汉语同形歧义词歧义消解的两半球差异

实验探讨汉语同形歧义词(homographs)歧义消解的过程及大脑两半球的差异。被试为华中科技大学96名大学生,实验采用词汇判断任务。句子语境呈现在被试的视野中央,探测词在SOA(stimulus onset asynchronism)为100毫秒或400毫秒时呈现在左视野或右视野。结果发现,(1)当SOA为100毫秒时,在左视野(右半球)上,与语境一致的同形歧义词的主要意义得到激活,与语境不一致的次要意义也有一定程度的激活。在右视野(左半球)上,只有与语境一致的同形歧义词的主要意义得到激活。(2)当SOA为400毫秒时,在左、右视野(两半球)上,与语境一致的同形歧义词的主要意义和次要意义都得到激活。结果表明,大脑左半球对汉语歧义词的歧义消解具有一定的优势,语境敏感模型可以较好地解释本实验的结果。     

词汇识别中歧义词素语义加工:ERP研究

结合掩蔽启动范式和ERP技术,利用歧义词素的加工,本研究探讨了歧义词素语义的激活。实验采用3×2两因素被试内设计,歧义词素两含义互为启动刺激和目标刺激,两变量分别为启动词类型(歧义词素含义1 vs.含义2 vs.无关词)和目标词类型(歧义词素含义1 vs.含义2)。行为结果发现启动词类型和目标词类型存在交互作用,即只有当共享词素同形同义的情况下,目标词的加工才可能被启动,共享词素同形不同义时并没有产生启动效应。ERP结果进一步肯定了行为结果,在N250和N400两个脑电成分上都发现了启动类型和目标类型交互作用有关的效应,当启动词和目标词共享词素同形同义时,同时引发了N250和N400的变化;当共享词素同形不同义时,时程分析时虽然也发现了N250的变化,但是N250的效应较小,小于同形同义所引发的N250效应,持续时间也较短。实验结果说明,在词汇识别中歧义词素语义可以激活,并对目标词汇加工的早期加工阶段发挥作用。     

句子语境中汉语词类歧义词的意义激活

以单字词为实验材料 ,采用跨通道启动真假字判断任务 ,在句子语境中考察汉语词类歧义词不同意义激活的特点。被试为 134名北京师范大学本科学生。实验时向被试听觉呈现含有歧义词的句子 ,且句子语境分别支持歧义词的主要或次要意义 ,以不同的ISI分别呈现与歧义词两种意义有关的视觉目标词。结果发现 ,当探测目标词在最短的ISI出现时 ,与语境支持的意义有关的目标词反应时较短 ,表明语境在歧义词加工早期促进合适意义的激活 ,同时限制不合适意义的激活。实验数据支持相互作用理论     

词汇歧义消解的脑机制

词汇歧义是语言歧义的一种, 词汇歧义消解受到相对意义频率和语境的影响。半视野研究发现大脑两半球都能在词汇歧义消解过程中根据语境信息选择性地激活歧义词的恰当意义、抑制不恰当意义, 其中左半球的语义选择功能更强; 脑损伤研究发现大脑左、右半球损伤都会导致词汇歧义消解中语义选择障碍, 词汇歧义消解需要大脑两半球的联合作用; 神经成像研究进一步发现额叶与颞叶共同支持词汇歧义消解, 歧义词的恰当意义的选择是由额下回执行的, 语义整合加工是由颞叶负责的。     

速示条件下蒙古族、汉族儿童对文字辨读率与反应时的对比研究

本研究采用半视野速示术对蒙古族和汉族儿童进行了辨读蒙汉文字反应时的测定.结果表明,两民族儿童辨读单汉字时右视野(左脑半球)反应时均短于左视野(右脑半球),认知准确度上右视野亦优于左视野,蒙古族儿童两视野反应时差异达到了显着性水平.蒙古族儿童辨读蒙文单字词时右视野反应时明显短于左视野.认为蒙古族儿童言语功能侧化于左半球的程度甚于汉族儿童.     

