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.     

韵律特征研究

介绍从知觉、认知和语料库分析角度对汉语韵律特征进行的一系列研究。（1）韵律特征知觉：用实验心理学和知觉标注的语料库分析方法,研究汉语语调和音高下倾与降阶问题,语句和语篇中知觉可以区分的韵律层级及相关的声学线索。研究结果支持汉语语调的双线模型理论和语句音高下倾的存在;证明语篇中知觉可以区分的韵律边界是小句、句子和段落,及其知觉相关的声学线索。（2）韵律特征与其他语言学结构的关系：在标注的语料库的基础上,用常规统计方法研究语句常规重音分布规律、语篇信息结构与重音的关系、并用决策树方法研究根据文本信息确定韵律短语边界和焦点的规则。（3）韵律特征在语篇理解中的作用：用实验心理学方法和脑电指标研究韵律对语篇信息整合和指代理解的影响,揭示其作用的认知和神经机制。讨论了这些研究结果对语音工程、语音学理论和心理语言学研究的实践和理论意义     

Utilization of Prosodic Information in Syntactic Ambiguity Resolution

Two self paced listening experiments examined the role of prosodic phrasing in syntactic ambiguity resolution. In Experiment 1, the stimuli consisted of early closure sentences (e.g., “While the parents watched, the child sang a song.”) containing transitive-biased subordinate verbs paired with plausible direct objects or intransitive-biased subordinate verbs paired with implausible direct objects. Experiment 2 also contained early closure sentences with transitively and intransitive-biased subordinate verbs, but the subordinate verbs were always followed by plausible direct objects. In both experiments, there were two prosodic conditions. In the subject-biased prosodic condition, an intonational phrase boundary marked the clausal boundary following the subordinate verb. In the object-biased prosodic condition, the clause boundary was unmarked. The results indicate that lexical and prosodic cues interact at the subordinate verb and plausibility further affects processing at the ambiguous noun. Results are discussed with respect to models of the role of prosody in sentence comprehension.     

Linguistic rhythm guides parsing decisions in written sentence comprehension

Various recent studies attest that reading involves creating an implicit prosodic representation of the written text which may systematically affect the resolution of syntactic ambiguities in sentence comprehension. Research up to now suggests that implicit prosody itself depends on a partial syntactic analysis of the text, raising the question of whether implicit prosody contributes to the parsing process, or whether it merely interprets the syntactic analysis. The present reading experiments examine the influence of stress-based linguistic rhythm on the resolution of local lexical-syntactic ambiguities in German. Both speech production data from unprepared oral reading and eye-tracking results from silent reading demonstrate that readers favor syntactic analyses that allow for a prosodic representation in which stressed and unstressed syllables alternate rhythmically. The findings contribute evidence confirming immediate and guiding effects of linguistic rhythm on the earliest stages of syntactic parsing in reading.     

Prosodic influences on the resolution of temporary ambiguity during on-line sentence processing

We present three experiments designed to investigate the role of prosody during sentence processing. The first investigated the question of whether an utterance's prosodic contour influences its comprehension on-line. We spliced the beginning and end portions of direct object and embedded clause sentences and observed the consequent effects on comprehension using a dual-task procedure to measure processing load. Our second experiment sought to determine-whether the constituent structure of these sentences could be reliably predicted using prosodic information. We found that the duration and F₀ contour associated with the main-clause verb and the following NP reliably distinguished between the direct object and embedded clause constructions. In the final experiment, we manipulated the duration of the main-clause verb and found that subjects used this information to guide their initial parse during on-line sentence comprehension. The need for a model of sentence processing that addresses the use of prosodic information is discussed.The work reported in this paper was supported in part by NTH grant DC00494.     

