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.     

Comprehending Semantic and Grammatical Violations in Italian. N400 and P600 Comparison with Visual and Auditory Stimuli

Arguments about the existence of language-specific neural systems and specifically about the independence of syntactic and semantic processing have focused on the event-related brain measures (ERPs) as tool to monitoring moment-by-moment the cognitive processes underlaid. In the present experiments, the available evidence indicates that the ERP response to semantic anomalies is at least partially distinct from the ERP response to syntactic anomalies and that two distinct processes are activated in sentences comprehension. ERPs were recorded from 10 electrodes while subjects read (Experiment 1) or listened (Experiment 2) to sentences containing semantic or syntactic violations. Final-words that were inconsistent with the sentence context elicited a negative-going wave at about 400 ms poststimulus, whereas penultimate-word incongruous with the grammatical structure (subject–verb non-agreement) elicited a positive-going wave about 600 ms poststimulus. No differences based on the perceptual modality of the stimulus (visual or auditory) nor different ERP correlates as a function of task-relevance (explicit/implicit task induction) were found. The implications of our results for Italian language are explained.     

Brain potentials elicited by prose-embedded linguistic anomalies

Linguistic theories distinguish between syntax (sentence form) and semantics (sentence meaning). Correspondingly, recent studies have shown that syntactic and semantic anomalies elicit distinct changes in the event-related brain potential (ERP). However, these results have been obtained with highly artificial methodologies and have not yet been generalized to more natural reading conditions. Here, we recorded ERPs while subjects read a naturalistic prose passage. The subjects either read for comprehension with no other task being assigned or read for comprehension and made acceptability judgments after each sentence. Consistent with prior work and regardless of the subjects' assigned task, syntactic anomalies elicited a large positive wave (P600), whereas semantic anomalies elicited a large increase in N400 amplitude. These results demonstrate that the qualitatively distinct ERP responses elicited by syntactic and semantic anomalies are not artifacts of unnatural aspects of previously used stimuli, thereby providing additional evidence that separable syntactic and semantic processes exist.     

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.     

A comparison of semantic and syntactic event related potentials generated by children and adults

The present study employs event related potentials (ERPs) to verify the utility of using electrophysiological measures to study developmental questions within the field of language comprehension. Established ERP components (N400 and P600) that reflect semantic and syntactic processing were examined. Fifteen adults and 14 children (ages 8-13) processed spoken stimuli containing either semantic or syntactic anomalies. Adult participants showed a significant N400 in response to semantic anomalies and P600 components in response to syntactic anomalies. Children also show evidence of both ERP components. The children's N400 component differed from the adults' in scalp location, latency, and component amplitude. The children's P600 was remarkably similar to the P600 shown by adults in scalp location, component amplitude, and component latency. Theoretical implication for theories of language comprehension in adults and children will be discussed.     

Structure and limited capacity in verbal working memory: a study with event-related potentials

In order to test recent claims about the structure of verbal working memory, two ERP experiments with Dutch speaking participants were carried out. We compared the ERP effects of syntactic and semantic mid-sentence anomalies in subject and object relative sentences. In Experiment 1, the participants made acceptability judgments, while in Experiment 2 they read for comprehension. Syntactic anomalies concerned subject-verb disagreement, while semantic anomalies were related to implausible events (e.g., *The cat that fled from the mice ran through the room). Semantic anomalies did not elicit an N400 effect. The semantic as well as syntactic anomalies elicited P600 effects, with similar centro-parietal scalp distributions. For both kinds of anomaly, the P600 effects were modulated by syntactic complexity: they were either relatively small (Experiment 1) or absent (Experiment 2) in object relative sentences. Taken together, our results suggest that: (a) verbal working memory is a limited capacity system; (b) it is not subdivided into an interpretative and a post-interpretative component (); (c) the P600 can reflect the presence of a semantic bias in syntactically unambiguous sentences; (d) the P600 is related to language monitoring: its function is to check upon the veridicality of an unexpected (linguistic) event; (e) if such a check is made, there is no integration of the event and hence no N400 effect.     

绝句韵律边界的认知加工及其脑电效应

语言理解过程中, 句子内部的韵律短语边界会诱发反映韵律短语终止的特异性脑电成分终止正漂移 (CPS, closure positive shift), 而句末语调短语边界则会诱发反映句法终止和完整语言单元结束的脑电效应P3。研究采用汉语特有的语篇绝句, 考察了听者加工绝句中各句末语调短语边界的认知过程及其诱发的脑电效应。结果发现五言绝句内部各语调短语边界分别诱发了时间进程、头皮分布和波幅均相同的CPS, 表明语篇内部韵律边界加工不受其所处语篇位置的影响; 五言和七言绝句末的韵律边界则分别诱发了一个P3, 并且前者诱发的P3波幅小于后者, 而二者在时间进程和头皮分布上不存在差异。本研究表明, 句末语调短语边界诱发何种脑电效应与其承担的功能有关, 既表示前面信息终止又预期后面信息出现的句末边界会诱发CPS, 而只表示信息终止的句末边界则会诱发P3。     

