syntactic priming in comprehension. Paper presented to the CUNY Sentence Processing Conference. Tucson, AZ), but that other types of structural decisions are made on the basis of general processing principles. This formulation can be tested by looking at how the parser reacts to immediate intra- and inter-sentential factors (short-term context) and how it reacts to patterns of input over longer time scales (long-term context). We begin with a brief review of work on context effects in syntactic disambiguation, sketch our account of parsing, and then provide evidence from two eye-tracking experiments that illustrate some of the processing principles that govern parsing of argument relations.

Syntactic ambiguity resolution and the prosodic foot: Cross-language differences

In this study we examined syntactic ambiguity resolution in two different Chinese languages, Cantonese and Mandarin, which are relatively similar grammatically but very different phonologically. We did this using four-character sentences that could be read using two, two-syllable sequences (2-2) or a structure where the first syllable could be read by itself. The results showed that when both potential readings were semantically congruent, Mandarin speakers had a strong preference for the 2-2 structure and they preferred that structure much more than Cantonese speakers did. We attribute this to Mandarin having a more dominant bisyllabic prosodic foot than Cantonese. When the 2-2 meaning was semantically incongruent, however, the alternative structure was preferred by both Mandarin and Cantonese speakers. Overall, the results suggest that, in silent reading tasks and semantically neutral conditions, the prosodic foot is generated automatically and can affect syntactic choices when ambiguity arises.

Relative clause attachment in Dutch: On-line comprehension corresponds to corpus frequencies when lexical variables are taken into account

Desmet, Brysbaert, and De Baecke (2002a) showed that the production of relative clauses following two potential attachment hosts (e.g., ‘Someone shot the servant of the actress who was on the balcony’) was influenced by the animacy of the first host. These results were important because they refuted evidence from Dutch against experience-based accounts of syntactic ambiguity resolution, such as the tuning hypothesis. However, Desmet et al. did not provide direct evidence in favour of tuning, because their study focused on production and did not include reading experiments. In the present paper this line of research was extended. A corpus analysis and an eye-tracking experiment revealed that when taking into account lexical properties of the NP host sites (i.e., animacy and concreteness) the frequency pattern and the on-line comprehension of the relative clause attachment ambiguity do correspond. The implications for exposure-based accounts of sentence processing are discussed.

Absence of real evidence against competition during syntactic ambiguity resolution

Using evidence from eye-tracking studies, Van Gompel, Pickering, Pearson, and Liversedge (2005) have argued against currently implemented constraint-based models of syntactic ambiguity resolution. The case against these competition models is based on a mismatch between reported patterns of reading data and the putative predictions of the models. Using a series of detailed simulations, we show that there are marked differences between the actual and claimed predictions of one of the main exemplar models. As a consequence, we argue that the existing data remain entirely compatible with at least one current constraint-based account. We end with a brief discussion of the implications for a range of other implemented models.

The interaction of top–down and bottom–up statistics in the resolution of syntactic category ambiguity

This paper investigates how people resolve syntactic category ambiguities when comprehending sentences. It is proposed that people combine: (a) context-dependent syntactic expectations (top–down statistical information) and (b) context-independent lexical-category frequencies of words (bottom–up statistical information) in order to resolve ambiguities in the lexical categories of words. Three self-paced reading experiments were conducted involving the ambiguous word “that” in different syntactic environments in order to test these and other hypotheses. The data support the top–down/bottom–up approach in which the relative frequencies of lexical entries for a word are tabulated independent of context. Data from other experiments from the literature are discussed with respect to the model proposed here.

