Prosodic disambiguation of syntactic structure: for the speaker or for the addressee?

Evidence has been mixed on whether speakers spontaneously and reliably produce prosodic cues that resolve syntactic ambiguities. And when speakers do produce such cues, it is unclear whether they do so "for" their addressees (the audience design hypothesis) or "for" themselves, as a by-product of planning and articulating utterances. Three experiments addressed these issues. In Experiments 1 and 3, speakers followed pictorial guides to spontaneously instruct addressees to move objects. Critical instructions (e.g., "Put the dog in the basket on the star") were syntactically ambiguous, and the referential situation supported either one or both interpretations. Speakers reliably produced disambiguating cues to syntactic ambiguity whether the situation was ambiguous or not. However, Experiment 2 suggested that most speakers were not yet aware of whether the situation was ambiguous by the time they began to speak, and so adapting to addressees' particular needs may not have been feasible in Experiment 1. Experiment 3 examined individual speakers' awareness of situational ambiguity and the extent to which they signaled structure, with or without addressees present. Speakers tended to produce prosodic cues to syntactic boundaries regardless of their addressees' needs in particular situations. Such cues did prove helpful to addressees, who correctly interpreted speakers' instructions virtually all the time. In fact, even when speakers produced syntactically ambiguous utterances in situations that supported both interpretations, eye-tracking data showed that 40% of the time addressees did not even consider the non-intended objects. We discuss the standards needed for a convincing test of the audience design hypothesis.     

The influence of prosodic structure on the resolution of temporary syntactic closure ambiguities

This paper investigates the influence of prosodic structure on the process of sentence comprehension, with a specific focus on the relative contributions of syntactic and prosodic information to the resolution of temporary syntactic closure ambiguities. We argue that prosodic structure provides an initial memory representation for spoken sentences, and that information from this prosodic representation is available to inform syntactic parsing decisions. This view makes three predictions for the processing of temporary syntactic ambiguity: 1. When prosodic and syntactic boundaries coincide, syntactic processing should be facilitated. 2. When prosodic boundaries are placed at misleading points in syntactic structure, syntactic processing should show interference effects. 3. The processing difficulties that have been reliably demonstrated in reading experiments for syntactically complex sentences should disappear when those sentences are presented with a felicitous prosodic structure in listening experiments. These predictions were confirmed by series of experiments measuring end-of-sentence comprehension time and cross-modal naming time for sentences with temporary syntactic closure ambiguities. Sentences with coinciding or conflicting prosodic and syntactic boundaries were compared to a prosodic baseline condition.This research was supported in part by NIMH grant R29 MH51768 to the first author and NIMH grant T32 MH19729 to the Northeastern University Psychology Department.     

从讲话者和听话者两个角度看韵律的句法解歧

综述了近年来韵律句法解歧方面的一些研究。首先介绍了韵律特征及其作用;其次,简单介绍了句法歧义及其加工模型;然后从讲话者和听话者两个角度,分析了讲话者在自然的情境中是否自发稳定的生成韵律线索,以及听话者是否能够即时的使用韵律信息引导最初的句法分析两个问题,并简要地阐述了汉语韵律和句法的独特特点以及国内的相关研究;最后,初步探讨了进行汉语相应研究应该注意的问题     

Young children's use of prosody in sentence parsing

Korean children's ability to use prosodic phrasing in sentence comprehension was studied using two types of ambiguity. First, we examined a word-segmentation ambiguity in which placement of the phrasal boundary leads to different interpretations of a sentence. Next, we examined a syntactic ambiguity in which the same words were differently grouped into syntactic phrases by prosodic demarcation. Children aged 3 or 4 years showed that they could use prosodic information to segment utterances and to derive the meaning of ambiguous sentences when the sentences only contained a word-segmentation ambiguity. However, even 5- to 6-year-old children were not able to reliably resolve the second type of ambiguity, an ambiguity of phrasal grouping, by using prosodic information. The results demonstrate that children's difficulties in dealing with structural ambiguity are not due to their inability to use prosodic information.     

