Word category and verb--argument structure information in the dynamics of parsing

One of the core issues in psycholinguistic research concerns the relationship between word category information and verb-argument structure (e.g. transitivity) information of verbs in the process of sentence parsing. In two experiments (visual versus auditory presentation) using event-related brain potentials (ERPs), we addressed this question by presenting sentences in which the critical word simultaneously realized both a word category and a transitivity violation. ERPs for sentences with both types of violation clustered with the patterns for sentences with a word category violation only, but were different from the patterns elicited by argument structure violations in isolation, since only the latter elicited an N400 ERP component. The finding that an argument structure violation evoked an N400 only if the phrase structure of the respective sentence was correct suggests that a successful integration of the word category information of a verb functionally precedes the application of its argument structure information.     

Lexical integration: Sequential effects of syntactic and semantic information

Both semantic and syntactic context constraints can influence word processing at the level of lexical integration. In event-related brain potentials (ERPs), semantic integration is reflected by a negativity around 400 msec (N400), whereas phrase structure assignment and syntactic integration are assumed to be reflected by an early left anterior negativity and a late positivity (P600), respectively. An ERP study is presented in which participants read different types of sentences whose terminal verb was either congruent with the preceding context or incongruent due to a phrase structure violation, a semantic violation, or both. The main finding was that only the pure semantic violation condition, but not the combined semantic and syntactic violation condition, elicited a large N400. The two conditions containing phrase structure violations were predominantly characterized by a P600. Both semantic violation conditions, moreover, displayed a late negativity around 700 msec that overlapped with the P600 in the double violation condition. The absence of an N400 effect for elements that are syntactically as well as semantically incongruent with prior context suggests an early influence of phrase structure information on processes of lexical-semantic integration. The present data are discussed in comparison to previous ERP findings, and a new view of lexical integration processes is proposed.     

句子理解过程中词类加工的功能性质

句法优先理论假设词类加工功能上优先于语义、动词论元结构和话语信息加工。来自德语和法语的证据显示, 词类违反阻断语义整合和动词论元结构加工, 因而词类优先于语义和动词论元结构。关于词类加工在功能上是否优先于话语信息加工, 尚无来自任何语言的证据。汉语证据尽管显示词类并不优先于语义, 但未充分讨论任务因素的影响。将来研究有必要使用ERP技术和违反范式, 从语义整合、动词论元结构加工和话语水平加工等多个层面, 同时操纵词类的正确性和非句法因素, 考察句法特性上与德语和法语不同的语言, 如汉语和韩语。这方面研究将有助于洞察一个语言的语言学特性如何制约或调整词类加工的功能性质。     

The role of structural prediction in rapid syntactic analysis

A number of recent electrophysiological studies of sentence processing have shown that a subclass of syntactic violations elicits very rapid ERP responses, occurring within around 200 ms of the onset of the violation. Such findings raise the question of how it is possible to diagnose violations so quickly. This paper suggests that very rapid diagnosis of errors is possible specifically in situations where the diagnosis problem is tightly constrained by specific expectations generated before the critical word is presented. In an event-related potentials (ERP) study of visual sentence reading participants encountered violations of a word order constraint (...Max's of...) that has elicited early ERP responses in previous studies. Across conditions the illicit sequence was held constant, while sentence context was used to manipulate the expectation for a noun following the possessor Max's, by manipulating the possibility of ellipsis of the head noun. Results showed that the anterior negativity elicited by the word category violation was attenuated when the availability of ellipsis reduced the expectation for a noun in the position of the offending preposition of, with divergence between conditions starting around 200 ms after the onset of the violation. This suggests a role for structural expectations in accounting for very fast syntactic diagnosis processes.     

Identifying the Null Subject: Evidence from Event-Related Brain Potentials

Event-related brain potentials (ERPs) were recorded during spoken language comprehension to study the on-line effects of gender agreement violations in controlled infinitival complements. Spanish sentences were constructed in which the complement clause contained a predicate adjective marked for syntactic gender. By manipulating the gender of the antecedent (i.e., the controller) of the implicit subject while holding constant the gender of the adjective, pairs of grammatical and ungrammatical sentences were created. The detection of such a gender agreement violation would indicate that the parser had established the coreference relation between the null subject and its antecedent. The results showed a complex biphasic ERP (i.e., an early negativity with prominence at anterior and central sites, followed by a centroparietal positivity) in the violating condition as compared to the non-violating conditions. The brain reacts to NP-adjective gender agreement violations within a few hundred milliseconds of their occurrence. The data imply that the parser has properly coindexed the null subject of an infinitive clause with its antecedent.     

