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。     

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.     

Non-target language processing in Chinese-English bilinguals: a study of event-related potential

The event-related brain potential (ERP) technique was used to investigate the neural mechanism of non-target language processing in Chinese-English bilinguals. Participants were presented with a mixed list of Chinese and English words and required to make conceptual decisions for words in one language and ignore words in the other non-target language. Regardless of whether the nontarget word was in Chinese or English, the ERPs they elicited were modulated by word frequency, suggesting that their meaning had been accessed. The N400 peak was delayed in the English as the non-target language condition, probably because participants were less proficient in English. The results suggest that the non-target language can be processed during conceptual tasks with participants' proficiency in this language being a critical factor.     

不同性质的汉语高熟悉度隐喻意义加工过程——来自ERP研究的证据

采用ERP技术考察不同性质隐喻加工的时间进程与神经机制。以词对方式呈现词源性隐喻、引发性隐喻、一般字面义,被试进行语义相关判断任务。结果发现:从引发性隐喻、一般字面义到词源性隐喻,N400平均波幅呈阶梯状递减,引发性隐喻和词源性隐喻的P600平均波幅大于一般字面义。对于不同类型词对诱发的N400,大脑左半球没有显著差异,但右半球上引发性隐喻显著大于词源性隐喻和字面义词对。并且右半球P600平均波幅更大,但三种词对间没有显著差异。结果表明:(1)日常熟悉隐喻的理解更符合平行假说但需要更多的认知资源;(2)右半球是否参与以及参与程度与隐喻性质和加工阶段有关。     

科学语言的认知神经加工机制研究:来自ERP的证据

本研究采用尾词范式,使用ERP技术,对比分析了科学语言(隐喻和直义)与日常语言诱发的N400和LPC平均波幅和激活脑区的异同,从而探讨了科学语言认知加工机制的神经特异性。实验结果表明,与日常语言相比,在科学语言认知加工过程中,语义检索和提取难度更大,顶叶区尤其是右顶叶区的激活程度最为显著,左右脑都发挥了重要作用。此外,科学隐喻的相关研究发现支持隐喻加工的意义显性度假说,科学语言特有的复杂性和抽象性降低了语言表达的显性度,并且对后期的语义整合阶段产生影响。     

ERP evidence for conceptual mappings and comparison processes during the comprehension of conventional and novel metaphors

Cognitive linguists suggest that understanding metaphors requires activation of conceptual mappings between the involved concepts. We tested whether mappings are indeed in use during metaphor comprehension, and what mapping means as a cognitive process with Event-Related Potentials. Participants read literal, conventional metaphorical, novel metaphorical, and anomalous target sentences preceded by primes with related or unrelated mappings. Experiment 1 used sentence-primes to activate related mappings, and Experiment 2 used simile-primes to induce comparison thinking. In the unprimed conditions of both experiments, metaphors elicited N400s more negative than the literals. In Experiment 1, related sentence-primes reduced the metaphor-literal N400 difference in conventional, but not in novel metaphors. In Experiment 2, related simile-primes reduced the metaphor-literal N400 difference in novel, but not clearly in conventional metaphors. We suggest that mapping as a process occurs in metaphors, and the ways in which it can be facilitated by comparison differ between conventional and novel metaphors.     

语言类比推理的神经机制：来自ERP研究的证据

实验通过“A:B::C:D”范式, 采用事件相关电位技术, 考察了语言类比推理的神经机制。实验结果显示：图式生成阶段诱发出N400和P300成分, 反映了类比源域的词对概念通达和词对关系抽取的加工过程; 类比映射阶段诱发出N400和晚期负成分LNC, 反映了类比目标域前项词汇概念意义的激活, 以及将已获取的图式关系类比映射于目标域, 并进行推理的加工过程。研究结果表明, 语言类比推理的神经机制复杂, 牵涉到一系列认知加工步骤; LNC成分与类比映射阶段的加工关系密切, 其波幅和头皮分布的广泛性情况与类比映射关系的复杂程度成正比。     

部件表征在合体字识别中的作用——来自ERP的证据

文采用延迟反应的同一字判断任务,记录了大学生被试由部件数不同的两种残缺汉字诱发的事件相关电位(ERP)。结果发现部件少(笔画删除)比部件多(部件删除)的残缺字产生更小的P200,更大的N400,表明简单部件在合体字识别中起到一种中间层单元的作用;P200效应符合关于部件少比部件多的残缺字激活更多的部件家族成员的假设,而更多家族成员的激活使残缺字的整字内部表征受到的侧抑制更多,体现为更大的N400。双效应支持多层交互激活模型及其侧抑制机制。     

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.     