Prosody and parsing in coordination structures

The effect of prosodic boundary cues on the off-line disambiguation and on-line parsing of coordination structures was examined. It was found that relative clauses were attached to coordinated object noun phrases in preference to second conjuncts in sentences like: The lawyer greeted the powerful barrister and the wise judge who was/were walking to the courtroom. Naive speakers signalled the syntactic contrast between the two structures by a prosodic break between the conjuncts when the relative clause was attached to the second conjunct. Listeners were able to use this prosodic information in both off-line syntactic disambiguation and on-line syntactic parsing. The findings are compatible with a model in which prosody has a strong immediate effect on parsing. It is argued that the current experimental design has avoided confounds present in earlier studies on the on-line integration of prosodic and syntactic information.     

Untrained speakers' use of prosody in syntactic disambiguation and listeners' interpretations

We investigated how naively produced prosody affects listeners' end interpretations of ambiguous utterances. Non-professional speakers who were unaware of any ambiguity produced ambiguous sentences couched in short, unambiguous passages. In a forced-choice task, listeners could not tell which context the isolated ambiguous sentences came from (Exp. 1). However, listeners were able to correctly paraphrase the least ambiguous subset of these utterances, showing that prosody can be used to resolve ambiguity (Exp. 2). Nonetheless, in everyday language use, both prosody and context are available to interpret speech. When the least ambiguous sentences were cross-spliced into contexts biasing towards their original interpretations or into contexts biasing towards their alternative interpretations, answers to content questions about the ambiguous sentence, confidence ratings, and ratings of naturalness all indicated that prosody is ignored when context is available (Exp. 3). Although listeners can use prosody to interpret ambiguous sentences, they generally do not, and this makes sense in light of the frequent lack of reliable prosodic cues in everyday speech. Received: 3 April 1998 / Accepted: 21 October 1998     

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.     

Addressees' needs influence speakers' early syntactic choices

A current debate in psycholinguistics concerns how speakers take addressees' knowledge or needs into account during the packaging of utterances. In retelling stories, speakers are more likely to mention atypical instruments than easily inferrable, typical instruments; in a seminal study, Brown and Dell (1987) suggested that this is not an adjustment to addressees but is simply easiest for speakers. They concluded that manipulating addressees' knowledge did not affect speakers' mention of instruments. However, their addressees were confederates who heard the same stories repeatedly. We had speakers retell stories to naive addressees who either saw or did not see a picture illustrating the main action and instrument. When addressees lacked pictures, speakers were more likely to mention atypical instruments, to mention them early (within the same clause as the action verb), and to mark atypical instruments as indefinite. This suggests that with visual copresence, speakers can take addressees' knowledge into account in early syntactic choices.     

Experimentally disentangling what's beneficial about elderspeak from what's not

Three studies evaluated different varieties of elderspeak using a referential communication task. Experiment 1 compared the effects of syntactic simplifications and semantic elaborations. Experiment 2 contrasted syntactic simplifications and prosodic exaggerations. Experiment 3 contrasted 2 different syntactic simplification strategies and 2 different prosodic exaggerations. Providing semantic elaborations and reducing the use of subordinate and embedded clauses benefit older adults and improve their performance on the referential communication task, whereas reducing sentence length, slowing speaking rate, and using high pitch do not. The use of short sentences, a slow rate of speaking, and high pitch resulted in older adults' reporting more communication problems. These experiments validate a version of elderspeak that benefits older adults without sounding patronizing and insulting.     

