语篇语境对句子理解的影响：来自N400的证据

N400作为语义违反的特异性ERP组分,其波幅反映了语义整合加工过程的难度,因此可将其作为研究语篇语境意义建构过程的一项重要指标。语篇语境可分为语言语境和非语言语境。前人一系列基于语篇水平的N400研究表明,从语义的角度上看,语言语境对句子理解具有制约和协调作用,其机制涉及词汇语义启动、场景适宜性、文字内容信息以及因果推理等方面;非语言语境对句子理解具有制约和补充作用,但其机制尚不明确。两种不同来源的语义信息在实时理解中是同时得到加工的     

FN400和N400是相同的ERP成分：来自图形材料的证据

本研究通过比较记忆编码阶段语义启动引起的N400效应和提取阶段熟悉性引起的FN400效应的地形图考察图形材料诱发的N400和FN400是否是相同的ERP成分。实验结果发现,语义启动引起的N400效应和熟悉性引起的FN400效应的地形图没有显著差异。这说明图形材料诱发的FN400和N400是相同的ERP成分,两者都反映了语义加工。本研究为FN400效应反映了语义启动而不是熟悉性的观点提供了新的实验证据。     

The Social N400 effect: how the presence of other listeners affects language comprehension

During conversation, it is necessary to keep track of what others can and cannot understand. Previous research has focused largely on understanding the time course along which knowledge about interlocutors influences language comprehension/production rather than the cognitive process by which interlocutors take each other’s perspective. In addition, most work has looked at the effects of knowledge about a speaker on a listener’s comprehension, and not on the possible effects of other listeners on a participant’s comprehension process. In the current study, we introduce a novel joint comprehension paradigm that addresses the cognitive processes underlying perspective taking during language comprehension. Specifically, we show that participants who understand a language stimulus, but are simultaneously aware that someone sitting next to them does not understand the same stimulus, show an electrophysiological marker of semantic integration difficulty (i.e., an N400-effect). Crucially, in a second group of participants, we demonstrate that presenting exactly the same sentences to the participant alone (i.e. without a co-listener) results in no N400-effect. Our results suggest that (1) information about co-listeners as well as the speaker affect language comprehension, and (2) the cognitive process by which we understand what others comprehend mirrors our own language comprehension processes.     

The N400 effect in children: relationships with comprehension, vocabulary and decoding

Using event-related potentials (ERPs), we investigated the N400 (an ERP component that occurs in response to meaningful stimuli) in children aged 8-10 years old and examined relationships between the N400 and individual differences in listening comprehension, word recognition and non-word decoding. Moreover, we tested the claim that the N400 effect provides a valuable indicator of behavioural vocabulary knowledge. Eighteen children were presented with picture-word pairs that were either ‘congruent’ (the picture depicted the spoken word) or ‘incongruent’ (they were unrelated). Three peaks were observed in the ERP waveform triggered to the onset of the picture-word stimuli: an N100 in fronto-central channels, an N200 in central-parietal channels and an N400 in frontal, central and parietal channels. In contrast to the N100 peak, the N200 and N400 peaks were sensitive to semantic incongruency with greater peak amplitudes for incongruent than congruent conditions. The incongruency effects for each peak correlated positively with listening comprehension but when the peak amplitudes were averaged across congruent/incongruent conditions they correlated positively with non-word decoding. These findings provide neurophysiological support for the position that sensitivity to semantic context (reflected in the N400 effect) is crucial for comprehension whereas phonological decoding skill relates to more general processing differences reflected in the ERP waveform. There were no correlations between ERP and behavioural measures of expressive or receptive vocabulary knowledge for the same items, suggesting that the N400 effect may not be a reliable estimate of vocabulary knowledge in children aged 8-10 years.     