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.     

A comparison of sentence- and discourse-level semantic processing: an ERP study

Eighteen subjects listened to sentences ending with semantically congruent or incongruent words. Each congruent sentence was embedded at the end of a short story so that the final word was semantically acceptable at the sentence level but incongruent in terms of discourse context. The same stories were also presented with congruent endings. Auditory ERPs elicited by the final words in these sentences and stories were compared. Both sentence- and discourse-level semantic integration were associated with N400 and Late Positive Component (LPC) effects in addition to a new component, P550. Local and global semantic processing, although evoking the same components, were characterized by differential effects on ERP amplitudes according to the amount of text integrated and its congruence. These results indicate similar cognitive processes of context build up, underlying sentence- and discourse-semantic processing.     

Two languages, one developing brain: event-related potentials to words in bilingual toddlers

Infant bilingualism offers a unique opportunity to study the relative effects of language experience and maturation on brain development, with each child serving as his or her own control. Event-related potentials (ERPs) to words were examined in 19- to 22-month-old English-Spanish bilingual toddlers. The children's dominant vs. nondominant languages elicited different patterns of neural activity in the lateral asymmetry of an early positive component (P100), and the latencies and distributions of ERP differences to known vs. unknown words from 200-400 and 400-600 ms. ERP effects also differed for 'high' and 'low' vocabulary groups based on total conceptual vocabulary scores. The results indicate that the organization of language-relevant brain activity is linked to experience with language rather than brain maturation.     

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。     

熟悉性对汉语隐喻义与本义加工机制的影响

采用句子违反范式考察汉语隐喻义与本义加工机制的差异及隐喻熟悉性的调节作用。要求被试阅读不同熟悉性的隐喻和本义句子并判断句子正确性,记录其行为与脑电反应。结果显示,熟悉句子隐喻义的加工显著快于本义的加工,而新奇句子则本义的加工更快;脑电水平上,对于熟悉句子,隐喻义违反比本义违反诱发增强的N400和降低的P600效应,而对于新奇句子,隐喻义和本义违反诱发出基本类似的ERP反应。这些结果表明隐喻义和本义加工存在差异,熟悉性显著影响隐喻义的加工,这种影响在较早语义分析和较晚的语义整合阶段均有体现。     

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。     

Right Hemisphere Activation during Indirect Semantic Priming: Evidence from Event-Related Potentials

Healthy subjects performed a lexical decision task in a semantic priming paradigm while event-related potentials (ERPs) were recorded from 64 channels. Semantic distance between prime and target was varied by including directly, indirectly, and nonrelated word pairs. At centro-parietal electrodes an N400 to nonrelated pairs was elicited bilaterally which was sensitive only to direct, but not to indirect semantic priming. These N400 priming effects were mirrored by the RT data. At inferior fronto-temporal sites directly related words showed ERP priming effects over both hemispheres. However, indirectly related words only elicited ERP priming effects over the right hemisphere. These results support the hypothesis that the right hemisphere semantic system is involved in processing of remote semantic information.     

Not all disfluencies are are equal: The effects of disfluent repetitions on language comprehension

Disfluencies can affect language comprehension, but to date, most studies have focused on disfluent pauses such as er. We investigated whether disfluent repetitions in speech have discernible effects on listeners during language comprehension, and whether repetitions affect the linguistic processing of subsequent words in speech in ways which have been previously observed with ers. We used event-related potentials (ERPs) to measure participants’ neural responses to disfluent repetitions of words relative to acoustically identical words in fluent contexts, as well as to unpredictable and predictable words that occurred immediately post-disfluency and in fluent utterances. We additionally measured participants’ recognition memories for the predictable and unpredictable words. Repetitions elicited an early onsetting relative positivity (100–400 ms post-stimulus), clearly demonstrating listeners’ sensitivity to the presence of disfluent repetitions. Unpredictable words elicited an N400 effect. Importantly, there was no evidence that this effect, thought to reflect the difficulty of semantically integrating unpredictable compared to predictable words, differed quantitatively between fluent and disfluent utterances. Furthermore there was no evidence that the memorability of words was affected by the presence of a preceding repetition. These findings contrast with previous research which demonstrated an N400 attenuation of, and an increase in memorability for, words that were preceded by an er. However, in a later (600–900 ms) time window, unpredictable words following a repetition elicited a relative positivity. Reanalysis of previous data confirmed the presence of a similar effect following an er. The effect may reflect difficulties in resuming linguistic processing following any disruption to speech.     