Pre-schoolers use head gestures rather than prosodic cues to highlight important information in speech

Previous evidence suggests that children's mastery of prosodic modulations to signal the informational status of discourse referents emerges quite late in development. In the present study, we investigate the children's use of head gestures as it compares to prosodic cues to signal a referent as being contrastive relative to a set of possible alternatives. A group of French-speaking pre-schoolers were audio-visually recorded while playing in a semi-spontaneous but controlled production task, to elicit target words in the context of broad focus, contrastive focus, or corrective focus utterances. We analysed the acoustic features of the target words (syllable duration and word-level pitch range), as well as the head gesture features accompanying these target words (head gesture type, alignment patterns with speech). We found that children's production of head gestures, but not their use of either syllable duration or word-level pitch range, was affected by focus condition. Children mostly aligned head gestures with relevant speech units, especially when the target word was in phrase-final position. Moreover, the presence of a head gesture was linked to greater syllable duration patterns in all focus conditions. Our results show that (a) 4- and 5-year-old French-speaking children use head gestures rather than prosodic cues to mark the informational status of discourse referents, (b) the use of head gestures may gradually entrain the production of adult-like prosodic features, and that (c) head gestures with no referential relation with speech may serve a linguistic structuring function in communication, at least during language development.     

Sensitivity to prosodic structure in left- and right-hemisphere-damaged individuals

An experiment was conducted in order to determine whether left- (LHD) and right-hemisphere-damaged (RHD) patients exhibit sensitivity to prosodic information that is used in syntactic disambiguation. Following the work of, a cross-modal lexical decision task was performed by LHD and RHD subjects, as well as by adults without brain pathology (NC). Subjects listened to sentences with attachment ambiguities with either congruent or incongruent prosody, while performing a visual lexical decision task. Results showed that each of the unilaterally damaged populations differed from each other, as well as from the NCs in terms of sensitivity regarding prosodic cues. Specifically, the RHD group was insensitive to sentence prosody as a whole. This was in contrast to the LHD patients, who responded to the prosodic manipulation, but in the unexpected direction. Results are discussed in terms of current hypotheses regarding the hemispheric lateralization of prosodic cues.     

Understanding speaker attitudes from prosody by adults with Parkinson's disease

The ability to interpret vocal (prosodic) cues during social interactions can be disrupted by Parkinson's disease, with notable effects on how emotions are understood from speech. This study investigated whether PD patients who have emotional prosody deficits exhibit further difficulties decoding the attitude of a speaker from prosody. Vocally inflected but semantically nonsensical ‘pseudo‐utterances’ were presented to listener groups with and without PD in two separate rating tasks. Task 1 required participants to rate how confident a speaker sounded from their voice and Task 2 required listeners to rate how polite the speaker sounded for a comparable set of pseudo‐utterances. The results showed that PD patients were significantly less able than HC participants to use prosodic cues to differentiate intended levels of speaker confidence in speech, although the patients could accurately detect the polite/impolite attitude of the speaker from prosody in most cases. Our data suggest that many PD patients fail to use vocal cues to effectively infer a speaker's emotions as well as certain attitudes in speech such as confidence, consistent with the idea that the basal ganglia play a role in the meaningful processing of prosodic sequences in spoken language ( Pell & Leonard, 2003 ).     

Lexically-driven syntactic priming

Syntactic priming studies demonstrate that exposure to a particular syntactic structure leads speakers to reproduce the same structure in subsequent utterances. Explanations for this phenomenon rely on either the retrieval of morphosyntactic features associated with the verb in the prime sentence or the preservation of the mapping between message and word sequences in the prime sentence. Two experiments test the featural account of syntactic priming. We used single word primes to investigate the dative alternation in German (Experiment 1) and Dutch (Experiment 2). Native speakers read ditransitive verbs that are restricted either to the prepositional (dative) or double object construction, followed by pictures that can be described with either structure. We find that a single verb in isolation is sufficient to bias speakers' production preferences supporting lexically-driven accounts of syntactic priming.     

Do speakers avoid ambiguities during dialogue?