Prosodic phrasing is central to language comprehension

Words, like musical notes, are grouped together into phrases by their rhythmic and durational properties as well as their tonal pitch. This 'prosodic phrasing' affects the understanding of sentences. Many processing studies of prosody have investigated sentences with a single, grammatically required prosodic boundary, which might be interpreted strictly locally, as a signal to end the current syntactic unit. Recent results suggest, however, that the global pattern of prosodic phrasing is what matters in sentence comprehension, not just the occurrence or size of a single local boundary. In this article we claim that the impact of prosodic boundaries depends on the other prosodic choices a speaker has made. We speculate that prosody serves to hold distinct linguistic representations together in memory.     

Pupillometry reveals processing load during spoken language comprehension

This study investigated processing effort by measuring peoples’ pupil diameter as they listened to sentences containing a temporary syntactic ambiguity. In the first experiment, we manipulated prosody. The results showed that when prosodic structure conflicted with syntactic structure, pupil diameter reliably increased. In the second experiment, we manipulated both prosody and visual context. The results showed that when visual context was consistent with the correct interpretation, prosody had very little effect on processing effort. However, when visual context was inconsistent with the correct interpretation, prosody had a large effect on processing effort. The interaction between visual context and prosody shows that visual context has an effect on online processing and that it can modulate the influence of linguistic sources of information, such as prosody. Pupillometry is a sensitive measure of processing effort during spoken language comprehension.     

Recognition memory for active and passive sentences

Data from three experiments are reported in which recognition memory for active and passive sentences is compared. The results consistently show no difference, a result taken to invalidate syntactic memory hypotheses (e.g., the kernel plus tag and markedness hypotheses) which assume that the stored representation of passive sentences is more complex than that of active sentences. Previous reports of superior recall of active sentences are attributed to a reconstructive bias. One form of propositional hypothesis and a verbatim hypothesis are consistent with the data.This research was supported by Grant MH 19859 from NIMH to the first author, and by Rutgers University Research Council grants to both authors.     

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.     

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.     

Lexically independent priming in online sentence comprehension

Two eye-tracking experiments investigated what happens when people read pairs of sentences that have the same syntactic structure. Previous experiments have shown priming in online sentence processing only when critical lexical material overlaps between the prime and the target sentence. In the current study, participants were asked to read sentences containing modifier—goal ambiguities. Half of the target sentences were preceded by sentences with the same structure, and half were preceded by sentences with a different structure. In Experiment 1, the prime—target pairs had the same main verb. In Experiment 2, the prime—target pairs had different main verbs. Facilitated target sentence processing was observed in both Experiments 1 and 2 when the target sentences were preceded by a prime sentence with the same syntactic structure. These results provide the first evidence of lexically independent, between-sentence structural priming in online sentence comprehension.     

Effect of ambiguity and lexical availability on syntactic and lexical production

Speakers only sometimes include the that in sentence complement structures like The coach knew (that) you missed practice. Six experiments tested the predictions concerning optional word mention of two general approaches to language production. One approach claims that language production processes choose syntactic structures that ease the task of creating sentences, so that words are spoken opportunistically, as they are selected for production. The second approach claims that a syntactic structure is chosen that is easiest to comprehend, so that optional words like that are used to avoid temporarily ambiguous, difficult-to-comprehend sentences. In all experiments, speakers did not consistently include optional words to circumvent a temporary ambiguity, but they did omit optional words (the complementizer that) when subsequent material was either repeated (within a sentence) or prompted with a recall cue. The results suggest that speakers choose syntactic structures to permit early mention of available material and not to circumvent disruptive temporary ambiguities.     

Priming prepositional phrase attachment: Evidence from eye-tracking and event-related potentials

Three syntactic-priming experiments investigated the effect of structurally similar or dissimilar prime sentences on the processing of target sentences, using eye tracking (Experiment 1) and event-related potentials (ERPs) (Experiments 2 and 3) All three experiments tested readers' response to sentences containing a temporary syntactic ambiguity. The ambiguity occurred because a prepositional phrase modifier (PP-modifier) could attach either to a preceding verb or to a preceding noun. Previous experiments have established that (a) noun-modifying expressions are harder to process than verb-modifying expressions (when test sentences are presented in isolation); and (b) for other kinds of sentences, processing a structurally similar prime sentence can facilitate processing a target sentence. The experiments reported here were designed to determine whether a structurally similar prime could facilitate processing of noun-attached modifiers and whether such facilitation reflected syntactic-structure-building or semantic processes. These findings have implications for accounts of structural priming during online comprehension and for accounts of syntactic representation and processing in comprehension.     