汉语同音歧义词歧义消解的过程及其抑制机制

两个实验分别采用词语境或句子语境探讨汉语同音歧义词(homophones)歧义消解的过程。被试为112名大学生。实验通过有计划地比较不同语境偏向条件下有关探测词和无关探测词之间反应时的差异,从而揭示汉语同音歧义词消解过程中,对其适当意义激活以及对其不适当意义抑制的时间进程。两个实验的结果都表明：在同音歧义词加工的早期,语境的作用主要表现为抑制歧义词不适当意义,阻止其激活;随后,语境促进了歧义词适当意义的激活。另外,相对意义频率在同音歧义词歧义消解过程中有其影响。     

中文阅读中因果与转折关系理解差异的实验研究

采用移动窗口阅读技术和探测技术探讨大学生中文阅读过程中对因果与转折关系的理解差异。实验一在句子层面考察因果和转折关系的理解差异,结果发现被试阅读转折句的时间显著长于因果句,但对两种句子中探测词的反应时没有差异。实验二运用探测技术从篇章层面进一步探讨两种关系的理解差异。结果发现,转折关系条件下被试对探测词的反应时显著慢于因果关系条件下。实验结果表明,无论在句子层面还是在篇章层面,被试对转折关系的表征都难于因果关系的表征。     

汉语言语产生中语音、字形启动的位置效应

以起始掩蔽启动效应(the Masked Onset Priming Effect, 简称MOP效应)为研究背景, 通过3个实验, 考察了语音和字形在MOP效应产生中的作用, 以及在汉语单字词产生中语音、字形启动的位置效应。实验1表明, 在汉语单字词的产生中, 语音启动的位置效应显著, 声母启动的效应量显著大于韵母启动的效应量, 与拼音文字研究得到的MOP效应类似, 说明在MOP效应中至少包含有语音效应。汉字单字词语音编码的最小单位是音位, 而且具有从左到右序列加工的特点, 支持言语产生的“音节临时形成论”。实验2表明, 与目标字左、右部件相同的启动刺激均能促进掩蔽启动范式中的命名反应, 被试对与启动字的右部件相同的目标字的反应显著快于对与启动字的左部件相同的目标字的反应, 与起始掩蔽启动效应的假设相反, 说明在MOP效应中不包含有字形的作用, 却发现了汉字单字词特有的命名的字形位置效应：右部件启动的效应量大于左部件启动的效应量。实验3采用图-词干扰范式对汉字左、右部件的启动效应做了进一步的探讨, 仍然发现汉字右部件启动的效应量显著大于汉字左部件启动的效应量。整个研究表明, MOP效应是单纯的语音效应, 并不包含有字形的作用; MOP效应产生于言语产生中的语音编码阶段, 支持言语计划理论的观点。     

汉语名词、动词和动名兼类词语义加工的偏侧化现象——来自ERP的研究

将ERP技术和半视野技术相结合,采用词汇判断任务,对汉语名词、动词和动名兼类词在左脑和右脑中的加工机制进行了考察。实验结果显示,名词和动词的N400仅在左视野/右脑存在差异,名词和动词的N400在左视野/右脑和右视野/左脑中都比偏（动）和偏（名）更负。不同词类的LPC在右视野/左脑中没有显著差异;偏（名）和偏（动）的LPC在左视野/右脑中比名词和动词更正。实验结果表明,在没有语境条件下,汉语名词和动词的差异主要在具体性上,动名兼类词体现出不同于名词、动词的加工机制。     

重复启动作业中词的语义透明度的作用

用词素重复启动的方法考察合成词的心理表征。目标刺激为２４个语义透明度词、２４个不透明词以及４８个非词（都是两个字）。启动刺激有５种：（１）目标词本身,（２）目标词的第一词素,（３）目标词的第二词素,（４）由目标词的两个词素颠倒后形成的非词,（５）包含目标词的一个词素的非词。启动刺激的呈现时间是１００毫秒,随后是目标刺激４００毫秒。被试的任务是尽快准确地按键判断目标刺激是否是一个词。研究发现,（２）、（３）、（５）条件下的重复启动中,透明度表现出显著的效应：透明词的启动量显著大于不透明词。结果支持合成词的表征受语义透明度的影响,透明词和不透明词的词素和整词在心理表征中的关系可能不同：前者是一种兴奋性的连接,后者是一种抑制性的连接。     

Qualitative hemispheric differences in semantic category matching.