What affects speakers' production of ambiguous utterances in dialogue? They might consider ease of production for themselves, or ease of comprehension for their addressees. Previous research has demonstrated that ease of production plays a role in speakers' syntactic choices, but that ease of comprehension does not. However, such studies have not employed dialogues that involve role swapping on a turn-by-turn basis. In our experiment, participants alternated in giving and following instructions to move objects around on a grid. They tended to repeat the syntactic form just used by their interlocutor, reflecting sensitivity to ease of production. More interestingly, they were more likely to disambiguate their utterances when the visual context was potentially ambiguous than when it was not, reflecting sensitivity to ease of comprehension. We conclude that speakers pay attention to their beliefs about their addressees' ease of comprehension, in addition to considering ease of production for themselves.     

Constituent Length Affects Prosody and Processing for a Dative NP Ambiguity in Korean

Two sentence processing experiments on a dative NP ambiguity in Korean demonstrate effects of phrase length on overt and implicit prosody. Both experiments controlled non-prosodic length factors by using long versus short proper names that occurred before the syntactically critical material. Experiment 1 found that long phrases induce different prosodic phrasing than short phrases in a read-aloud task and change the preferred interpretation of globally ambiguous sentences. It also showed that speakers who have been told of the ambiguity can provide significantly different prosody for the two interpretations, for both lengths. Experiment 2 verified that prosodic patterns found in first-pass pronunciations predict self-paced reading patterns for silent reading. The results extend the coverage of the Implicit Prosody Hypothesis [Fodor, J Psycholinguist Res 27:285–319, 1998; Prosodic disambiguation in silent reading. In M. Hirotani (Ed.), NELS 32 (pp. 113–132). Amherst, MA: GLSA Publications, 2002] to another construction and to Korean. They further indicate that strong syntactic biases can have rapid effects on the formulation of implicit prosody.     

Fundamental frequency encoding of linguistic and emotional prosody by right hemisphere-damaged speakers.

To illuminate the nature of the right hemisphere's involvement in expressive prosodic functions, a story completion task was administered to matched groups of right hemisphere-damaged (RHD) and nonneurological control subjects. Utterances which simultaneously specified three prosodic distinctions (emphatic stress, sentence modality, emotional tone) were elicited from each subject group and then subjected to acoustic analysis to examine various fundamental frequency (F(0)) attributes of the stimuli. Results indicated that RHD speakers tended to produce F(0) patterns that resembled normal productions in overall shape, but with significantly less F(0) variation. The RHD patients were also less reliable than normal speakers at transmitting emphasis or emotional contrasts when judged from the listener's perspective. Examination of the results across a wide variety of stimulus types pointed to a deficit in successfully implementing continuous aspects of F(0) patterns following right hemisphere insult.     

Time-driven effects on parsing during reading

The phonological trace of perceived words starts fading away in short-term memory after a few seconds. Spoken utterances are usually 2-3 s long, possibly to allow the listener to parse the words into coherent prosodic phrases while they still have a clear representation. Results from this brain potential study suggest that even during silent reading, words are organized into 2-3 s long ‘implicit’ prosodic phrases. Participants read the same sentences word by word at different presentation rates. Clause-final words occurring at multiples of 2-3 s from sentence onset yielded increased positivity, irrespective of presentation rate. The effect was interpreted as a closure positive shift (CPS), reflecting insertion of implicit prosodic phrase boundaries every 2-3 s. Additionally, in participants with low working memory span, clauses over 3 s long produced a negativity, possibly indicating increased working memory load.     

晚期二语者句法加工过程的调节因素及其效应

针对晚期二语者句法加工能力的发展普遍存在困难这一现象, 近年来采用以ERP为核心技术的脑认知研究发现, 二语者的二语熟练度、一语和二语间具体的句法结构的相似程度、以及以工作记忆为核心的个体认知能力等因素起着各自独立而又相互影响的调节作用, 并且形成了浅层结构理论所主张的晚期二语者的句法加工与母语者有着本质差别的“定性说”与统一竞争模型所主张的晚期二语者和母语者在句法加工上没有本质差别的“量变说”两种理论分野, 二者的分歧集中表现为晚期二语者能否最终形成类母语水平的二语句法加工模式。为此, 需要开展以三个因素如何交互作用为主体的跨语言(二语与一语性质的多样性)研究。