Disfluencies and human language comprehension

Spoken language contains disfluencies, which include editing terms such as uh and um as well as repeats and corrections. In less than ten years the question of how disfluencies are handled by the human sentence comprehension system has gone from virtually ignored to a topic of major interest in computational linguistics and psycholinguistics. We discuss relevant empirical findings and describe a computational model that captures how disfluencies influence parsing and comprehension. The research reviewed shows that the parser, which presumably evolved to handle conversations, deals with disfluencies in a way that is efficient and linguistically principled. The success of this research program reinforces the current trend in cognitive science to view cognitive mechanisms as adaptations to real-world constraints and challenges.     

Expectation-based syntactic comprehension

This paper investigates the role of resource allocation as a source of processing difficulty in human sentence comprehension. The paper proposes a simple information-theoretic characterization of processing difficulty as the work incurred by resource reallocation during parallel, incremental, probabilistic disambiguation in sentence comprehension, and demonstrates its equivalence to the theory of Hale [Hale, J. (2001). A probabilistic Earley parser as a psycholinguistic model. In Proceedings of NAACL (Vol. 2, pp. 159-166)], in which the difficulty of a word is proportional to its surprisal (its negative log-probability) in the context within which it appears. This proposal subsumes and clarifies findings that high-constraint contexts can facilitate lexical processing, and connects these findings to well-known models of parallel constraint-based comprehension. In addition, the theory leads to a number of specific predictions about the role of expectation in syntactic comprehension, including the reversal of locality-based difficulty patterns in syntactically constrained contexts, and conditions under which increased ambiguity facilitates processing. The paper examines a range of established results bearing on these predictions, and shows that they are largely consistent with the surprisal theory.     

Persistent structural priming from language comprehension to language production

To examine the relationship between syntactic processes in language comprehension and language production, we compared structural persistence from sentence primes that speakers heard to persistence from primes that speakers produced. [Bock, J. K., & Griffin, Z. M. (2000). The persistence of structural priming: transient activation or implicit learning? Journal of Experimental Psychology: General, 129, 177-192.] showed that the production of target priming structures increased the probability of spontaneously using the same structures to describe events in subsequent pictures that were semantically unrelated to the primes. These priming effects persisted across as many as ten intervening filler trials. The present studies replicated these results using auditorily presented primes to which participants only listened. The results indicated persistence of priming across all lags, with relative magnitudes of priming as large as those observed by Bock and Griffin. The implication is that structural priming is persistent regardless of the modality in which language structures are experienced, underscoring the power of priming as an implicit learning mechanism.     

Embodied Cognition,affects and language comprehension

Phenomenology and the Cognitive Sciences - Our main considerations take as a starting point the educational policy demand for a model of competence of text comprehension, which should make it...     

The time-course of lexical and structural processes in sentence comprehension

Online sentence comprehension involves multiple types of cognitive processes: lexical processes such as lexical access, which call on the user's knowledge of the meaning of words in the language, and structural processes such as the integration of incoming words into an emerging representation. In this article, we investigate the temporal dynamics of lexical access and syntactic integration. Unlike much previous work that has relied on temporary ambiguity to investigate this question, we manipulate the frequency of the verb in unambiguous structures involving a well-studied syntactic complexity manipulation (subject- vs. object-extracted clefts). The results demonstrate that for high-frequency verbs, the difficulty of reading a more structurally complex object-extracted cleft structure relative to a less structurally complex subject-extracted cleft structure is largely experienced in the cleft region, whereas for low-frequency verbs this difficulty is largely experienced in the postcleft region. We interpret these results as evidence that some stages of structural processing follow lexical processing. Furthermore, we find evidence that structural processing may be delayed if lexical processing is costly, and that the delay is proportional to the difficulty of the lexical process. Implications of these results for contemporary accounts of sentence comprehension are discussed.     

Memory models and language comprehension

Abstract.— A schematic model for storage of meaningful verbal material is outlined. Storage of words and meaningful symbols is assumed to be separate. Accordingly it is argued that transformational grammar may be in error, and that the recent distinction between thinking in words versus thinking in imagery may be spurious. Since symbols carrying meaning must be isomorphs of real states, the distinction between abstract and concrete cognition can scarcely be upheld. Cognition, even in its conceptual forms, is seen to be always concrete. The dimensions of word storage are thought to be phonological. A preliminary analysis proceeding by using phonetical molecules results in regarding the distinction between inflectional and agglutinating languages as a purely phonological feature, and an explanation is offered as to the different probabilities of word-form change within different languages.     

Social status and language comprehension

Abstract.— Previous research on differences in language use in relation to social status have dealt almost exclusively with language production. The present study investigated the comprehension of connected discourse by 116 adult Danes from two different socio-economic status groups, high status (HSES) and low status (LSES). On a task at the lexical level of comprehension (choosing between alternatives to two words in each of four texts) there appeared no differences between HSES and LSES subjects. At the structural level a difference ( p <0.05) was found in drawing conclusions from the texts, but the groups nevertheless agreed completely ( p <0.05) in underlining important segments of the texts. Thus the symmetry between production and comprehension hypothesized by Bernstein did not appear. The results are interpreted in accordance with a general model of language processing. It is suggested that in the future more attention should be paid to variables other than the purely sociological variable of social status or social class.     