On the Brain Response to Syntactic Anomalies: Manipulations of Word Position and Word Class Reveal Individual Differences

In two experiments, event-related brain potentials (ERPs) were recorded from 13 scalp locations while subjects read sentences containing a syntactically or a semantically anomalous word. The position (sentence-embedded vs sentence-final) and word class (open vs closed) of the syntactic anomalies were manipulated. In both experiments, semantically anomalous words elicited an enhanced N400 component. Syntactically anomalous closed class words elicited a widely distributed late positive wave (P600) regardless of the word's position and a smaller negative-going effect that was largest over anterior sites when the anomaly occurred in sentence-final position. The response to syntactically anomalous open class words revealed striking qualitative individual differences: These words elicited a P600 response in the majority of subjects and an N400 response in others. The proportion of subjects exhibiting the N400 response was greater when the anomaly occurred in sentence-final position. These results are interpreted in the context of prior findings, and implications for the hypothesis that syntactic and semantic anomalies elicit distinct brain potentials are discussed.     

Influences of semantic and syntactic context on open- and closed-class words

Event-related potentials (ERPs) were recorded as subjects read semantically meaningful, syntactically legal but nonsensical and random word strings. The constraints imposed by formal sentence structure alone did not reduce the amplitude of the N400 component elicited by open-class words, whereas semantic constraints did. Semantic constraints also eliminated the word-frequency effect of a larger N400 for low-frequency words. Responses to closed-class words exhibited reduced N400 amplitudes in syntactic and congruent sentences, indicating that formal sentence structure placed greater restrictions on closed-class words than it did on open-class words. However, unlike the open-class results, the impact of sentence context on closed-class words was stable across word positions, suggesting that these syntactic constraints were applied only locally. A second ERP component, distinct from the N400, was elicited primarily by congruent closed-class words.     

Event-related brain potentials and human language

The human capacity to produce and comprehend language is one of the most distinctive characteristics of our species. However, understanding the cognitive and neural underpinnings of human language has proved difficult, in part because these processes are rapid, complex and (for the most part) inaccessible to conscious reflection. Methodologies are needed that provide continuous measurement during language processing and that do not rely on a conscious response. One such method involves the recording of event-related brain potentials (ERPs) elicited during language comprehension or production. ERPs are continuous, multidimensional records of the electrical activity that occurs in the brain during the process of interest. We review recent work demonstrating that ERPs are quite sensitive to (at least some of) the psychological and neural events underlying human language. Indeed, researchers have used ERPs to investigate the separability of syntactic and semantic processes, the on-line analysis of sentence constituent structure and the lexical processing capacities of language-disordered populations.     

网络语言的创造性加工过程:新颖N400与LPC

采用事件相关电位(ERP)技术比较在语义违反范式下网络语言和标准汉语的语义加工差异。结果发现:(1)不管是网络语言还是标准汉语,相对于语义一致条件,语义不一致条件在400 ms诱发了一个更负的负成分,但网络语言的经典N400差异波具有更晚的潜伏期和更长的持续时间;(2)溯源结果发现,网络语言和标准汉语的经典N400差异波的早期和晚期的定位均分别定位于丘脑和前扣带回,表明N400延迟效应是由个体对网络语言相对低的流利度所致,反映了认知冲突的延续;(3)在语义一致性条件下,网络语言比标准汉语诱发了一个更负的新颖N400和一个更正的晚期正成分(LPC),分别定位于前扣带回和海马,二者分别反映了新颖网络含义的识别以及新颖语义信息的整合与新颖语义联结的形成。ERP结果支持了网络语言加工属于创造性思维过程。     

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。     

Code-switching effects in bilingual word recognition: a masked priming study with event-related potentials

Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50 ms in Experiment 1 and 100 ms in Experiment 2). Participants had to monitor target words for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For target words in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 target words, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250 ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching.     

