Interplay between acoustic/phonetic and semantic processes during spoken sentence comprehension: an ERP study

When listening to speech in everyday-life situations, our cognitive system must often cope with signal instabilities such as sudden breaks, mispronunciations, interfering noises or reverberations potentially causing disruptions at the acoustic/phonetic interface and preventing efficient lexical access and semantic integration. The physiological mechanisms allowing listeners to react instantaneously to such fast and unexpected perturbations in order to maintain intelligibility of the delivered message are still partly unknown. The present electroencephalography (EEG) study aimed at investigating the cortical responses to real-time detection of a sudden acoustic/phonetic change occurring in connected speech and how these mechanisms interfere with semantic integration. Participants listened to sentences in which final words could contain signal reversals along the temporal dimension (time-reversed speech) of varying durations and could have either a low- or high-cloze probability within sentence context. Results revealed that early detection of the acoustic/phonetic change elicited a fronto-central negativity shortly after the onset of the manipulation that matched the spatio-temporal features of the Mismatch Negativity (MMN) recorded in the same participants during an oddball paradigm. Time reversal also affected late event-related potentials (ERPs) reflecting semantic expectancies (N400) differently when words were predictable or not from the sentence context. These findings are discussed in the context of brain signatures to transient acoustic/phonetic variations in speech. They contribute to a better understanding of natural speech comprehension as they show that acoustic/phonetic information and semantic knowledge strongly interact under adverse conditions.     

Thinking ahead or not? Natural aging and anticipation during reading

Despite growing evidence of young adults neurally pre-activating word features during sentence comprehension, less clear is the degree to which this generalizes to older adults. Using ERPs, we tested for linguistic prediction in younger and older readers by means of indefinite articles (a’s and an’s) preceding more and less probable noun continuations. Although both groups exhibited cloze probability-graded noun N400s, only the young showed significant article effects, indicating probabilistic sensitivity to the phonology of anticipated upcoming nouns. Additionally, both age groups exhibited prolonged increased frontal positivities to less probable nouns, although in older adults this effect was prominent only in a subset with high verbal fluency (VF). This ERP positivity to contextual constraint violations offers additional support for prediction in the young. For high VF older adults, the positivity may indicate they, too, engage in some form of linguistic pre-processing when implicitly cued, as may have occurred via the articles.     

Career choice and orality

The field of vocational psychology is replete with schemata for the determinants of career choice in adulthood (e.g., A. Roe, The psychology of occupations. New York: Wiley, 1956; D. E. Super, The psychology of careers. New York: Harper &Row, 1957; J. O. Crites, Vocational psychology: The study of vocational behavior and development. New York: McGraw-Hill, 1969). A view not given much weight in empirical research in this area is that of psychoanalytic theory relating career choice to unresolved childhood conflicts and their derivatives. To examine the validity of this psychoanalytic prediction, students' Rorschach protocols were analyzed to yield an index of frustrated oral needs. The students were given decks of careers to rank from most to least preferable. Results showed that the ranking of the oral careers was a function of the Rorschach index of frustrated oral needs for women only but not for men.     

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。     

汉英语言内及语言间重复启动效应的ERP研究

16名母语为汉语的被试参加了一个混合语言的语义判断任务,关键词用汉语和英语呈现,然后重复这些词（语言内或者语言间）。比较词汇第一次呈现、语言内和语言间重复产生的N400波幅的差异发现：汉语和英语的语言内重复启动效应差异不显著,而两种方向的语言间重复启动效应存在不对称性,从英语到汉语的重复启动效应显著大于从汉语到英语的重复启动效应,这与双语表征的非对称模型不尽一致。     