汉字模糊度、字频和语义启动在N400上的交互作用：N400的IA模型的证据

通过两个实验, 采用事件相关电位技术, 记录大学生被试在同一字判断任务中的脑电波形。两个实验涉及三个因素, 包括模糊度、字频和语义, 语义和字频为被试内设计, 以启动字-靶字(模糊)-探测字的呈现序列为一个测试(trial), 要求被试判断靶字和探测字是否是同一个字。两个实验除了靶字的模糊度不同外, 其他材料完全相同。结果发现, 实验1字频和语义启动间存在交互作用, 其中低频条件下无语义启动比语义启动的N400波幅更偏负, 高频条件则无这种差异; 实验2中只存在语义启动效应, 字频与语义启动间不存在交互作用; 综合两个实验的ERP结果, 模糊度、字频和语义启动三者间存在交互作用, 且高频而非低频条件下模糊度与语义间也有交互作用, 无启动条件下字频和模糊度间也存在交互作用。本研究因此支持N400的IA模型(交互激活模型), 不支持核证模型和词汇后加工理论。     

Focus identification during sentence comprehension: Evidence from eye movements

Three eye movement experiments investigated focus identification during sentence comprehension. Participants read dative or double-object sentences (i.e., either the direct or indirect object occurred first), and a replacive continuation supplied a contrast that was congruous with either the direct or the indirect object. Experiments 1 and 2 manipulated focus by locating only adjacent to either the direct or indirect object of dative (Experiment 1) or double-object (Experiment 2) sentences. Reading-time effects indicated that the surface position of the focus particle influenced processing. In addition, Experiment 1 reading times were longer when the replacive was incongruous with the constituent that only adjoined, and particle position modulated a similar effect in Experiment 2. Experiment 3 showed that this effect was absent when only was omitted. We conclude that the surface position of a focus particle modulates focus identification during on-line sentence comprehension.     

An investigation into the online processing of counterfactual and indicative conditionals

The ability to represent conditional information is central to human cognition. In two self-paced reading experiments we investigated how readers process counterfactual conditionals (e.g., If Darren had been athletic, he could probably have played on the rugby team) and indicative conditionals (e.g., If Darren is athletic, he probably plays on the rugby team). In Experiment 1 we focused on how readers process counterfactual conditional sentences. We found that processing of the antecedent of counterfactual conditionals was rapidly constrained by prior context (i.e., knowing whether Darren was or was not athletic). A reading-time penalty was observed for the critical region of text comprising the last word of the antecedent and the first word of the consequent when the information in the antecedent did not fit with prior context. In Experiment 2 we contrasted counterfactual conditionals with indicative conditionals. For counterfactual conditionals we found the same effect on the critical region as we found in Experiment 1. In contrast, however, we found no evidence that processing of the antecedent of indicative conditionals was constrained by prior context. For indicative conditionals (but not for counterfactual conditionals), the results we report are consistent with the suppositional account of conditionals. We propose that current theories of conditionals need to be able to account for online processing differences between indicative and counterfactual conditionals.     

Constituent order and semantic parallelism in online comprehension: Eye-tracking evidence from German

Reading times for the second conjunct of and-coordinated clauses are faster when the second conjunct parallels the first conjunct in its syntactic or semantic (animacy) structure than when its structure differs (Frazier, Munn, & Clifton, 2000; Frazier, Taft, Roeper, & Clifton, 1984). What remains unclear, however, is the time course of parallelism effects, their scope, and the kinds of linguistic information to which they are sensitive. Findings from the first two eye-tracking experiments revealed incremental constituent order parallelism across the board—both during structural disambiguation (Experiment 1) and in sentences with unambiguously case-marked constituent order (Experiment 2), as well as for both marked and unmarked constituent orders (Experiments 1 and 2). Findings from Experiment 3 revealed effects of both constituent order and subtle semantic (noun phrase similarity) parallelism. Together our findings provide evidence for an across-the-board account of parallelism for processing and-coordinated clauses, in which both constituent order and semantic aspects of representations contribute towards incremental parallelism effects. We discuss our findings in the context of existing findings on parallelism and priming, as well as mechanisms of sentence processing.     

Syntactic priming in Chinese sentence comprehension: Evidence from Event-Related Potentials

Using the event-related potential (ERP) technique, this study examined the nature of syntactic priming effects in Chinese. Participants were required to read prime-target sentence pairs each embedding an ambiguous relative clause (RC) containing either the same verb or a synonymous verb. In Chinese, the word de serves as a relative clause marker. During reading a potential Chinese RC structure (either the prime or the target sentence), Chinese readers initially expect to read an Subject–Verb–Object (SVO) structure but the encounter of a relative clause marker de would make readers abandon the initial strategy and reanalyze the structure as a relative clause. A reduced P600 effect was elicited by the critical word de in the target sentence containing the same initial verb as in the prime sentence. No significant reduction of the P600 was observed in the target sentences in the synonymous condition. The results demonstrated that verb repetition but not similarity in meaning produced a syntactic priming effect in Chinese. The constraint-based lexicalist hypothesis and the argument structure theory were adopted to explain the syntactic priming effect obtained in the current study.     

