Electrophysiological analysis of stimulus variables in equivalence relations

Recently, electrophysiological measures have been used to evaluate the functional overlap between semantic relations and laboratory-defined equivalence relations with abstract stimuli. Several studies using semantic judgment procedures have shown that accompanying EEG-measured neural activity for stimulus pairs from equivalence classes is very similar to that of word pairs from participants' native language. However, those studies often included pronounceable elements (e.g., written nonsense syllables) as at least one member of the experimentally defined classes. The present study conducted EEG studies that contrasted classes with and without such elements. Two groups of undergraduate students completed a matching-to-sample procedure to establish 3 4-member equivalence classes. For Group 1, samples and comparisons were pronounceable pseudowords and abstract figures. For Group 2, the matching-to-sample stimuli were abstract figures only. EEG data recorded during the semantic judgment tasks showed waveform patterns compatible with prior studies of semantic relations in Group 1 but not in Group 2.     

自然数码奇象记忆法记忆复杂数字的神经机制

本研究采用学习-再认范式和复杂数字记忆材料,考察自然数码奇象记忆法相对于机械记忆法在记忆提取上的优势及神经机制。行为结果表明,自然数码奇象记忆法比机械记忆法的再认准确率更高。事件相关电位分析结果显示,再认提取阶段奇象记忆条件下诱发的N400和N700波幅显著更低,这说明奇象记忆提取更容易。在自然数码奇象记忆条件下,正确再认旧数字诱发的前额区、左顶枕叶区及中顶枕叶区N700成分与使用自然数码奇象记忆有关。本研究表明,采用自然数码奇象记忆可以减少或跨越语义加工,从而提高个体对材料的记忆效率。     

FN400和LPC对熟悉性和回想的特异性指向分析

双加工理论认为熟悉性和回想是情景记忆的两个独立过程,其重要证据是ERP研究中FN400和LPC可以分别指示熟悉性和回想。但也有研究证明FN400是概念启动和熟悉性共同作用的结果,而LPC也不能准确的反映回想加工,因此,将其作为双加工理论证据的可靠性需进一步讨论。未来需进一步明确概念启动和熟悉性影响FN400的前提条件,并在提高生态效度和控制额外变量的同时明晰LPC的指向性,同时探究熟悉性和回想在再认过程中的具体作用方式。     

汉语复合词视觉识别的时间进程：基于同形语素的行为与ERP证据

基于同形语素抑制效应, 本研究探讨了汉语复合词视觉识别中的形音义激活进程。结果发现：(1) 同形异音、同形同音、相同条件相对于控制条件都产生了语素启动效应; (2) 在P2、晚期N400成分上, 同形同音条件与控制条件更为接近, 但与同形异音及相同条件差别显著; (3) 在早期N400成分上, 同形同音条件与相同条件更为接近, 但与同形异音条件差别显著。研究表明, 汉语复合词的视觉识别的早期阶段可能为基于词位的形态-正字法加工, 字形匹配与音位信息是首要影响因素, 但语义是否介入仍未可知; 而晚期阶段则可能为基于词条的形态-语义加工, 主要涉及语义竞争与选择。本研究结果支持了McClelland等学者提出的“平行分布加工模型”。     

Effects of speed of word processing on semantic access: the case of bilingualism

Bilingual speakers generally manifest slower word recognition than monolinguals. We investigated the consequences of the word processing speed on semantic access in bilinguals. The paradigm involved a stream of English words and pseudowords presented in succession at a constant rate. English-Welsh bilinguals and English monolinguals were asked to count the number of letters in pseudowords and actively disregard words. They were not explicitly told that pairs of words in immediate succession were embedded and could either be semantically related or not. We expected that slower word processing in bilinguals would result in semantic access indexed by semantic priming. As expected, bilinguals showed significant semantic priming, indexed by an N400 modulation, whilst monolinguals did not. Moreover, bilinguals were slower in performing the task. The results suggest that bilinguals cannot discriminate between pseudowords and words without accessing semantic information whereas monolinguals can dismiss English words on the basis of subsemantic information.     