ELECTROPHYSIOLOGICAL CORRELATES OF STIMULUS EQUIVALENCE PROCESSES

Research reported here concerns neural processes relating to stimulus equivalence class formation. In Experiment 1, two types of word pairs were presented successively to normally capable adults. In one type, the words had related usage in English (e.g., uncle, aunt). In the other, the two words were not typically related in their usage (e.g., wrist, corn). For pairs of both types, event‐related cortical potentials were recorded during and immediately after the presentation of the second word. The obtained waveforms differentiated these two types of pairs. For the unrelated pairs, the waveforms were significantly more negative about 400 ms after the second word was presented, thus replicating the “N400” phenomenon of the cognitive neuroscience literature. In addition, there was a strong positive‐tending wave form difference post‐stimulus presentation (peaked at about 500 ms) that also differentiated the unrelated from related stimulus pairs. In Experiment 2, the procedures were extended to study arbitrary stimulus—stimulus relations established via matching‐to‐sample training. Participants were experimentally näive adults. Sample stimuli (Set A) were trigrams, and comparison stimuli (Sets B, C, D, E, and F) were nonrepresentative forms. Behavioral tests evaluated potentially emergent equivalence relations (i.e., BD, DF, CE, etc.). All participants exhibited classes consistent with the arbitrary matching training. They were also exposed also to an event‐related potential procedure like that used in Experiment 1. Some received the ERP procedure before equivalence tests and some after. Only those participants who received ERP procedures after equivalence tests exhibited robust N400 differentiation initially. The positivity observed in Experiment 1 was absent for all participants. These results support speculations that equivalence tests may provide contextual support for the formation of equivalence classes including those that emerge gradually during testing.     

文字加工中的正字法家族效应

正字法家族效应是指正字法邻近词越多, 家族越大, 单词识别越快的一种现象。一般使用词汇判断、语义分类任务、快速命名等实验范式研究。影响家族效应的因素有家族词的频率、材料的语言和家族在单词中的位置等。家族效应表现在150~300ms窗口中的早期成分和更大的N400上。家族效应可能与左大脑半球的不同脑区的的语义激活有关, 也可能与中背外侧前额的执行控制功能有关。家族效应的理论模型主要有：多重标准识别模型、交互激活模型和双通路瀑布式模型等。将来的研究可尝试从实验材料和研究方法等方面进行拓展。     

Electrophysiological Evidence of Different Interpretative Strategies in Irony Comprehension

We explore the hypothesis that induction of holistic or analytic strategies influences comprehension and processing of highly contextualized expressions of ordinary language, such as irony. Twenty undergraduate students were asked to categorize as coherent or incoherent a group of sentences. Each sentence completed a previous story, so that they could be ironical, literal or nonsensical endings. Participants were asked to evaluate whether each sentence was coherent or incoherent. Half of them were initially instructed to consider whether the sentences made sense (holistic condition); the other half were instructed to consider whether the sentences were congruent or incongruent (analytic condition). Behavioral responses and Event Related Potentials were registered during the experiment. Both behavioral and electrophysiological results allow clearly distinguishing between the holistic and the analytic strategies. The fact that the same set of stimuli elicits different ERP waveforms, depending on the strategy with which they are analyzed, suggests that different cognitive processes and different areas of the brain are operating in each case.     

How iconic gestures enhance communication: an ERP study

EEG was recorded as adults watched short segments of spontaneous discourse in which the speaker's gestures and utterances contained complementary information. Videos were followed by one of four types of picture probes: cross-modal related probes were congruent with both speech and gestures; speech-only related probes were congruent with information in the speech, but not the gesture; and two sorts of unrelated probes were created by pairing each related probe with a different discourse prime. Event-related potentials (ERPs) elicited by picture probes were measured within the time windows of the N300 (250-350 ms post-stimulus) and N400 (350-550 ms post-stimulus). Cross-modal related probes elicited smaller N300 and N400 than speech-only related ones, indicating that pictures were easier to interpret when they corresponded with gestures. N300 and N400 effects were not due to differences in the visual complexity of each probe type, since the same cross-modal and speech-only picture probes elicited N300 and N400 with similar amplitudes when they appeared as unrelated items. These findings extend previous research on gesture comprehension by revealing how iconic co-speech gestures modulate conceptualization, enabling listeners to better represent visuo-spatial aspects of the speaker's meaning.     

高度模糊靶字下的N400语义启动效应：词汇加工理论的证据

本研究基于不可识别模糊字词仍能诱发N400的词汇加工理论的假设,让被试对模糊字进行同一字延迟判断,利用脑电技术记录不同模糊程度靶字的认知过程,来探讨N400出现的条件,以阐明N400反映的是词汇加工,还是词汇后加工。实验结果表明：与可识别、轻度模糊汉字一样,不可识别、高度模糊汉字仍然可以诱发N400;这种N400语义启动效应反映了词汇加工过程。