Sensitivity to syntax in visual cortex

One of the most intriguing findings on language comprehension is that violations of syntactic predictions can affect event-related potentials as early as 120 ms, in the same time-window as early sensory processing. This effect, the so-called early left-anterior negativity (ELAN), has been argued to reflect word category access and initial syntactic structure building (Friederici, 2002). In two experiments, we used magnetoencephalography to investigate whether (a) rapid word category identification relies on overt category-marking closed-class morphemes and (b) whether violations of word category predictions affect modality-specific sensory responses. Participants read sentences containing violations of word category predictions. Unexpected items varied in whether or not their word category was marked by an overt function morpheme. In Experiment 1, the amplitude of the visual evoked M100 component was increased for unexpected items, but only when word category was overtly marked by a function morpheme. Dipole modeling localized the generator of this effect to the occipital cortex. Experiment 2 replicated the main results of Experiment 1 and eliminated two non-morphology-related explanations of the M100 contrast we observed between targets containing overt category-marking and targets that lacked such morphology. Our results show that during reading, syntactically relevant cues in the input can affect activity in occipital regions at around 125 ms, a finding that may shed new light on the remarkable rapidity of language processing.     

Constraining the comprehension of pronominal expressions in Chinese

This paper reports a series of self-paced reading time experiments designed to probe how the reference of pronominal expressions is resolved on-line in (Mandarin) Chinese. It is assumed that pronoun resolution is achieved by narrowing the candidate set of potential antecedents for a pronoun. The experimental evidence reported here indicates that two factors--syntactic prominence and the matching of lexical features (e.g. gender)--play a significant role in filtering this candidate set. It is shown that syntactic prominence and feature matching work in conjunction with each other rather than in a competitive, winner-take-all manner. Furthermore, the evidence suggests that syntactic prominence is sensitive to structural relations rather than exclusively to grammatical functions (such as subject and direct object) or semantic roles (such as agent and patient) as has been assumed in the psycholinguistic literature.     

Lexical norms,language comprehension,and the epistemology of testimony

It has recently been argued (for instance by Sanford Goldberg, expanding on earlier work by Tyler Burge) that public linguistic norms are implicated in the epistemology of testimony by way of underwriting the reliability of language comprehension. This paper argues that linguistic normativity, as such, makes no explanatory contribution to the epistemology of testimony, but instead emerges naturally out of a collective effort to maintain language as a reliable medium for the dissemination of knowledge. Consequently, the epistemologies of testimony and language comprehension are deeply intertwined from the start, and there is no room for grounding the one in terms of the other.     

语言理解中的预设加工

预设是指以交际双方的共同背景(共享的知识或信念)为前提的、听话者根据特定语言标记(触发标记)及其限定的对象(计算内容)而推理出的非外显意义。例如,“张明又触发标记发表了论文计算内容”引发了“张明之前发表过论文”的预设推论。理解者依赖触发标记通达交际双方的共同背景,并在计算内容上生成完整的预设;随后,理解者连接生成的预设和共同背景,更新两者之间的关系。触发标记范畴、共同背景与预设的关联度、共同背景类型,以及理解者的参与动机会影响不同阶段的预设加工。未来研究可以从三个角度进一步探讨预设加工的认知基础：(1)采用计算建模的方法,量化交际互动中听话者理解预设的过程(如观点采择);(2)采用脑成像技术,揭示预设加工过程的神经基础;(3)以特殊人群为研究对象,检验和修正预设加工的认知模型。     

The effect of noun phrase type on working memory saturation during sentence comprehension

Double centre-embedded structures such as “the rat the cat the boy chased ate was brown” seem ungrammatical to many human subjects. Using an offline complexity judgement task, Gibson and Thomas (1999) demonstrated that people found such sentences no more difficult to understand when the second verb phrase (VP) was omitted, relative to a condition where all the required VPs were present. According to the Syntactic Prediction Locality Theory (SPLT; Gibson, 1998), this syntactic illusion is determined by the high working memory cost associated with the integration of the second VP. This cost could be reduced by replacing the third noun phrase (the boy) by a pronoun, making the reader more sensitive to the omission of the second VP. This hypothesis was tested in two experiments using French sentences. Both experiments confirmed the syntactic illusion when the second VP was not a pronoun. The second experiment measured the reading times of the VPs and showed that the pronoun induced a longer reading time of the final VP when the second VP was omitted. The overall results indicate a condition under which human subjects could process the most complex part of a sentence with more than one embedded relative clause. The overall results are consistent with most of the hypotheses derived from the SPLT although offline complexity judgements could not be the most sensitive measure to test some of these hypotheses.     