Ambiguity Resolution Analysis in Incremental Parsing of Natural Language

Incremental parsing gains its importance in natural language processing and psycholinguistics because of its cognitive plausibility. Modeling the associated cognitive data structures, and their dynamics, can lead to a better understanding of the human parser. In earlier work, we have introduced a recursive neural network (RNN) capable of performing syntactic ambiguity resolution in incremental parsing. In this paper, we report a systematic analysis of the behavior of the network that allows us to gain important insights about the kind of information that is exploited to resolve different forms of ambiguity. In attachment ambiguities, in which a new phrase can be attached at more than one point in the syntactic left context, we found that learning from examples allows us to predict the location of the attachment point with high accuracy, while the discrimination amongst alternative syntactic structures with the same attachment point is slightly better than making a decision purely based on frequencies. We also introduce several new ideas to enhance the architectural design, obtaining significant improvements of prediction accuracy, up to 25% error reduction on the same dataset used in previous work. Finally, we report large scale experiments on the entire Wall Street Journal section of the Penn Treebank. The best prediction accuracy of the model on this large dataset is 87.6%, a relative error reduction larger than 50% compared to previous results.

Evidence against competition during syntactic ambiguity resolution

We report three eye-movement experiments that investigated whether alternative syntactic analyses compete during syntactic ambiguity resolution. Previous research ( Traxler, Pickering, & Clifton, 1998; Van Gompel, Pickering, & Traxler, 2001) has shown that globally ambiguous sentences are easier to process than disambiguated sentences, suggesting that competition does not explain processing difficulty. However, the disambiguation in these studies was delayed relative to the initial point of ambiguity, so they do not rule out models which claim that competition is very short-lasting. The current experiments show that globally ambiguous sentences are easier to process than disambiguated sentences even when the disambiguation is immediate. Furthermore, globally ambiguous sentences are no harder to process than syntactically unambiguous sentences. We argue that the results are inconsistent with currently implemented constraint-based competition models, and support variable-choice reanalysis models such as the unrestricted race model.

The Effect of Phonemic Repetition on Syntactic Ambiguity Resolution: Implications for Models of Working Memory

Two reading experiments investigated the extent to which the presence of phonemic repetition in sentences influenced processing difficulty during syntactic ambiguity resolution In both experiments, participants read sentences silently as reading time was measured Reading time on sentences containing a temporary syntactic ambiguity was compared to reading time on unambiguous control sentences. Sentences either did or did not contain repeated phonemes. The results showed that reading time was longer for sentences containing a syntactic ambiguity than for unambiguous control sentences. Reading time was also longer on sentences containing repeated phonemes than on sentences that did not contain repeated phonemes. Phonemic repetition did not increase the time taken for syntactic ambiguity resolution; rather, the effects of syntactic ambiguity and phonemic repetition were temporally distinct, with the effect of phonemic repetition following the effect of syntactic ambiguity. Implications for theories of working memory are discussed.

The On-Line Resolution of the Sentence Complement/Relative Clause Ambiguity: Evidence from Spanish

The On-Line Resolution of the Sentence Complement/Relative Clause Ambiguity: Evidence from Spanish

Actions and affordances in syntactic ambiguity resolution.

In 2 experiments, eye movements were monitored as participants followed instructions containing temporary syntactic ambiguities (e.g., "Pour the egg in the bowl over the flour"). The authors varied the affordances of task-relevant objects with respect to the action required by the instruction (e.g., whether 1 or both eggs in the visual workspace were in liquid form, allowing them to be poured). The number of candidate objects that could afford the action was found to determine whether listeners initially misinterpreted the ambiguous phrase ("in the bowl") as specifying a location. The findings indicate that syntactic decisions are guided by the listener's situation-specific evaluation of how to achieve the behavioral goal of an utterance.

The On-Line Resolution of the Sentence Complement/Relative Clause Ambiguity: Evidence from Spanish

Two self-paced reading experiments investigated syntactic ambiguity resolution in Spanish. The experiments examined the way in which Spanish subjects initially interpret sentences that are temporarily ambiguous between a sentence complement and a relative clause interpretation. Experiment 1 examined whether the sentence complement preference found in English is observed in Spanish speaking subjects. In Experiment 2, verbal mood was manipulated in order to study the influence of verb-specific information on sentence processing. Since subcategorization for a subjunctive complement clause is generally assumed to be a lexical property of some verbs, the manipulation of the mood of the embedded verb affords us an interesting and novel way to examine the influence of lexical information on syntactic ambiguity resolution. Experiment 1 showed that Spanish speakers initially interpret the ambiguous that-clause as a sentence complement. Experiment 2 showed that verb-specific information, in particular, the information that specificies that a verb subcategorizes for a subjunctive complement, is accessed and used rapidly and affects the ambiguity resolution process. The results are discussed in relation to current models of sentence processing.

