正常维-汉双语者汉语事件相关电位N400的神经源分布研究

目的基于视觉通道以句子为刺激材料,通过对匹配与不匹配两种语义条件下事件相关电位N400差异波的研究,探讨以汉语为第二语言的维吾尔语-汉语双语者汉语认知的神经源分布特点。方法利用事件相关电位(ERP)技术对21名纯右利手、平均年龄(20.3±2.1)岁的女性健康维-汉双语被试,以N400差异波的脑电地形图及差异波两半球对应部位电极的波幅为观测指标进行研究。结果脑电地形图分布可见,N400在300 ms首先激活右中央上区和左额区。315 ms时激活左中央区。330 ms时激活顶枕区、左颞前区。345 ms时除前额及左颞区、右后颞外的大脑各区广泛激活。360 ms时上述各区仍处于激活态,以中央区、顶区较为显著。390 ms时,右中央区仍激活;两半球波幅显著性检验发现,除中央区两半球差异有统计学意义(P<0.05)外,额区、颞区、顶区、枕区差异均无统计学意义。结论维-汉双语者其汉语语义加工模式不同于汉语母语者,也不完全同于其母语从属的拼音文字特点;维、汉双语者汉语语义的处理过程是大脑左右半球协同作用的结果,应以其自身特点指导民族病人的临床实践。     

汉语及图片语义加工机制的fMRI研究

目的利用功能磁共振成像(fMRI)技术探讨汉字及图片语义加工的脑机制。方法对13名正常青年受试者进行视觉方式呈现汉字及图片语义辨别任务的fMRI扫描,采用AFNI软件进行数据分析和脑功能区活动图像。结果fMRI显示两种任务均激活了左侧顶下小叶、额中回、额下回、右侧小脑及双侧梭状回、舌回、枕中回、枕下回、辅助运动区。其中左侧顶下小叶、额中回及双侧枕中回、梭状回在图片语义辨别任务激活明显强于汉字任务,有显著性差异(P<0.05)。结论汉字及图片语义的脑加工均存在偏侧化现象,图片语义的脑处理有更多的脑活动参与完成。     

汉字情景记忆时皮层定位的fMRI研究

目的探讨用功能磁共振成像(fMRI)检测汉字情景记忆时皮层定位的价值及皮层定位的双侧不对称性.方法 10名健康右利手成人,以高频双字汉字作为刺激任务,行全脑fMRI,确定激活皮层的定位.结果汉字情景记忆时双侧多个脑区有激活,但两侧激活脑区不完全对称,编码加工时主要激活脑区为左侧纹外区和左侧颞叶梭状回,而提取加工时左侧顶叶楔前叶、左侧前额叶背外侧显著激活.结论汉字情景记忆时左右大脑半球激活区存在不对称性,fMRI可对此种功能皮层进行准确定位.     