Lexical projection and the interaction of syntax and semantics in parsing

A series of self-paced reading studies utilized an embedded anomaly technique to investigate long-distance dependencies with dative verbs. Previous research i our lab demonstrated that argument structure influences the gap-filling process. Experiment I extended that work by demonstrating that dative verbs pattern with other complex transitive verbs (i.e., a fronted filler that is implausible as the direct object will not be interpreted as the direct object until the absence of a noun phrase after the verb forces the postulation of a direct object gap. This pattern contrasts with that of transitive verbs that subcategorize for a single internal argument position, where fronted fillers are obligatorily interpreted as the direct object). Experiments 2 and 3 investigate the prediction that semantic analyses precede syntactic analyses in dative questions. It is argued that the lexical information about argument structure and thematic roles can guide semantic interpretation.This research was supported in part by NSF grant BNS-8617738 and NIH grant HD-22271.     

Anxiety not only increases,but also alters early error-monitoring functions

Anxiety has profound influences on a wide range of cognitive processes, including action monitoring. Eventrelated brain potential (ERP) studies have shown that anxiety can boost early error detection mechanisms, as reflected by an enhanced error-related negativity (ERN) following errors in high-anxious, as compared with low-anxious, participants. This observation is consistent with the assumption of a gain control mechanism exerted by anxiety onto error-related brain responses within the dorsal anterior cingulate cortex (ACC). However, whether anxiety simply enhances or, rather, alters early error detection mechanisms remains unsolved. In this study, we compared the performance of low-versus high-trait-anxious participants during a go/no-go task while high-density EEG was recorded. The two groups showed comparable behavioral performance, although levels of state anxiety increased following the task for high-anxious participants only. ERP results confirmed that the ERN/Ne to errors was enhanced for high-anxious, relative to low-anxious, participants. However, complementary topographic analyses revealed that the scalp map of the ERN/Ne was not identical between the two groups, suggesting that anxiety did not merely increase early error detection mechanisms, but also led to a qualitative change in the early appraisal of errors. Inverse solution results confirmed a shift within the ACC for the localization of neural generators underlying the ERN/Ne scalp map in high-anxious participants, corroborating the assumption of an early effect of anxiety on early error-monitoring functions. These results shed new light on the dynamic interplay between anxiety and error-monitoring functions in the human brain.     

EEG theta and gamma responses to semantic violations in online sentence processing

We explore the nature of the oscillatory dynamics in the EEG of subjects reading sentences that contain a semantic violation. More specifically, we examine whether increases in theta ( approximately 3-7 Hz) and gamma (around 40 Hz) band power occur in response to sentences that were either semantically correct or contained a semantically incongruent word (semantic violation). ERP results indicated a classical N400 effect. A wavelet-based time-frequency analysis revealed a theta band power increase during an interval of 300-800 ms after critical word onset, at temporal electrodes bilaterally for both sentence conditions, and over midfrontal areas for the semantic violations only. In the gamma frequency band, a predominantly frontal power increase was observed during the processing of correct sentences. This effect was absent following semantic violations. These results provide a characterization of the oscillatory brain dynamics, and notably of both theta and gamma oscillations, that occur during language comprehension.     

性别刻板印象表征的形式及神经基础

本实验采用ERP技术,考察性别刻板印象的表征。结果发现,无论启动是上位范畴、子范畴、典型样例还是反例,被试对于刻板印象不一致的表征比一致的表征均诱发了波幅更大的N400,反应时更长。并且,被试对于性别刻板印象的表征存在层级差异。研究结果表明：（1）性别刻板印象的表征存在层级结构。（2）语义启动下,性别刻板印象违背诱发N400效应。（3）性别刻板印象表征存在自上而下的由大脑额叶进行的语义分类加工。     

Gender Electrified: ERP Evidence on the Syntactic Nature of Gender Processing

The central issue of this study concerns the claim that the processing of gender agreement in online sentence comprehension is a syntactic rather than a conceptual/semantic process. This claim was tested for the grammatical gender agreement in Dutch between the definite article and the noun. Subjects read sentences in which the definite article and the noun had the same gender and sentences in which the gender agreement was violated. While subjects read these sentences, their electrophysiological activity was recorded via electrodes placed on the scalp. Earlier research has shown that semantic and syntactic processing events manifest themselves in different event-related brain potential (ERP) effects. Semantic integration modulates the amplitude of the so-called N400. The P600/SPS is an ERP effect that is more sensitive to syntactic processes. The violation of grammatical gender agreement was found to result in a P600/SPS. For violations in sentence-final position, an additional increase of the N400 amplitude was observed. This N400 effect is interpreted as resulting from the consequence of a syntactic violation for the sentence-final wrap-up. The overall pattern of results supports the claim that the on-line processing of gender agreement information is not a content driven but a syntactic-form driven process.     

