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。     

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.     

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.     

Is the P600/SPS affected by the richness of semantic content? A linguistic ERP study in Swedish

The study investigated whether the P600/SPS component is sensitive to the richness of semantic content in sentences. ERPs were recorded while 30 native Swedish speakers read sentences, of which half were syntactically correct and half contained a syntactic violation. Both kinds of sentences came in one of three types of descending semantic completeness: semantically coherent sentences, sentences which were incoherent due to violations of selectional restrictions, or sentences of pseudo words, hence void of lexical content. In the semantically coherent sentences a P600/SPS was found for the syntactic violation. A less salient positivity was found for the violation in the semantically incoherent sentences. No P600/SPS was found for the syntactic violation in the pseudo word sentences and no LAN component in any sentence type. The results are interpreted as supporting the hypothesis that the P600/SPS component reflects a semantically based reanalysis process.     

Making sense of sentences in schizophrenia: electrophysiological evidence for abnormal interactions between semantic and syntactic processing

Event-related potentials to critical verbs were measured as patients with schizophrenia and healthy controls read sentences word by word. Relative to their preceding context, critical verbs were (a) congruous, (b) incongruous and semantically unrelated to individual preceding words (pragmatic-semantic violations), (c) incongruous but semantically related to individual preceding words (animacy-semantic violations), or (d) syntactically anomalous. The N400 was modulated normally in patients, suggesting that semantic integration between individual words within sentences was normal in schizophrenia. The amplitude of the P600 to both syntactic and animacy-semantic violations was reduced in patients relative to controls. The authors suggest that, in schizophrenia, an abnormality in combining semantic and syntactic information online to build up propositional meaning leaves sentence processing to be primarily driven by semantic relationships between individual words.     

What's different in second-language processing? Evidence from event-related brain potentials

German sentences which were either correct, contained a selectional restriction violation, or a word category violation were presented auditorily to 16 native speakers of German (L1 group) and to 16 native speakers of Russian, who had learned German after the age of 10 (L2 group). Semantic violations elicited an N400 effect for both groups, but with a reduced amplitude and a longer peak latency in the L2 group. Compared to correct sentences, sentences with a phrase structure violation elicited an early anterior negativity followed by a broad centro-parietal positivity in native speakers. By contrast, there was no differential modulation of the early anterior negativity in the L2 group. A late positivity was also elicited in the second language learners, but it was slightly delayed compared to that shown by native speakers. This pattern is discussed in terms of different degrees of automaticity with respect to the subprocesses involved in sentence comprehension.     

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.     

语义信息复杂度对二语者英语被动句加工的影响

采用英语所独有且非常重要的句法结构——被动语态作为语言材料,选取某些可以在句子中的词汇顺序基本没有变化的情况下转换为汉语句式（汉语“被”字句）的“直译型”被动句以及必须根据其意义进行句式转换方能形成相应的汉语句式（汉语主动句）的“意译型”被动句作为实验材料,探讨了在动词语义复杂条件下二语熟练度（包括晚期中等熟练者和高熟练者）对被动句加工过程的影响。结果表明：高熟练者正确率均高于中等熟练者,说明在动词语义复杂的情况下熟练度依然可以预测英语被动句实时加工的程度和水平。此时,语义违例的正确率最高、反应时最短,句法违例句则与之相反。双违例引发的N400效应显著,正确句和句法违例均未引发负向的N400;高熟练者P600的波幅明显高于中等熟练者,句法违例和双违例引发的P600效应最显著。行为指标支持语言间句法加工相似性效应——直译句反应快、正确率高。ERP数据则得出了与之相反的结果：直译句比意译句诱发出更大的N400效应,意译句则引发了较大的P600。上述结果进一步说明二语熟练度对语言间句法加工相似性效应具有很强的调节作用。     

句子阅读理解过程中句意的建构时间

一般语言学理论认为, 在句子阅读理解过程中, 句子意义建构是基于词汇语义整合的, 其反映在N400之上, 开始于词语呈现后约250 ms。然而, 近年关于语义P600效应的研究却提示句意建构可能存在多通道或方式, 读者甚至可能在N400反映的加工出现之前就已建立了初步句意。为探明在句子阅读理解过程中是否存在比N400反映的加工更早的句意建构, 以及如果存在这样的句意建构, 其是从何时开始的, 本研究开展了四个实验。实验1发现被试在句末双字词呈现200 ms后已将其联系到上文语义表征而建立了句意, 提示句意建构开始于N400反映的加工出现之前。实验2与3进一步发现, 读者开始建立句意的时间约在句末词呈现了150 ms之时。实验4排除了实验1~3效应的其他一些可能解释, 提升了实验1~3结果的可靠性。总体上, 本研究提示：在句子阅读理解过程中, 读者在句末双字词呈现了约150 ms之时就已建立了句意; 可能存在比N400反映的加工更早的句意建构。     