应用事件相关电位技术研究词汇识别中汉字正字法的作用

目的:使用事件相关电位技术考察人脑在视觉通道下汉语词汇识别中汉字正字法的作用。方法:实验于2004-04/07在徐州师范大学语言研究所事件相关电位实验室完成。①实验对象及分组:选择16名大学生(8女,8男,18～22岁)经书面同意后进行词汇判断实验。单音节词汇判断为测试组,双音节词汇判断为对照组。②实验语料:选自1986年北京语言学院出版社出版的《现代汉语频率词典》日常生活常用语部分,选词包括单音节词和双音节词。单音节假词通过调换真字相应位置的一个部件得到,双音节假词通过调换真词中一个音节得到。真词和假词的笔划数无显著差异。刺激词共264个,每个刺激呈现时间为200ms,刺激间隔在2.0￣2.5s。③实验过程:分两个序列,受试者被要求在保证反应正确的前提下尽可能迅速地进行按键操作。④实验评估:采用NeuroScan公司64导电极帽10/20系统记录脑电,离线分析处理事件相关电位数据。结果:名受试者进入结果分析。①行为学数据结果:真词的反应时均显著短于假词(P<0.05),真词的正确率均显著高于假14词(P<0.05)。②脑电数据结果:N400的波峰值假词显著低于真词(P<0.05),但只有测试组中N400的波峰单音节假词迟于真词出现;测试组中,560～660ms时间窗口内P600的平均幅值单音节假词显著高于真词(P<0.05),对照组中600～700ms时间窗口内P600的平均幅值双音节假词显著高于真词(P<0.05)。③假词减真词的差异波分析结果:测试组和对照组中均出现Nd400,Pd600,但Pd250却只在前者出现,且主要在额中央区、中央顶区分布;对照组中Nd400波幅值较小,脑区分布范围也较大,主要分布在双侧顶中央区、右半球颞顶区,测试组的Nd400主要在右半球颞顶枕区分布;测试组Pd600波幅值较大,脑区分布范围较广,主要分布于右半球中央及顶枕区,对照组则主要在右半球顶枕区分布。结论:①在视觉通道的汉语词汇判断实验中,差异波分析可观察人脑在词汇识别中正字法的作用。②Pd250是视觉词汇识别中汉字正字法作用的特异性成分,表明汉字正字法作用在刺激词呈现约250ms后开始体现,该成分可能反映了视觉词汇识别中人脑对汉字部件组合规则和汉字拼读规则的加工过程。③双音节词汇判断中Nd400可能反映了视觉词汇识别中人脑对汉字部件语义组配的加工过程;Pd600则可能反映了人脑重新分析汉字部件语义组配的加工过程。     

脑电监测在癫痫患者间期皮层和皮层下高代谢灶的判读中的应用

目的　探讨癫痫患者无临床发作情况下18F氟脱氧葡萄糖(18Ffluorodeoxyglucose,18FFDG)正电子发射计算机断层 (positron emission tomography, PET)脑显像呈现高代谢时脑电监测的应用价值。 方法　对北京协和医院2008年1月至2014年3月共3例无临床发作的间期情况下18FFDG PET脑显像呈现皮层或皮层下高代谢的癫痫患者, 静脉注射安定抑制皮层放电，在脑电监测确认无皮层异常放电时复查18FFDG PET脑显像，并对比两次显像结果。结果　病例1为颞叶癫痫患者，在无临床发作时18FFDG PET显像除发现右颞低代谢外，右额部分皮层及同侧基底节、丘脑及左侧小脑局灶代谢增高。脑电监测下抑制皮层放电后的18FFDG PET显像示原额叶皮层及同侧基底节、丘脑、对侧小脑高代谢灶消失。表明该患者上述高代谢灶为颞叶外皮层潜在致痫灶亚临床放电所致，同时证实了致痫灶与同侧基底节丘脑、对侧小脑之间的神经传导。此例改变了先前单纯前颞叶切除术的临床决策。病例2的间期18FFDG PET显像发现右侧大片额叶皮层高代谢，脑电监测下抑制临床下放电后，原皮层高代谢仍存在，原同侧基底节、对侧小脑的高代谢已不明显,证实皮层存在高代谢的基础病变(炎症)，而基底节丘脑为继发功能改变，确定了病变性质及范围。病例3为颞叶癫痫患者，临床及脑电无法确定癫痫起源部位，磁共振成像未见明显异常。18FFDG PET显像在无临床发作的情况下左侧海马区呈高代谢，脑电监测下在明确的间期状态复查18FFDG PET脑显像，左侧海马区仍为高代谢。提示该部位存在基础病变(肿瘤),帮助临床确定手术部位。 结论　癫痫患者无临床发作情况下18FFDG PET显像呈现高代谢图像时，在脑电监测下确认绝对的间期状态时复查18FFDG PET显像，有助于分析高代谢的病因及明确病变范围，帮助作出临床决策。     