The misinterpretation of noncanonical sentences

Research on language comprehension has focused on the resolution of syntactic ambiguities, and most studies have employed garden-path sentences to determine the system’s preferences and to assess its use of nonsyntactic sources information. A topic that has been neglected is how syntactically challenging but essentially unambiguous sentences are processed, including passives and object-clefts—sentences that require thematic roles to be assigned in an atypical order. The three experiments described here tested the idea that sentences are processed both algorithmically and heuristically. Sentences were presented aurally and the participants’ task was to identify the thematic roles in the sentence (e.g., Who was the do-er?). The first experiment demonstrates that passives are frequently and systematically misinterpreted, especially when they express implausible ideas. The second shows that the surface frequency of a syntactic form does not determine ease of processing, as active sentences and subject-clefts were comprehended equally easily despite the rareness of the latter type. The third experiment compares the processing of subject- and object-clefts, and the results show that they are similar to actives and passives, respectively, again despite the infrequent occurrence in English of any type of cleft. The results of the three experiments suggest that a comprehensive theory of language comprehension must assume that simple processing heuristics are used during processing in addition to (and perhaps sometimes instead of) syntactic algorithms. Moreover, the experiments support the idea that language processing is often based on shallow processing, yielding a merely “good enough” rather than a detailed linguistic representation of an utterance’s meaning.

Studying the grammatical aspects of word recognition: lexical priming, parsing, and syntactic ambiguity resolution.

Two experiments are reported examining the relationship between lexical and syntactic processing during language comprehension, combining techniques common to the on-line study of syntactic ambiguity resolution with priming techniques common to the study of lexical processing. By manipulating grammatical properties of lexical primes, we explore how lexically based knowledge is activated and guides combinatory sentence processing. Particularly, we find that nouns (like verbs, see Trueswell & Kim, 1998) can activate detailed lexically specific syntactic information and that these representations guide the resolution of relevant syntactic ambiguities pertaining to verb argument structure. These findings suggest that certain principles of knowledge representation common to theories of lexical knowledge--such as overlapping and distributed representations--also characterize grammatical knowledge. Additionally, observations from an auditory comprehension study suggest similar conclusions about the lexical nature of parsing in spoken language comprehension. They also suggest that thematic role and syntactic preferences are activated during word recognition and that both influence combinatory processing.

Eye movements and spoken language comprehension: Effects of visual context on syntactic ambiguity resolution

When participants follow spoken instructions to pick up and move objects in a visual workspace, their eye movements to the objects are closely time-locked to referential expressions in the instructions. Two experiments used this methodology to investigate the processing of the temporary ambiguities that arise because spoken language unfolds over time. Experiment 1 examined the processing of sentences with a temporarily ambiguous prepositional phrase (e.g., “Put the apple on the towel in the box”) using visual contexts that supported either the normally preferred initial interpretation (the apple should be put on the towel) or the less-preferred interpretation (the apple is already on the towel and should be put in the box). Eye movement patterns clearly established that the initial interpretation of the ambiguous phrase was the one consistent with the context. Experiment 2 replicated these results using prerecorded digitized speech to eliminate any possibility of prosodic differences across conditions or experimenter demand. Overall, the findings are consistent with a broad theoretical framework in which real-time language comprehension immediately takes into account a rich array of relevant nonlinguistic context.