A unilateral category matching task with words as stimuli was employed to investigate semantic processing in the right and left hemispheres (RH, LH). An overall right visual field (RVF)/LH dominance was observed and performances were better than chance, also in the left visual field (LVF)/RH. A qualitative analysis of reaction times with individual differences multidimensional scaling (INDSCAL) revealed that LVF/RH INDSCAL solutions were significantly more differentiated in structure than RVF/LH solutions in terms of number and size of dimensions. These findings support a depth of activation hypothesis of hemispheric processing, with the LH rapidly and focally and the RH slowly and diffusely activating the semantic network.     

Quantitative and Qualitative Hemispheric Asymmetry for Processing Japanese Kana

Native Japanese speakers identified three-letter kana stimuli presented to the left visual field and right hemisphere (LVF/RH), to the right visual field and left hemisphere (RVF/LH), or to both visual fields and hemispheres simultaneously (BILATERAL trials). There were fewer errors on RVF/LH and BILATERAL trials than on LVF/RH trials. Qualitative analysis of error patterns indicated that there were many fewer errors of first-letter identification than of last-letter identification, suggesting top-to-bottom scanning of the kana characters. In contrast to similar studies presenting nonword letter trigrams to native English speakers, qualitative error patterns were identical for the three visual field conditions. Taken together with the results of earlier studies, the results of the present experiment indicate that the ubiquitous RVF/LH advantage reflects a left-hemisphere superiority for phonetic processing that generalizes across specific languages. At the same time, qualitative aspects of hemispheric asymmetry differ from one language to the next and may depend on such things as the way in which individual characters map onto the pronunciation of words and nonwords.     

Mixing metaphors in the cerebral hemispheres: what happens when careers collide?

Are processes of figurative comparison and figurative categorization different? An experiment combining alternative-sense and matched-sense metaphor priming with a divided visual field assessment technique sought to isolate processes of comparison and categorization in the 2 cerebral hemispheres. For target metaphors presented in the right visual field/left cerebral hemisphere (RVF/LH), only matched-sense primes were facilitative. Literal primes and alternative-sense primes had no effect on comprehension time compared to the unprimed baseline. The effects of matched-sense primes were additive with the rated conventionality of the targets. For target metaphors presented to the left visual field/right cerebral hemisphere (LVF/RH), matched-sense primes were again additively facilitative. However, alternative-sense primes, though facilitative overall, seemed to eliminate the preexisting advantages of conventional target metaphor senses in the LVF/RH in favor of metaphoric senses similar to those of the primes. These findings are consistent with tightly controlled categorical coding in the LH and coarse, flexible, context-dependent coding in the RH.     

Hemispheric differences in processing handwritten cursive

Hemispheric asymmetry was examined for native English speakers identifying consonant-vowel-consonant (CVC) non-words presented in standard printed form, in standard handwritten cursive form or in handwritten cursive with the letters separated by small gaps. For all three conditions, fewer errors occurred when stimuli were presented to the right visual field/left hemisphere (RVF/LH) than to the left visual field/right hemisphere (LVF/RH) and qualitative error patterns indicated that the last letter was missed more often than the first letter on LVF/RH trials but not on RVF/LH trials. Despite this overall similarity, the RVF/LH advantage was smaller for both types of cursive stimuli than for printed stimuli. In addition, the difference between first-letter and last-letter errors was smaller for handwritten cursive than for printed text, especially on LVF/RH trials. These results suggest a greater contribution of the right hemisphere to the identification of handwritten cursive, which is likely related visual complexity and to qualitative differences in the processing of cursive versus print.     