正常人不同刺激野ERP及其法医学价值研究

目的研究正常人不同刺激野电生理反应及头皮分布,进一步探讨不同视野缺损时视觉信息处理的特征与差别。方法本研究分别对30名正常视功能被试进行不同刺激野刺激,同时记录其脑电反应。结果事件相关电位（ERP）早期成分显示：与上视野缺损相比,下视野缺损引起广泛脑区N1和枕颞部P1潜伏期显著延长;此外,上视野缺损较下视野缺损诱发出较小P1,而N1振幅表现为上下视野间相似。ERP晚期成分显示：与下视野缺损对比,上视野缺损引起广泛脑区N2和左半球中央顶区P3潜伏期显著延长,以及较小N2,而P3振幅在上下视野间无差异。结论ERP结果提示,下视野缺损主要引起ERP早期成分P1和N1潜伏期的延长,而上视野缺损主要引起ERP晚期成分N2和P3潜伏期的延长,以及P1和N2振幅的降低。     

昏迷患者P300电位的改变

事件相关电位 (ｅｖｅｎｔ ｒｅｌａｔｅｄｐｏｔｅｎｔｉａｉｓ ,ＥＲＰ)检测技术可在无创条件下检测出与大脑认知活动有关的脑电位变化[1] ,根据所测的ＥＲＰ各成份 ,尤其是内源性成份Ｐ30 0电位 ,可分析判断人脑信息 ,被看做是观察大脑功能活动的窗口 ,是近年来神经电生理研究中一个很活跃的新领域。对那些脑损害严重 ,意识丧失或不能进行配合检查的患者 ,试图通过Ｐ30 0电位的改变 ,进行评估其大脑认知功能受损害程度的可行性具有特殊意义[2 ] 。本实验主要是了解昏迷患者事件相关电位中Ｐ30 0电位的改变 ,以及与睡眠状态中Ｐ30 0电位改…     

慢性乙醇中毒性周围神经病的脑部电生理学研究

目的分析慢性乙醇中毒性周围神经病(CAPN)患者的脑功能损害。方法以CAPN患者184例为研究组,同期健康志愿者169例为对照组。应用神经电生理学技术,分析脑听觉诱发电位(BAEP)、事件相关电位;应用脑电监测非线性分析技术,分析脑电信号的关联维及近似熵。结果①BAEP:CAPN组在波Ⅰ~Ⅶ的潜伏期均显著性延长(t=7.290~35.217,P0.01),波幅均显著性降低(t=5.567~18.389,P0.01)。②ERPs:CAPN组在事件相关电位各成分的潜伏期均显著性延长(t=9.086~29.824,P0.01),波幅均显著性降低(t=20.139~37.989,P0.01)。③脑区ApEn:CAPN组在额区、颞区、顶区、枕区的脑电信号近似熵均显著性偏低(t=18.318~33.905,P0.01)。④全脑D_2及ADEn:CAPN组全脑关联维(t=5.826,P=0.0001)、近似熵(t=2.961,P=0.0033)均显著性偏低。结论 CAPN患者在中枢神经系统临床表现出现前,已经存在脑皮层及皮层下功能减退,脑电生理学技术有助于其早期诊断。     

不同言语加工水平受损的汉语失语症患者治疗前后的事件相关电位变化

目的:本研究采用事件相关电位(ERPs)技术考察不同类型失语患者治疗前后的ERP脑电变化。方法:根据"汉语失语症心理语言评价"得分结果,把1例归为语义损伤为主和3例患者归为词汇通达障碍。另1例患者因不能理解动作指令,不能理解简单句子,归为语义损伤组,采用ERPs作为技术手段,实验任务为延迟命名,观察患者的治疗前后的脑电情况,用于实验的图片分为训练组图片和非训练组图片,记录15例健康人的脑电图作为对照。结果:2例语义损伤的患者治疗后波幅变化出现在400ms以前的时间窗,3例找词困难的患者治疗后波幅变化出现在400ms前后或之后的时间窗,波幅变化不仅出现在训练过的图片,也出现在非训练组语义相关的图片,左右半球间有不同形式的波幅变化(P1和P3),训练组图片与非训练组图片也有不同形式的波幅变化(P5)。结论:ERPs可作为探讨汉语失语症病态内部语言的过程,辅助探讨失语症恢复的机制以及与语言治疗的关系。     