Differences in the perception and time course of syntactic and semantic violations

A reading time and an ERP experiment conducted in Italian investigated the parser's responses to a syntactic violation (subject-verb number agreement) and to a semantic violation (subject-verb selectional restriction), examining the time course of comprehension processes until sentence end. The reading-time data showed that the syntactic violation was detected earlier than the semantic one and that the two violations differed in the time-course. The ERP data fully supported the reading time data: Syntactic anomalies elicited a left anterior negativity (LAN) and a P600. Semantic anomalies elicited a N400 centred on the parietal sites which started 90 ms later (latency 430 ms) than the LAN. Furthermore, the N400 evoked by the words that followed the target word continued and increased until sentence end. The results are discussed with respect to the hypotheses that the parser constructs distinct syntactic and semantic analyses of a sentence and that this characteristic holds cross-linguistically. The appropriateness of different methodologies to the study of sentence processing is also evaluated.     

Inadequate and infrequent are not alike: ERPs to deviant prosodic patterns in spoken sentence comprehension

The current study on German investigates Event-Related brain Potentials (ERPs) for the perception of sentences with intonations which are infrequent (i.e. vocatives) or inadequate in daily conversation. These ERPs are compared to the processing correlates for sentences in which the syntax-to-prosody relations are congruent and used frequently during communication. Results show that perceiving an adequate but infrequent prosodic structure does not result in the same brain responses as encountering an inadequate prosodic pattern. While an early negative-going ERP followed by an N400 were observed for both the infrequent and the inadequate syntax-to-prosody association, only the inadequate intonation also elicits a P600.     

Early stimulus processing in dysthymia and anhedonia.

Previous event-related brain potential (ERP) research has found that dysthymic subjects differ from control subjects during later stages of information processing. An important issue that emerges from this literature is whether differences found in these ERP components, typically associated with cognitive processing, can be attributed to earlier differences in basic perceptual processing. This study was undertaken to determine whether early processing deficits are apparent in dysthymic persons. Responses of dysthymics (n = 23) were compared with those of anhedonic (n = 15) and normal control (n = 17) subjects. ERPs were recorded while subjects heard tones at 55, 65, 75, 85, and 95 dB. Overall, N1-P1 and N1-P2 components of the ERP increased in a strong linear fashion as stimulus intensity increased. Dysthymics did exhibit a smaller N1-P2 response than normal subjects, which suggests the presence of difficulties in initial perceptual processing.     

Tell me sweet little lies: An event-related potentials study on the processing of social lies

In reading tasks, words that convey a false statement elicit an enhanced N400 brainwave response, relative to words that convey a true statement. N400 amplitude reductions are generally linked to the online expectancy of upcoming words in discourse. White lies, contrary to false statements, may not be unexpected in social scenarios. We used the event-related potential (ERP) technique to determine whether there is an impact of social context on sentence processing. We measured ERP responses to target words that either conveyed a social “white” lie or a socially impolite blunt truth, relative to semantic violations. Word expectancy was controlled for by equating the cloze probabilities of white lying and blunt true targets, as measured in previous paper-and-pencil tests. We obtained a classic semantic violation effect (a larger N400 for semantic incongruities relative to sense making statements). White lies, in contrast to false statements, did not enhance the amplitude of the N400 component. Interestingly, blunt true statements yielded both a late frontal positivity and an N400 response in those scenarios particularly biased to white lying. Thus, white lies do not interfere with online semantic processing, and they do not engage further reanalysis processes, which are typically indexed by subsequent late positivity ERP effects. Instead, an N400 and a late frontal positivity obtained in response to blunt true statements indicate that they were treated as unexpected events. In conclusion, unwritten rules of social communicative behavior influence the electrical brain response to locally coherent but socially inappropriate statements.     

汉语句子理解中句法启动机制的眼动和ERP研究

语言产生的句法启动效应在近20年得到较深入研究。那么, 语言理解和语言产生中, 句法启动效应具有相同的加工机制吗？近些年, 研究者考察了印欧语系语言理解中的启动效应, 但还存在较多争论。这究竟是句法效应, 还是策略或者语义效应, 是词汇驱动还是词汇独立的？而且, 这是人类语言理解的语系特性还是普遍特性？单独采用行为技术、眼动技术或者ERP技术很难为这些争论提供坚实的实验证据和较深入的理论解释。鉴于此, 本项目拟采用眼动和ERP结合的技术, 从心理学、语言学和认知神经科学等多学科交叉的视角考查汉语句子理解的句法启动效应。通过分析眼动和ERP实验提供的一致性和差异性证据, 本项目力图阐明和揭示汉语句子理解中句法启动效应的认知特点和机制, 检验内隐学习理论和论元结构理论在解释句法启动效应时的适用性。     

Prosodic boundaries, comma rules, and brain responses: the closure positive shift in ERPs as a universal marker for prosodic phrasing in listeners and readers