Dissociating linguistic and non-linguistic gesture processing: electrophysiological evidence from American Sign Language

A fundamental advance in our understanding of human language would come from a detailed account of how non-linguistic and linguistic manual actions are differentiated in real time by language users. To explore this issue, we targeted the N400, an ERP component known to be sensitive to semantic context. Deaf signers saw 120 American Sign Language sentences, each consisting of a “frame” (a sentence without the last word; e.g. BOY SLEEP IN HIS) followed by a “last item” belonging to one of four categories: a high-close-probability sign (a “semantically reasonable” completion to the sentence; e.g. BED), a low-close-probability sign (a real sign that is nonetheless a “semantically odd” completion to the sentence; e.g. LEMON), a pseudo-sign (phonologically legal but non-lexical form), or a non-linguistic grooming gesture (e.g. the performer scratching her face). We found significant N400-like responses in the incongruent and pseudo-sign contexts, while the gestures elicited a large positivity.     

A neurally plausible parallel distributed processing model of event-related potential word reading data

The Parallel Distributed Processing (PDP) framework has significant potential for producing models of cognitive tasks that approximate how the brain performs the same tasks. To date, however, there has been relatively little contact between PDP modeling and data from cognitive neuroscience. In an attempt to advance the relationship between explicit, computational models and physiological data collected during the performance of cognitive tasks, we developed a PDP model of visual word recognition which simulates key results from the ERP reading literature, while simultaneously being able to successfully perform lexical decision—a benchmark task for reading models. Simulations reveal that the model’s success depends on the implementation of several neurally plausible features in its architecture which are sufficiently domain-general to be relevant to cognitive modeling more generally.     

Decomposing animacy reversals between agents and experiencers: An ERP study

The present study aimed to refine current hypotheses regarding thematic reversal anomalies, which have been found to elicit either N400 or - more frequently - “semantic-P600” (sP600) effects. Our goal was to investigate whether distinct ERP profiles reflect aspectual-thematic differences between Agent-Subject Verbs (ASVs; e.g., ‘to eat’) and Experiencer-Subject Verbs (ESVs; e.g., ‘to love’) in English. Inanimate subject noun phrases created reversal anomalies on both ASV and ESV. Animacy-based prominence effects and semantic association were controlled to minimize their contribution to any ERP effects. An N400 was elicited by the target verb in the ESV but not the ASV anomalies, supporting the hypothesis of a distinctive aspectual-thematic structure between ESV and ASV. Moreover, the N400 finding for English ESV shows that, in contrast to previous claims, the presence versus absence of N400s for this kind of anomaly cannot be exclusively explained in terms of typological differences across languages.     

Number of sense effects of Chinese disyllabic compounds in the two hemispheres

The current study manipulated the visual field and the number of senses of the first character in Chinese disyllabic compounds to investigate how the related senses (polysemy) of the constituted character in the compounds were represented and processed in the two hemispheres. The ERP results in experiment 1 revealed crossover patterns in the left hemisphere (LH) and the right hemisphere (RH). The sense facilitation in the LH was in favor of the assumption of single-entry representation for senses. However, the patterns in the RH yielded two possible interpretations: (1) the nature of hemispheric processing in dealing with sublexical sense ambiguity; (2) the semantic activation from the separate-entry representation for senses. To clarify these possibilities, experiment 2 was designed to push participants to a deeper level of lexical processing by the word class judgment. The results revealed the sense facilitation effect in the RH. In sum, the current study was in support of the single-entry account for related senses and demonstrated that two hemispheres processed sublexical sense ambiguity in a complementary way.     

高功能自闭症儿童不同常规度转喻加工的发展：来自ERP的证据

采用ERP技术考察了6~11岁高功能自闭症（HFA）儿童常规和新奇转喻的认知加工过程及发展轨迹。结果显示,6~8岁HFA组和典型发展（TD）组加工常规和新奇转喻的N400波幅无差异,未出现常规度效应,其波幅与错误句也无差异。9~11岁HFA组对新奇转喻N400波幅负于常规转喻,出现常规度效应,常规转喻N400波幅异于错误句,9~11岁TD组常规和新奇转喻均异于错误句。6~8岁HFA组对常规转喻N400差异波负于9~11岁,6~8岁TD组对常规和新奇转喻均负于9~11岁。HFA组转喻N400波幅均负于TD组。结论：HFA儿童常规和新奇转喻的加工较TD儿童存在缺陷。从6岁到11岁,HFA儿童常规转喻加工随年龄增长显著提高,新奇转喻则未出现明显变化,较之常规转喻,新奇转喻的加工尤为困难。