癫痫手术术中皮层脑电监测的护理

目的 总结术中皮层脑电监测的护理经验.方法 术中使用皮层电极对病灶及相应部位皮层脑电监测,确定癫痫灶的位置及范围,显微镜下行癫痫灶切除,切除后再次进行皮层脑电图监测.结果 本组34例在监测中均有痫样放电,患者术后8～12 d恢复顺利,无并发症.结论 术中皮层脑电监测对癫痫的手术治疗十分重要,对于术前定位的病例,可进一步...     

Overlap and dissociation of semantic processing of Chinese characters, English words, and pictures: evidence from fMRI

The functional anatomy of Chinese character processing was investigated using fMRI. Right-handed Mandarin-English bilingual participants made either semantic or perceptual size judgements with characters and pictures. Areas jointly activated by character and picture semantic tasks compared to size judgement tasks included the left prefrontal region (BA 9, 44, 45), left posterior temporal, left fusiform, and left parietal regions. Character processing produced greater activation than picture processing in the left mid and posterior temporal as well as left prefrontal regions. The lateral occipital regions were more active during picture semantic processing than character semantic processing. A similar pattern of activation and contrasts was observed when English words and pictures were compared in another set of bilingual participants. However, there was less contrast between word and picture semantic processing than between character and picture processing in the left prefrontal region. When character and word semantic processing were compared directly in a third group, the loci of activation peaks was similar in both languages but Chinese character semantic processing was associated with a larger MR signal change. The semantic processing of Chinese characters, English words, and pictures activates a common semantic system within which there are modality-specific differences. The semantic processing of Chinese characters more closely resembles English words than pictures.     

A meta-analysis of fMRI studies on Chinese orthographic, phonological, and semantic processing

A growing body of neuroimaging evidence has shown that Chinese character processing recruits differential activation from alphabetic languages due to its unique linguistic features. As more investigations on Chinese character processing have recently become available, we applied a meta-analytic approach to summarize previous findings and examined the neural networks for orthographic, phonological, and semantic processing of Chinese characters independently. The activation likelihood estimation (ALE) method was used to analyze eight studies in the orthographic task category, eleven in the phonological and fifteen in the semantic task categories. Converging activation among three language-processing components was found in the left middle frontal gyrus, the left superior parietal lobule and the left mid-fusiform gyrus, suggesting a common sub-network underlying the character recognition process regardless of the task nature. With increasing task demands, the left inferior parietal lobule and the right superior temporal gyrus were specialized for phonological processing, while the left middle temporal gyrus was involved in semantic processing. Functional dissociation was identified in the left inferior frontal gyrus, with the posterior dorsal part for phonological processing and the anterior ventral part for semantic processing. Moreover, bilateral involvement of the ventral occipito-temporal regions was found for both phonological and semantic processing. The results provide better understanding of the neural networks underlying Chinese orthographic, phonological, and semantic processing, and consolidate the findings of additional recruitment of the left middle frontal gyrus and the right fusiform gyrus for Chinese character processing as compared with the universal language network that has been based on alphabetic languages.     