句子理解的关键——对句法和语义关系的再探讨

对于句子理解中句法和语义的关系,传统的模块化观点认为,句法信息优先于语义信息,句法加工支配着句子的理解过程。近期,这种强调句法优先的理论受到了一系列ERP（Event-related potentials）研究结果的挑战,这些研究从不同角度论证了语义信息对句法加工及句子整合加工的重要作用。基于这些研究发现,研究者提出句子理解过程中句法和语义的关系并非一成不变：一些情况下可能是句法支配语义加工,而另一些情况下则可能是语义引导句法加工     

Processing biological gender and number information during Chinese pronoun resolution: ERP evidence for functional differentiation

There have been a number of behavioral and neural studies on the processing of syntactic gender and number agreement information, marked by different morpho-syntactic features during sentence comprehension. By using the event-related potential (ERP) technique, the present study investigated whether the processing of semantic gender information and the processing of notional number information can be differentiated and to what extent they might interact during Chinese pronoun resolution. The pronoun (with singular form in Experiment 1 and with plural form in Experiment 2) in a sentence matched its antecedent or mismatched it with respect to either biological gender or notional number or both. While the number mismatch elicited a P600 effect starting from 550 ms (for singular pronoun) or 400 ms (for plural pronoun) post-onset of the pronoun, the gender mismatch elicited an earlier (for singular) and larger (for both singular and plural) P600 effect. More importantly, the double mismatch produced a P600 effect identical to the effect elicited by the single gender mismatch. These results demonstrate that biological gender information and notional number information are processed differentially and have different processing priorities during Chinese pronoun resolution.     

Time course and task dependence of emotion effects in word processing

The emotional content of stimuli influences cognitive performance. In two experiments, we investigated the time course and mechanisms of emotional influences on visual word processing in various tasks by recording event-related brain potentials (ERPs). The stimuli were verbs of positive, negative, and neutral valence. In Experiment 1, where lexical decisions had to be performed on single verbs, both positive and negative verbs were processed more quickly than neutral verbs and elicited a distinct ERP component, starting around 370 msec. In Experiment 2, the verbs were embedded in a semantic context provided by single nouns. Likewise, structural, lexical, and semantic decisions for positive verbs were accelerated, and an ERP effect with a scalp distribution comparable to that in Experiment 1 now started about 200 msec earlier. These effects may signal an automatic allocation of attentional resources to emotionally arousing words, since they were not modulated by different task demands. In contrast, a later ERP effect of emotion was restricted to lexical and semantic decisions and, thus, appears to indicate more elaborated, task-dependent processing of emotional words.     

汉语隐喻理解时程的ERPs研究

摘 要 本研究使用ERPs技术考察隐喻句与本义句理解时程的异同,以研究汉语隐喻的理解机制。以句尾范式向被试随机呈现本义句、熟悉隐喻句、新奇隐喻句及错误义句各50句,被试的任务为判断每句话是否有意义。结果显示：两种隐喻句诱发的N400波形与头皮分布情况和本义句无明显差异,且两种隐喻句诱发的N400波幅高于本义句。本研究结果证明汉语隐喻义和本义理解的认知机制类似,支持隐喻理解的平行加工假说,且加工隐喻义需要耗费更多的认知资源。     

Rapid extraction of gist from visual text and its influence on word recognition

Two experiments explored rapid extraction of gist from a visual text and its influence on word recognition. In both, a short text (sentence) containing a target word was presented for 200 ms and was followed by a target recognition task. Results showed that participants recognized contextually anomalous word targets less frequently than contextually consistent counterparts (Experiment 1). This context effect was obtained when sentences contained the same semantic content but with disrupted syntactic structure (Experiment 2). Results demonstrate that words in a briefly presented visual sentence are processed in parallel and that rapid extraction of sentence gist relies on a primitive representation of sentence context (termed protocontext) that is semantically activated by the simultaneous presentation of multiple words (i.e., a sentence) before syntactic processing.     

情绪韵律调节情绪词识别的ERP研究

采用韵律/词汇干扰范式和延迟匹配任务, 通过两个ERP实验, 考察了汉语口语中情绪韵律能否、以及如何调节情绪词的识别。实验一中, 不同类型的情绪韵律分组呈现, ERP结果显示, 同与情绪韵律效价一致的情绪词相比, 与情绪韵律效价不一致的情绪词诱发了走向更负的P200、N300和N400成分; 实验二中, 不同类型的情绪韵律随机呈现, 上述效价一致性效应依然存在。实验结果表明, 情绪韵律能够调节情绪词识别, 主要表现在对情绪词的音韵编码和语义加工的双重易化上。     

Iconic gestures prime related concepts: An ERP study

To assess priming by iconic gestures, we recorded EEG (at 29 scalp sites) in two experiments while adults watched short, soundless videos of spontaneously produced, cospeech iconic gestures followed by related or unrelated probe words. In Experiment 1, participants classified the relatedness between gestures and words. In Experiment 2, they attended to stimuli, and performed an incidental recognition memory test on words presented during the EEG recording session. Event-related potentials (ERPs) time-locked to the onset of probe words were measured, along with response latencies and word recognition rates. Although word relatedness did not affect reaction times or recognition rates, contextually related probe words elicited less-negative ERPs than did unrelated ones between 300 and 500 msec after stimulus onset (N400) in both experiments. These findings demonstrate sensitivity to semantic relations between iconic gestures and words in brain activity engendered during word comprehension.