Facilitative orthographic neighborhood effects: the SERIOL model account

A large orthographic neighborhood (N) facilitates lexical decision for central and left visual field/right hemisphere (LVF/RH) presentation, but not for right visual field/left hemisphere (RVF/LH) presentation. Based on the SERIOL model of letter-position encoding, this asymmetric N effect is explained by differential activation patterns at the orthographic level. This analysis implies that it should be possible to negate the LVF/RH N effect and create an RVF/LH N effect by manipulating contrast levels in specific ways. In Experiment 1, these predictions were confirmed. In Experiment 2, we eliminated the N effect for both LVF/RH and central presentation. These results indicate that the letter level is the primary locus of the N effect under lexical decision, and that the hemispheric specificity of the N effect does not reflect differential processing at the lexical level.     

Effects of Output Order on Hemispheric Asymmetry for Processing Letter Trigrams

Observers identified consonant–vowel–consonant trigrams with the letters arranged vertically by pronouncing the stimulus (treating the bottom letter as the first letter) and spelling it from bottom to top. On each trial, the trigram was presented to the left visual field/right hemisphere (LVF/RH), to the right visual field/left hemisphere (RVF/LH), or to both visual fields simultaneously (BILATERAL trials). Quantitative and qualitative visual field differences were identical to those found when observers used a more natural response output order, treating the top letter of the trigram as the first letter. The results suggest that, regardless of output order, attention is distributed across the three letters in a relatively slow, top-to-bottom fashion on LVF/RH and BILATERAL trials, whereas attention is distributed more rapidly and evenly across the three letters on RVF/LH trials.     

Priming nouns and verbs: differential influences of semantic and grammatical cues in the two cerebral hemispheres

The current experiment investigated how sentential form-class expectancies influenced lexical-semantic priming within each hemisphere. Sentences were presented that led readers to expect a noun or a verb and the sentence-final target word was presented to one visual field/hemisphere for a lexical decision response. Noun and verb targets in the semantically related condition were compared to an unrelated prime condition, which also predicted part of speech but did not contain any lexical-semantic associates of the target word. The semantic priming effect was strongly modulated by form-class expectancy for RVF/LH targets, for both nouns and verbs. In the LVF/RH, semantic priming was obtained in all conditions, regardless of whether the form-class expectancy was violated. However, the nouns that were preceded by a noun-predicting sentence showed an extremely high priming value in the LVF/RH, suggesting that the RH may have some sensitivity to grammatical predictions for nouns. Comparisons of LVF/RH priming to calculations derived from the LSA model of language representation, which does not utilize word order, suggested that the RH might derive message-level meaning primarily from lexical-semantic relatedness.     

Understanding metaphoric sentences in the two cerebral hemispheres

Previous studies indicate that the right hemisphere (RH) has a unique role in maintaining activation of metaphoric single word meanings. The present study investigated hemispheric asymmetries in comprehending metaphoric word meanings within a sentence context. Participants were presented with incomplete priming sentences followed by (literally) true, false, or metaphoric lateralized target words and were asked to decide whether each sentence is literally true or false. Results showed that responses to metaphoric sentences were slower and less accurate than to false sentences when target words were presented to the right visual field (RVF)-LH as well as to the left visual field (LVF)-RH. This suggests that the understanding of lexical metaphors within a sentence context involves LH as well as RH processing mechanisms and that the role of each hemisphere in processing nonliteral language is flexible and may depend on the linguistic task at hand.     

Sentence and word outline shape as co-primes for target words presented to the two visual hemifields

A lexical decision experiment tested visual field stimulation of word targets after priming the central visual field by the target word outline shape and/or an incomplete sentence. In general, RT was shorter and accuracy better for target words presented to the RVF. Responses were quicker and more accurate to target words presented to either visual hemifield after priming by either a congruent incomplete sentence or a congruent word outline shape (WOS). However, the joint effect of WOS and an incomplete sentence as co-primes was different when the succeeding word target appeared in the RVF than when it appeared in the LVF. While a congruent WOS and incomplete sentence acting as co-primes reduced RT to LVF targets orthogonally. the two variables operated interactively as co-primes on target words presented to the RVF.