母语为汉语者言语障碍的语义加工及其脑区机制

学术背景:语义的加工机制是认知神经科学关注的焦点问题之一,随着研究技术手段的不断创新和多样化,使得与语义加工的相关脑区及其各脑区的神经机制逐渐清晰。但是,目前有关汉语的语义加工机制的研究力度仍然不够,对于操汉语者所持有的汉语语义加工的脑神经机制的研究有待于进一步深化。目的:通过对操汉语者言语障碍的语义加工与相关脑区功能关系的研究成果的归纳,并对其相关的大脑神经机制与语义加工网络涉及的脑的局部系统及其功能与脑空间机构进行分析,进一步明确基础神经心理学对临床诊断、治疗及康复的意义。检索策略:作者对1984年至今的相关文献进行检索,关键词为"semantic processing",并限定文献语言为英文。检索的数据库主要有中国知网(CNKI)中国期刊全文数据库1994-01/2006-05、荷兰Elsevier公司期刊数据库1984-01/2006-05和美国EBSCOhost数据库1984-01/2006-05中Academic Source Premier和MEDLINE两个子数据库,同时手工检索与之内容相关的书籍。检索到文章264篇,纳入关于语义加工与脑区功能联系的43篇,并结合有关论著进行总结,排除联系不密切的文献,对于未发表的文章仅做参考使用。文献评价:文献来源于论著、汇总分析、个例报告、研究性报告。评价人为相关领域研究人员。资料综合:汉语语义加工的相关脑区主要涉及左侧颞上回、颞中回、颞叶前部、额下回以及左额叶中部,组成额-颞工作网共同支持语义加工,其中左侧颞上回后部和颞中回与语义加工关系最密切,涉及到语义的一般存储和自动加工,颞叶前部则与不同语义的整合加工有关;额下回与控制、执行加工,短时记忆加工有关联;左额叶中部是近年来发现的与汉语语义加工关系较大的脑区部位,现有的推论是汉字特有的字形结构的加工导致的。结论:目前,研究神经语言学的脑组织和机能的方法已经多样化,可以更逼真地观察和了解临床上的多种言语障碍及其病变机制,为言语障碍的临床治疗康复提供了极大的帮助。     

汉字词语语音、语义处理相关脑区的功能磁共振研究

目的探索汉字词语处理的脑偏侧化;研究汉字词语的语音、语义处理相关脑区及小脑在汉字词语处理中的作用.方法对13例健康、右利手、母语为汉语的受试者,采用功能磁共振成像技术,模块设计的刺激模式,运用视觉呈现方法,每名受试者参加两组实验:动词产生组及假词默读组.结果动词产生组及假词默读组均显著激活左侧额下回、左侧额中回、左侧额上回、左侧顶上小叶、双侧枕叶以及双侧小脑半球,在两组中均以左侧大脑半球激活为著;Wernicke区在两组均未见激活;左侧IFG在动词产生组较假词默读组激活范围广泛;双侧扣带回、左侧颞下回、右侧额中回、左侧丘脑及右侧尾状核仅在动词产生组被激活.结论左侧大脑半球是汉字词语处理的优势半球;Broca区在汉字词语处理中既有语音又有语义处理方面的作用;双侧小脑参与汉字词语的语音处理;大脑皮层下的一些核团可能参与汉字词语的语义处理.     

功能磁共振成像观察左颞前部在汉语听觉词加工中的机制

目的 探讨左侧颞前部在汉语听觉信息加工中的作用机制。方法 应用3.0T磁共振成像系统与标准头线圈对15名健康志愿者(男5名,女10名)进行功能磁共振成像(fMRI)。要求受试者完成听觉复述任务和听觉语义危险判断任务。应用软件包AFNI分析两种听觉任务在左颞前部的任务功能定位及其差异。结果 正常成人听觉语义判断任务相比听觉复述任务更多激活左侧颞中回及颞下回前部,而听觉语音复述任务相比听觉语义判断任务更多激活左侧颞上回前部。结论 脑内存在左颞前部对汉语听觉语音语义信息加工的分离,颞上前部对语音分析更强,颞前中下部对语义分析更强。     

From N400 to N300: variations in the timing of semantic processing with repetition