汉、英句法结构相似性与第二语言的熟练度对第二语言句法加工的影响

采用事件相关电位（ERP）技术,考察了汉、英句法结构相似性与第二语言（英语）熟练度对第二语言句法加工的影响。实验材料包含与汉语句法结构相似和不同的两种英语句法结构违反的句子。结果发现：与正确句子相比,相似句法违反句在高熟练组被试中,引发正向的ERP波形偏转（150-800ms）,而在低熟练组被试中,只引发了降低的N400（300-550ms）效应;对于不同句法违反句,无论高低熟悉程度的被试,均未出现显著的ERP效应。研究结果表明,第二语言句法与母语的相似性越高,加工起来更容易;第二语言熟练度水平对第二语言句法加工具有一定的促进作用,但受到两种语言句法结构相似性的影响,相似性越高,熟练度的促进作用越大。     

语篇背景在语义整合中的作用

通过眼动实验考察了语篇背景对不同类型句子语义整合过程的影响。句子类型有3个水平：(1)宾语违反了动词的选择性限制; (2)宾语符合选择性限制, 但是违反了世界知识; (3)无违反。语篇背景有2个水平：(1)中性背景; (2)校正背景。在中性语篇背景下, 句子(1) (2)是不合适的; 而在校正背景下, 三种句子都是合理的。24名大学生被试自然阅读的眼动数据表明, 违反动词选择性限制的目标词上的首次注视时间、回视路径时间和总注视时间, 在中性背景下比在校正背景下长, 注视点个数也更多; 而在非选择性限制违反条件下, 语篇背景的效应只在总注视时间和注视点个数两个指标上显著。这些结果表明, 当句子中的宾语违反了动词的选择性限制时, 语篇背景影响了宾语的早期和晚期加工。而当宾语只违反世界知识时, 语篇背景的作用体现在晚期阶段。语篇背景对当前信息的整合是动态的过程, 并不是只能在固定某个阶段起作用。     

Is Semantic Processing During Sentence Reading Autonomous or Controlled? Evidence from the N400 Component in a Dual Task Paradigm

The present study contributes to the discussion on the automaticity of semantic processing. Whereas most previous research investigated semantic processing at word level, the present study addressed semantic processing during sentence reading. A dual task paradigm was combined with the recording of event-related brain potentials. Previous research at word level processing reported different patterns of interference with the N400 by additional tasks: attenuation of amplitude or delay of latency. In the present study, we presented Spanish sentences that were semantically correct or contained a semantic violation in a critical word. At different intervals preceding the critical word a tone was presented that required a high-priority choice response. At short intervals/high temporal overlap between the tasks mean amplitude of the N400 was reduced relative to long intervals/low temporal overlap, but there were no shifts of peak latency. We propose that processing at sentence level exerts a protective effect against the additional task. This is in accord with the attentional sensitization model (Kiefer & Martens, 2010), which suggests that semantic processing is an automatic process that can be enhanced by the currently activated task set. The present experimental sentences also induced a P600, which is taken as an index of integrative processing. Additional task effects are comparable to those in the N400 time window and are briefly discussed.     

语义整合的早期加工:来自ERPs的证据

本研究借助ERPs技术,通过操纵关键词与当前语境的语义合理性关系,考察在严格限定关键词词频变异性的情况下,语义整合过程能否反映在P2效应上。ERPs结果发现关键词呈现后,语义合理相比违背条件在右侧脑区诱发了更大的P2成分。该结果支持如果关键词低水平的变量信息(词频等)得到适当控制,ERPs技术可以检测到发生在250ms以前的语义整合过程。     

Working memory and inferences: evidence from eye fixations during reading

Eye fixations during reading were monitored to examine the relationship between individual differences in working memory capacity-as assessed by the reading span task-and inferences about predictable events. Context sentences predicting likely events, or non-predicting control sentences, were presented. They were followed by continuation sentences in which a target word represented an event to be inferred (inferential word) or an unlikely event (non-predictable word). A main effect of reading span showed that high working memory capacity was related to shorter gaze durations across sentence regions. More specific findings involved an interaction between context, target, and reading span on late processing measures and regions. Thus, for high- but not for low-span readers, the predicting condition, relative to the control condition, facilitated reanalysis of the continuation sentence that represented the inference concept. This effect was revealed by a reduction in regression-path reading time in the last region of the sentence, involving less time reading that region and fewer regressions from it. These results indicate that working memory facilitates elaborative inferences during reading, but that this occurs at late text-integration processes, rather than at early lexical-access processes.     