The allocation of memory resources during sentence comprehension: Evidence from the elderly

Two experiments were carried out to examine the ability of elderly subjects to establish syntactically governed dependency relations during the course of sentence comprehension. The findings reveal the manner in which memory constraints operate during syntactic processing.     

N400 and P600 or the role of the ERP correlates in sentence comprehension: some applications to the Italian language

In the present study, event-related brain potentials (ERPs) were applied to the study of language comprehension in the Italian language. The ERPs were recorded from 10 electrodes while the participants read (Experiment 1) or listened (Experiment 2) to sentences containing semantic or syntactic anomalies. Final words that were inconsistent with the sentence context elicited a negative wave at about 400 ms poststimulus that was more concentrated in the posterior sites of the scalp, whereas final words that were incongruous with the grammatical structure (subject-verb nonagreement) elicited a positive wave at about 600 ms poststimulus that was homogeneously distributed on the scalp. The authors found no differences based on the perceptual modality of the stimulus (visual or auditory), nor did they find different ERP correlates as a function of task relevance (explicit-implicit task induction). The available evidence indicated that the ERP response to semantic anomalies was at least partially distinct from the ERP response to syntactic anomalies, and that a syntactic parser is a plausible process included in sentence comprehension. The two semantic and syntactic effects appear as automatic processes of the decoding of the anomalies and also modality-independent processes. Cross-linguistic applications are considered in the general discussion.     

Incidental picture exposure affects later reading: evidence from the N400

Language comprehenders form a mental representation of the implied shape of objects mentioned in the text. In the present study, the influence of prior visual experience on subsequent reading was assessed. In two separate phases, participants saw a picture of an object and read a text about the object, suggesting the same or a different shape. When the shapes in the two phases mismatched, ERPs during reading showed a larger N400 amplitude than when the shapes matched, suggesting that a picture presented incidentally 15 min earlier affected reading. These results further strengthen the case for the interaction of language and visual experience during language comprehension.     

Similarity-based interference during language comprehension: Evidence from eye tracking during reading

The nature of working memory operation during complex sentence comprehension was studied by means of eye-tracking methodology. Readers had difficulty when the syntax of a sentence required them to hold 2 similar noun phrases (NPs) in working memory before syntactically and semantically integrating either of the NPs with a verb. In sentence structures that placed these NPs at the same linear distances from one another but allowed integration with a verb for 1 of the NPs, the comprehension difficulty was not seen. These results are interpreted as indicating that similarity-based interference occurs online during the comprehension of complex sentences and that the degree of memory accessibility conventionally associated with different types of NPs does not have a strong effect on sentence processing.     

Differentiation of stages in joke comprehension: Evidence from an ERP study

This study aimed to investigate the mechanisms underlying joke comprehension using event‐related potentials (ERPs). Fourteen healthy college students were presented with the context of a story without its joke or nonjoke ending, and then, when the story ending was presented, they were asked to make a funny/unfunny judgment about these endings. The behavioral results showed that there was no significant difference between funny and unfunny items, which meant that subjects could understand funny items as easily as unfunny ones. However, the ERP results showed that funny items initially elicited a more negative ERP deflection (N350–450) over frontocentral scalp regions. Dipole analysis localized the generators in the left temporal gyrus and the left medial frontal gyrus; it is suggested that these areas might be involved in detecting the incongruent element in joke comprehension. Between 600 and 800 ms, funny items subsequently elicited a more negative ERP deflection (N600–800) over frontocentral scalp regions and a more positive ERP deflection (P600–800) over posterior scalp regions. Dipole analysis localized the generator in the anterior cingulate cortex (ACC), an area involved in the breaking of mental set/expectation and the forming of novel associations. Finally, funny items elicited a more positive ERP deflection (P1250–1400) over anterior and posterior scalp regions. Dipole analysis localized the generators in the middle frontal gyrus and the fusiform gyrus, areas that might be related to the affective appreciation stage in joke process. Unlike that of Coulson and Kutas (2001), the present study might support the hypothesis of a three stage model of humor processing (humor detection, resolution of incongruity and humor appreciation).     