Can clouds dance? Part 2: An ERP investigation of passive conceptual expansion

Conceptual expansion, one of the core operations in creative cognition, was investigated in the present ERP study. An experimental paradigm using novel metaphoric, nonsensical and literal phrases was employed where individual differences in conceptual knowledge organization were accounted for by using participants’ responses to categorize the stimuli to each condition. The categorization was determined by their judgment of the stimuli on the two defining criteria of creativity: unusualness and appropriateness. Phrases judged as unusual and appropriate were of special interest as they are novel and unfamiliar phrases thought to passively induce conceptual expansion. The results showed a graded N400 modulation for phrases judged to be unusual and inappropriate (nonsense) or unusual and appropriate (conceptual expansion, novel metaphorical) relative to usual and appropriate (literal) phrases. The N400 is interpreted as indexing greater effort to retrieve semantic information and integrate the novel concepts presented through the phrases. Analyses of the later time-window showed an ongoing negativity that was graded in the same manner as the N400. The findings attest to the usefulness of investigating creative cognition using event-related electrophysiology.     

Event-related potentials in phonological matching tasks

Two experiments investigated Event-Related Potentials (ERPs) in matching tasks. In Experiment 1 subjects judged, in separate conditions, whether two words rhymed or were written in the same case. The CNV developing between the two words was larger in the latter task compared to the former at the right temporal site. In the rhyme judgment task, an increased late negativity differentiated the ERPs to nonrhyming words from those that rhymed with the previously presented word. This difference was maximal at the midline and over the right hemisphere. Experiment 2 further investigated ERPs in the rhyme judgment task, increasing memory demands with an extended interstimulus interval (ISI) and varying the number of items subjects had to hold in memory during this period (one vs. three). Irrespective of memory load, CNVs during the ISI were more negative from the left hemisphere, and the ERPs to the rhyming and nonrhyming words showed the same differences as in Experiment 1. The CNV asymmetries are interpreted as being associated with the engagement of lateralized short-term memory processes. The rhyme/nonrhyme differences are possibly related to the “N400” component elicited by semantically incongruous words. Possible reasons for their scalp distribution are discussed.     

Event-related potential sensitivity to acoustic and semantic properties of terminal words in sentences.

This experiment was concerned with the effects of phonologically correct masking on the electrophysiological responses to terminal words of spoken sentences differing in contextual constraint. Two event-related potential (ERP) components, the N400 and N200, were recorded to the terminal words of high and low constraint sentences in four conditions. In the Control condition, subjects (Ss) simply attended to the sentences with no explicit task instructions. In the Semantic condition, Ss were required to listen to the stimuli in order to make semantic judgements about the terminal word of each sentence. The Control+Masking condition was identical to the Control condition except for the simultaneous presentation of a masking stimulus. The Semantic+Masking condition had Ss listening to sentences in the presence of masking with the task of making semantic judgements about the terminal word of each sentence. ERPs were recorded from Fz, Cz, Pz, T3, and T4 in 10 subjects. Amplitudes of both the N200 and the N400 were sensitive to contextual constraint with larger responses elicited by the terminal words of low constraint sentences. In addition to demonstrating the co-occurrence of the N200 and N400, this experiment highlighted a functional separation between the two components. Masking had no statistically significant effect on N200 latency but N400 latency was delayed in the masked conditions relative to those in the unmasked conditions. It is proposed that the N200 and N400 are manifestations of two different processes; the N200 reflects the acoustic/phonological processing of the terminal word while the N400 reflects the cognitive/linguistic processing. The relationship between the N200 recorded in this experiment and the discrimination N200 is discussed.