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.     

Localization of Syntactic Comprehension by Positron Emission Tomography

Positron Emission Tomography (PET) was used to determine regional cerebral blood flow (rCBF) when eight normal right-handed males read and made acceptability judgments about sentences. rCBF was greater in Broca's area (particularly in the pars opercularis) when subjects judged the semantic plausibility of syntactically more complex sentences as compared to syntactically less complex sentences. rCBF was greater in left perisylvian language areas when subjects had to decide whether sentences were semantically plausible than when subjects had to decide whether syntactically identical sentences contained a nonsense word. The results of this experiment suggest that overall sentence processing occurs in regions of the left perisylvian association cortex. The results also provide evidence that one particular aspect of sentence processing (the process that corresponds to the greater difficulty of comprehending center-embedded than right-branching relative clause sentences) is centered in the pars opercularis of Broca's area. This process is likely to be related to the greater memory load associated with processing center-embedded sentences.     

Beginning adult L2 learners' sensitivity to morphosyntactic violations: A self-paced reading study

This study investigated beginning adult second language (L2) learners' sensitivity to L2 morphosyntactic violations as a function of cross-language similarity. Online sensitivity was indexed by self-paced reading times at: (1) the critical word at which the violation could first be detected, (2) the post-critical word, and (3) the sentence-final word. In conditions in which morphosyntactic marking systems were similar or different in L1 and L2, reading times on the critical word were slower when it cued a violation than when it did not; however, this sensitivity was not apparent in a construction unique to L2. Slower reading times to violations spilled over onto the post-critical word. Cross-language similarity also influenced sentence-final word reading times. Despite this online sensitivity, post-sentence grammaticality judgements were generally poor. However, these judgements were influenced by morphosyntactic markings on words after the critical word, suggesting that learners can make use of this information.     

Verb agreements during on-line sentence processing in Alzheimer's disease and frontotemporal dementia

An on-line "word detection" paradigm was used to assess the comprehension of thematic and transitive verb agreements during sentence processing in individuals diagnosed with probable Alzheimer's Disease (AD, n=15) and Frontotemporal Dementia (FTD, n=14). AD, FTD, and control participants (n=17) were asked to listen for a word in a sentence. Unbeknownst to the participants, the target word followed an agreement involving a verb's transitivity or thematic role component. Control participants took significantly longer to respond to a target word only when it immediately followed a violation of a thematic role agreement or a transitivity agreement, relative to target word detection immediately following the corresponding correct agreement. AD patients were selectively insensitive to thematic role agreement violations, although they demonstrated a normal processing pattern for transitivity agreements. This is consistent with previous observations showing selective difficulty with the thematic role component of a verb in AD. FTD patients were insensitive to violations of thematic role and transitivity agreements. FTD patients' impairment for both transitivity and thematic role agreements may reflect a broader degradation of verb knowledge that involves both grammatical and semantic representations, or difficulty processing sentence structure that also causes a thematic role deficit.     

Speeded recognition of ungrammaticality: Double violations

A model of sentence comprehension postulating that Subject-Verb-Object relations are specified prior to Noun-Adjective relations received support from a study of the speed at which sentences with various kinds of violations could be rejected. Compatible with the sequential model was the finding that Noun-Verb and Adjective-Noun double violations did not result in shorter RTs than Noun-Verb single violations — even though sentences with double violations were judged to be less acceptable.     

The retention of nouns,adjectives, and verbs of sentences

This research compared the retention of nouns, adjectives and verbs of sentences. A model of the structure underlying the retention of sentences and in which deep structure constituent propositions are hierarchically related, was used to make predictions concerning the retention of these word classes. The model was not supported by the data and it was determined that latencies to recognize the words of a previously presented sentence were the same for all classes of words. This result indicated that for recognition (but not necessarily for other memory tasks), each word of a sentence is seperately or equally accessible (as long as inter-word imagery is the same). However, a further experiment showed that, although word class is not a variable, the image-arousing capacity of a word is. Latencies and error rates were much lower for high-imagery words than for low-imagery ones. The findings on error rates in recognizing words were interesting and pointed to a different model where the meaning representations and syntatic functions of words have an active role in sentence retention.