Invoking Discourse-Based Contrast Sets and Resolving Syntactic Ambiguities

Four self-paced reading experiments focusing on the main clause/reduced relative clause ambiguity were conducted to assess the effects of semantic focus on the resolution of syntactic ambiguities. Experiment 1 showed that the presence of the focus operator only resulted in diminished garden path effects for reduced relative clauses, controlling for definiteness of the noun phrase. Experiment 2 manipulated discourse contexts and showed that the presence of an explicit contrast set in the context sentence preceding a target sentence with focus interacted with the continuation of an ambiguous fragment as either a main clause or reduced relative. Experiment 3 showed that discourse context effects did not play a role in reading times when the target sentence did not contain a focus marker, confirming that the focus effect is the result of the joint interaction of a focus marker and discourse context. The results of Experiment 4 suggested that the semantic requirements of focus combined with a constraining discourse lead to a garden path effect with main clause continuations of ambiguous strings as compared to unambiguous strings. These results provide evidence against a garden path model of sentence processing which initially computes only a single analysis. Possible mechanisms underlying the identification of contrast sets in discourse are discussed.

Syntactic Ambiguity Resolution after Initial Misanalysis: The Role of Recency

Although a great deal of research has investigated the factors affecting initial syntactic processing, little is known about the factors that affect processing during reanalysis. To address this question, we report a self-paced reading and an eye-tracking experiment which tested sentences in which there is initially more than one way for reanalysis to proceed, but where this choice is eventually disambiguated by a gender-marked reflexive (like The photographers found the countess who heard the choirboy had really enjoyed himself/herself at the concert in the town hall). The experiments provide evidence that the human sentence processing mechanism obeys a recency preference in reanalysis. This suggests that at least some of the factors guiding reanalysis are similar to those guiding initial analysis.

La levée des ambiguïtés syntaxiques : apport des recherches interlangues

Summary : Resolution of syntactic ambiguities : Evidence from cross-linguistic studies. Determining how people convert a string of words into a representation of the structure of the sentence is a central problem in sentence processing. Studying how people handle syntactic ambiguities offers much of the information needed to tackle important issues in parsing. The first section of this article presents three types of models as a function of the solutions they propose in case of syntactic ambiguity : 1/ the parser forces the decision (e.g., in favour of the simplest structure) ; 2/ the choice is postponed until more information is available ; 3/ the different structures are processed in parallel, together with other sources of information. The second section shows that these models cannot explain cross-linguistic differences observed in the resolution of syntactically ambiguous sentences. The third section presents a few new models that have been proposed to explain cross-linguistic data. This review shows how cross-linguistic findings raise major difficulties for models that have been presented so far in the literature. Key words : syntactic ambiguity, sentence comprehension, relative clause.

Prosodic Facilitation in the Resolution of Syntactic Ambiguities in Subjects with Left and Right Hemisphere Damage

The purpose of this study was to determine if prosody facilitates the comprehension of sentences containing temporary syntactic ambiguities in control, and left (LHD) and right hemisphere damaged (RHD) subjects. To test for effects of prosodic facilitation, sentences were created where prosodic boundaries coincided with (cooperating), were absent (baseline), or conflicted (conflicting) with syntactic boundaries in three response times (RTs) experiments. Despite differences in overall RTs and response accuracy for each group, all three groups responded faster and more accurately to sentences in the cooperating than in the baseline and conflicting conditions across experiments, indicating that prosody facilitates syntactic parsing in brain-damaged subjects just as it does with normal control subjects. Results are discussed in relation to psycholinguistic theories of syntactic parsing and neurolinguistic theories of hemispheric specialization in processing the acoustic properties of prosodic structures.

The Effects of Thematic Fit and Discourse Context on Syntactic Ambiguity Resolution

Three experiments were conducted to assess the impact of the thematic fit and discourse context on the processing of sentences that were initially syntactically ambiguous between main verb and reduced relative constructions. Specifically, we tested a strong version of a constraint satisfaction position that suggests that thematic fit and context should produce a garden path effect on a simple, main verb construction. Across three experiments we observed garden path effects for reduced relative target sentences in first-pass reading-time measures, but similar effects for main verb sentences did not occur despite the thematic fit information and discourse contexts which were biased toward the reduced relative reading. The pattern of results is consistent with the predictions of the garden path theory.