Time in language: event duration in language comprehension

This work investigates how we process and represent event duration in on-line language comprehension. Specifically, it examines how events of different duration are processed and what type of knowledge underlies their representations. Studies 1–4 examined verbs and phrases in different contexts. They showed that durative events took longer to process than non-durative events and that the duration attributed to the stimulus events correlated with on-line processing times. Studies 5 and 6 indicated that durative events occur in semantically more diverse contexts and elicit semantically more diverse associations than non-durative events. Semantic and contextual diversity also correlated with attributed durations and processing times. Results indicate that (a) event-specific durations are computed on-line from multiple unfolding cues, (b) processing cost and duration representations emerge from semantic and contextual diversity reflecting our experience, and (c) key components of duration representations may be situation-specific knowledge of causal and contingency relations between events.     

The relationship between age, verbal working memory, and language comprehension

A structural modeling approach was used to examine the relationships between age, verbal working memory (vWM), and 3 types of language measures: online syntactic processing, sentence comprehension, and text comprehension. The best-fit model for the online-processing measure revealed a direct effect of age on online sentence processing, but no effect mediated through vWM. The best-fit models for sentence and text comprehension included an effect of age mediated through vWM and no direct effect of age. These results indicate that the relationship among age, vWM, and comprehension differs depending on the measure of language processing and support the view that individual differences in vWM do not affect individuals' online syntactic processing.     

Perceptual simulation in developing language comprehension

We tested an embodied account of language proposing that comprehenders create perceptual simulations of the events they hear and read about. In Experiment 1, children (ages 7–13 years) performed a picture verification task. Each picture was preceded by a prerecorded spoken sentence describing an entity whose shape or orientation matched or mismatched the depicted object. Responses were faster for matching pictures, suggesting that participants had formed perceptual-like situation models of the sentences. The advantage for matching pictures did not increase with age. Experiment 2 extended these findings to the domain of written language. Participants (ages 7–10 years) of high and low word reading ability verified pictures after reading sentences aloud. The results suggest that even when reading is effortful, children construct a perceptual simulation of the described events. We propose that perceptual simulation plays a more central role in developing language comprehension than was previously thought.     

Representing object colour in language comprehension

Embodied theories of cognition hold that mentally representing something red engages the neural subsystems that respond to environmental perception of that colour. This paper examines whether implicit perceptual information on object colour is represented during sentence comprehension even though doing so does not necessarily facilitate task performance. After reading a sentence that implied a particular colour for a given object, participants were presented with a picture of the object that either matched or mismatched the implied colour. When asked if the pictured object was mentioned in the preceding sentence, people's responses were faster when the colours mismatched than when they matched, suggesting that object colour is represented differently to other object properties such as shape and orientation. A distinction between stable and unstable embodied representations is proposed to allow embodied theories to account for these findings.     

Syntactic reconstruction and reanalysis,semantic dead ends,and prefrontal cortex

The left inferior frontal gyrus (LIFG) is crucially has been found to be involved in syntactic processing of various kinds. This study investigates the cortical effects of two types of syntactic processes: (i) Reconstruction in ellipsis (recovery of left-out material given by context, More people have been to Paris than […] to Oslo), using pseudo-elliptical structures (‘dead ends’) as control (More people have been to Paris than I have). (ii) Reanalysis in the face of structural ambiguity in syntactic ‘garden paths’, where the parser initially assigns an incorrect structure and is forced to reanalyze. Reanalysis and reconstruction require additional syntactic processing and were predicted to increase activation in areas otherwise involved in structural computation: LIFG (BA 44, 45), premotor BA 6, and posterior temporal BA 21, 22. This was borne out. The results showed an interaction effect of the types of construction in all three areas reflecting syntactic processing.     

Seeing, acting, understanding: motor resonance in language comprehension

Observing actions and understanding sentences about actions activates corresponding motor processes in the observer-comprehender. In 5 experiments, the authors addressed 2 novel questions regarding language-based motor resonance. The 1st question asks whether visual motion that is associated with an action produces motor resonance in sentence comprehension. The 2nd question asks whether motor resonance is modulated during sentence comprehension. The authors' experiments provide an affirmative response to both questions. A rotating visual stimulus affects both actual manual rotation and the comprehension of manual rotation sentences. Motor resonance is modulated by the linguistic input and is a rather immediate and localized phenomenon. The results are discussed in the context of theories of action observation and mental simulation.     

False belief and language comprehension in Cantonese-speaking children

The current research compared two accounts of the relation between language and false belief in children, namely that (a) language is generally related to false belief because both require secondary representation in a social-interactional context and that (b) specific language structures that explicitly code metarepresentation contribute uniquely to the language-false belief relation. In three studies, attempts were made to correlate Cantonese-speaking children's false belief with their general language comprehension and understanding of certain structures that explicitly express metarepresentational knowledge. Results showed that these structures failed to predict false belief after age, nonverbal intelligence, and general language comprehension were considered. In contrast, general language remained predictive of false belief after controlling for age, nonverbal intelligence, and language structures. The current findings are more consistent with a general language account than a language structure account.