Evoked potentials and the study of sentence comprehension

Evoked brain potentials were used to monitor moment-by-moment decisions during language comprehension. Subjects read sentences containing temporary syntactic ambiguities for which one of the possible interpretations was semantically implausible. The N400 component of the evoked potential, which is sensitive to implausibility, was used to discover when during a sentence subjects made a decision about the ambiguity. The results demonstrate that readers try to interpret a syntactic ambiguity early in a sentence rather than waiting for disambiguating information. This introduces a new way to use brain activity to study sentence comprehension processes.     

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.     

Parsing strategies and discourse context

Two experiments investigated syntactic processing during comprehension of sentences presented either in isolation or in a discourse context. Comprehension of a range of different types of surface structurally ambiguous sentences was studied. To explain the interpretations generally given to the sentences processed in isolation, two parsing principles were proposed: Kimball's (1973) Right Association and Verb Dominance. When the ambiguous sentences were read in context, the interpretations computed were still determined by these structurally based principles, even when this meant that the meanings were at variance with the prior context. These results indicate that surface structure parsing of sentences proceeds in the same way whether sentences are processed alone or in context.This research was supported by a grant from the Australian Research Grants Scheme. I thank Linda Cupples for her help in conducting the experiments and in analyzing the data. I am indebted to Marilyn Ford for her critical comments on an earlier, version of the article. Thanks are also due to Dianne Bradley, Ken Forster, and Roger Wales for their helpful comments on the topic.     

Prosodic Effects in Minimal Attachment

This experiment explores the role of prosodic cues in resolving temporary morphosyntactic ambiguities in spoken language comprehension. Using a cross-modal naming task, we find that prosodic cues are as effective as overt lexical cues in controlling how the listener resolves attachment ambiguities. This suggests that prosodic factors can affect the early stages of parsing and interpretation.     

Difficulty processing temporary syntactic ambiguities in Lewy body spectrum disorder

While grammatical aspects of language are preserved, executive deficits are prominent in Lewy body spectrum disorder (LBSD), including Parkinson’s disease (PD), Parkinson’s dementia (PDD) and dementia with Lewy bodies (DLB). We examined executive control during sentence processing in LBSD by assessing temporary structural ambiguities. Using an on-line word detection procedure, patients heard sentences with a syntactic structure that has high-compatibility or low-compatibility with the main verb’s statistically preferred syntactic structure, and half of the sentences were lengthened strategically between the onset of the ambiguity and its resolution. We found selectively slowed processing of lengthened ambiguous sentences in the PDD/DLB subgroup. This correlated with impairments on measures of executive control. Regression analyses related the working memory deficit during ambiguous sentence processing to significant cortical thinning in frontal and parietal regions. These findings emphasize the role of prefrontal disease in the executive limitations that interfere with processing ambiguous sentences in LBSD.     

What can prosody tell a parser?

In this paper, I consider how a sentence processor might use specific prosodic cues at various points in the processing of particular sentences containing (at least temporary) syntactic ambiguity. In principle, the usefulness of prosodic information depends on what a given cluster of prosodic cues typically signifies, and on which syntactic options exist for a given string: in only some instances can prosodic information provide useful disambiguating information.This work was supported by Grant #DC-01409, a Research and Training Grant funded by the National Institute on Deafness and Other Communicative Disorders to the National Center for Neurogenic Communication Disorders, University of Arizona. I wish to thank Andrew Barss for very helpful comments on an earlier draft of this paper.