Just as the false comma in this sentence, shows punctuation can influence sentence processing considerably. Pauses and other prosodic cues in spoken language serve the same function of structuring the sentence in smaller phrases. However, surprisingly little effort has been spent on the question as to whether both phenomena rest on the same mechanism and whether they are equally efficient in guiding parsing decisions. In a recent study, we showed that auditory speech boundaries evoke a specific positive shift in the listeners' event-related brain potentials (ERPs) that indicates the sentence segmentation and resulting changes in the understanding of the utterance (Steinhauer et al., 1999a). Here, we present three ERP reading experiments demonstrating that the human brain processes commas in a similar manner and that comma perception depends crucially on the reader's individual punctuation habits. Main results of the study are: (1) Commas can determine initial parsing as efficiently as speech boundaries because they trigger the same prosodic phrasing covertly, although phonological representations seem to be activated to a lesser extent. (2) Independent of the input modality, this phrasing is reflected online by the same ERP component, namely the Closure Positive Shift (CPS). (3) Both behavioral and ERP data suggest that comma processing varies with the readers' idiosyncratic punctuation habits. (4) A combined auditory and visual ERP experiment shows that the CPS is also elicited both by delexicalized prosody and while subjects replicate prosodic boundaries during silent reading. (5) A comma-induced reversed garden path turned out to be much more difficult than the classical garden path. Implications for psycholinguistic models and future ERP research are discussed.     

世界知识在句子理解中的整合时程

Hagoort等(2004)应用背离范式发现世界知识和单词意义在句末的整合是同时进行的。本研究将背离信息提前到句首短语中,旨在探讨世界知识在句子阅读过程中被整合的时程特征。实验采用四词句子为材料,其中第二个词（目标词）含有单词意义或世界知识背离信息,记录并比较被试在阅读后三个词时诱发的脑电变化。结果发现：与正确句子比较,无论是单词意义背离还是世界知识背离,背离目标词均引发出经典的N400,二者在峰值时间和始潜时上无显著差异,但世界知识背离信息诱发的N400波幅值相对较小。句中的后继单词不再诱发类似的N400;但到句子结尾,两类含有背离信息句子的句末正常单词又诱发出类似N400的一个负波。结果提示,在句子理解过程中,世界知识的整合与单词意义的整合相似,可能是随着句子理解过程即时进行的,整合的结果不影响后继信息的加工;但到了句末,读者在对整个句子内容作真实性判断时会对先前进行过的整合再进行考察。     

Structure and process in semantic memory: evidence from event-related brain potentials and reaction times.

Through scalp measurements of the electrical activity of the brain (event-related potentials, or ERPs) recorded while subjects verified the truth of sentences relating exemplars and categories (e.g., ALL DOGS ARE ANIMALS), inferences were made about aspects of semantic processing that were not directly reflected by overt responses. In particular, it is suggested that a negative ERP component that peaks about 400 ms after the onset of the sentence predicate (i.e., N400) is sensitive to structural aspects of semantic memory. The amplitude of this component was modulated by the relatedness of the subject and predicate terms, as well as the hierarchical level of both these terms, but was not sensitive to the truth value of a sentence.     

Selective attention to the color and direction of moving stimuli: Electrophysiological correlates of hierarchical feature selection

Event-related brain potentials (ERPs) were recorded from subjects who attended to pairs of adjacent colored squares that were flashed sequentially to produce a perception of movement. The task was to attend selectively to stimuli in one visual field and to detect slower moving targets that contained the critical value of the attended feature, be it color or movement direction. Attention to location was reflected by a modulation of the early P1 and N1 components of the ERP, whereas selection of the relevant stimulus feature was associated with later selection negativity components. ERP indices of feature selection were elicited only by stimuli at the attended location and had distinctive scalp distributions for features mediated by “ventral” (color) and “dorsal” (motion) cortical areas. ERP indices of target selection were also contingent on the prior selection of location but initially did not depend on the selection of the relevant feature. These ERP data reveal the timing of sequential, parallel, and contingent stages of visual processing and support early-selection theories of attention that stipulate attentional control over the initial processing of stimulus features.     

Relative Clause Gap-Filling in Children with Specific Language Impairment

Children with Specific Language Impairment (SLI) have been observed to have production and perception difficulties with sentences containing long-distance dependencies, but it is unclear whether this is due to impairment in grammatical knowledge or in processing mechanisms. The current study addressed this issue by examining automatic on-line gap-filling in relative clauses, as well as off-line comprehension of the same stimulus sentences. As predicted by both knowledge impairment and processing impairment models, SLI children showed lack of immediate gap-filling after the relative clause verb, in comparison to a control group of typically developing children. However, on the off-line measure of comprehension of the same stimuli sentences, SLI children and TD children did not differ qualitatively. This finding is incompatible with knowledge impairment. We interpret the results to show that SLI children have impaired processing mechanisms (such as temporally delayed gap-filling) but are not impaired in their grammatical knowledge.