Effects of language comprehension on visual processing - MEG dissociates early perceptual and late N400 effects

We investigated whether and when information conveyed by spoken language impacts on the processing of visually presented objects. In contrast to traditional views, grounded-cognition posits direct links between language comprehension and perceptual processing. We used a magnetoencephalographic cross-modal priming paradigm to disentangle these views. In a sentence-picture verification task, pictures (e.g. of a flying duck) were paired with three sentence conditions: A feature-matching sentence about a duck in the air, a feature-mismatching sentence about a duck in a lake, and an unrelated sentence. Brain responses to pictures showed enhanced activity in the N400 time-window for the unrelated compared to both related conditions in the left temporal lobe. The M1 time-window revealed more activation for the feature-matching than for the other two conditions in the occipital cortex. These dissociable effects on early visual processing and semantic integration support models in which language comprehension engages two complementary systems, a perceptual and an abstract one.     

Dissociation of algorithmic and heuristic processes in language comprehension: Evidence from aphasia

Three groups of aphasic patients, Broca's, Conduction, and Wernicke's, and a nonaphasic patients control group were tested for comprehension of object-relative center-embedded sentences. The sentences were of three types: sentences in which semantic constraints between words allowed the subjects to assign a correct semantic reading of the sentence without decoding the syntax, sentences in which semantic constraints were relaxed and for which a correct reading was only possible with knowledge of syntactic relationships among words, and sentences which described highly improbable events. The subjects' task was to choose which of two pictures captured the meaning expressed in the sentence. Broca's and Conduction aphasics performed near perfectly on sentences where they could use semantic information. Their performance dropped to chance when they had to use syntactic information. These results support a neuropsychological dissociation of heuristic and algorithmic processes based primarily, though not exclusively, on semantic and syntactic information, respectively.     

Single-word predictions of upcoming language during comprehension: Evidence from the cumulative semantic interference task

Comprehenders predict upcoming speech and text on the basis of linguistic input. How many predictions do comprehenders make for an upcoming word? If a listener strongly expects to hear the word “sock”, is the word “shirt” partially expected as well, is it actively inhibited, or is it ignored? The present research addressed these questions by measuring the “downstream” effects of prediction on the processing of subsequently presented stimuli using the cumulative semantic interference paradigm. In three experiments, subjects named pictures (sock) that were presented either in isolation or after strongly constraining sentence frames (“After doing his laundry, Mark always seemed to be missing one …”). Naming sock slowed the subsequent naming of the picture shirt – the standard cumulative semantic interference effect. However, although picture naming was much faster after sentence frames, the interference effect was not modulated by the context (bare vs. sentence) in which either picture was presented. According to the only model of cumulative semantic interference that can account for such a pattern of data, this indicates that comprehenders pre-activated and maintained the pre-activation of best sentence completions (sock) but did not maintain the pre-activation of less likely completions (shirt). Thus, comprehenders predicted only the most probable completion for each sentence.     

Novel metaphors appear anomalous at least momentarily: evidence from N400

This study addresses a central question in perception of novel figurative language: whether it is interpreted intelligently and figuratively immediately, or only after a literal interpretation fails. Eighty sentence frames that could plausibly end with a literal, truly anomalous, or figurative word were created. After validation for meaningfulness and figurativeness, the 240 sentences were presented to 11 subjects for event related potential (ERP) recording. ERP's first 200 ms is believed to reflect the structuring of the input; the prominence of a dip at around 400 ms (N400) is said to relate inversely to how expected a word is. Results showed no difference between anomalous and metaphoric ERPs in the early window, metaphoric and literal ERPs converging 300-500 ms after the ending, and significant N400s only for anomalous endings. A follow-up study showed that the metaphoric endings were less frequent (in standardized word norms) than were the anomalous and literal endings and that there were significant differences in cloze probabilities (determined from 24 new subjects) among the three ending types: literal > metaphoric > anomalous. It is possible that the low frequency of the metaphoric element and lower cloze probability of the anomalous one contributed to the processes reflected in the early window, while the incongruity and near-zero cloze probability of the anomalous endings produced an N400 effect in them alone. The structure or parse derived for metaphor during the early window appears to yield a preliminary interpretation suggesting anomaly, while semantic analysis reflected in the later window renders a plausible figurative interpretation.