The present study aimed to explore the variations of semantic processing according to the number of target words (i.e., 4, 12 and 24) and according to the number of repetitions (i.e, 1 to 15). The number of targets had no impact on the N400 brain potential, the index of semantic processing, nor on the late positive component (LPC), an index of episodic encoding and retrieval. Analyses of the effects of the number of repetitions showed that the duration of semantic processes--assessed by measuring N400 latency--was linearly shortened along repetitions while their extent--as indexed by N400 amplitude--remained constant after the second presentation. In contrast, the extent of episodic processes--as indexed by LPC amplitude--was found to increase linearly with repetition. By showing that N400 latency may be much less stable than previously thought, these results bring new constraints on the functional correlates of this key stage in the processing of semantic information. They also suggest that semantic processes can be studied at high repetition rates whatever the number of target stimuli. Finally, our findings show that each episode of prior presentation has an impact on the late processing of a stimulus despite the absence of an explicit memory task.     

Interactions between endogenous and exogenous attention on cortical visual processing

Sensory processing is affected by both endogenous and exogenous mechanisms of attention, although how these mechanisms interact in the brain has remained unclear. In the present study, we recorded event-related potentials (ERPs) to investigate how multiple stages of information processing in the brain are affected when endogenous and exogenous mechanisms are concurrently engaged. We found that the earliest stage of cortical visual processing, the striate-cortex-generated C1, was immune to attentional modulation, even when endogenous and exogenous attention converged on a common location. The earliest stage of processing to be affected in this experiment was the late phase of the extrastriate-cortex-generated P1 component, which was dominated by exogenous attention. Processing at this stage was enhanced by exogenous attention, regardless of where endogenous attention had been oriented. Endogenous attention, however, dominated a later, higher-order stage of processing indexed by an enhancement of the P300 that was unaffected by exogenous attention. Critically, between these early and late stages, an interaction was found wherein endogenous and exogenous attention produced distinct, and overlapping, effects on information processing. At the same time that exogenous attention was producing an extended enhancement of the late-P1, endogenous attention was enhancing the occipital-parietal N1 component. These results provide neurophysiological support for theories suggesting that endogenous and exogenous mechanisms represent two attention systems that can affect information processing in the brain in distinct ways. Furthermore, these data provide new evidence regarding the precise stages of neural processing that are, and are not, affected when endogenous and exogenous attentions interact.     

Impaired semantic processing during sentence reading in children with dyslexia: combined fMRI and ERP evidence

Developmental dyslexia is a specific disorder of reading acquisition characterized by a phonological core deficit. Sentence reading is also impaired in dyslexic readers, but whether semantic processing deficits contribute is unclear. Combining spatially and temporally sensitive neuroimaging techniques to focus on semantic processing can provide a more comprehensive characterization of sentence reading in dyslexia. We recorded brain activity from 52 children (16 with dyslexia, 31 controls) with functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) in two separate counterbalanced sessions. The children silently read and occasionally judged simple sentences with semantically congruous or incongruous endings. fMRI and ERP activation during sentence reading and semantic processing was analyzed across all children and also by comparing children with dyslexia to controls. For sentence reading, we analyzed the response to all words in a sentence; for semantic processing, we contrasted responses to incongruous and congruous endings. Sentence reading was characterized by activation in a left-lateralized language network. Semantic processing was characterized by activation in left-hemispheric regions of the inferior frontal and superior temporal cortex and by an electrophysiological N400 effect after 240 ms with consistent left anterior source localization. Children with dyslexia showed decreased activation for sentence reading in inferior parietal and frontal regions, and for semantic processing in inferior parietal regions, and during the N400 effect. Together, this suggests that semantic impairment during sentence reading reduces dyslexic children's response in left anterior brain regions underlying the more phasic N400 effect and subsequently modulates the more sustained BOLD response in left inferior parietal regions.     

听觉呈现条件下汉语双字词语义和语音启动的事件相关电位研究

背景:在关于语义启动的事件相关电位研究中,N400(在刺激呈现后400ms左右出现的负波)成分占据重要的地位,被普遍认为反映了语义加工过程。不少研究证实,语义启动会导致N400波幅降低。而语音启动的研究较少,尤其是通过听觉呈现刺激的方式进行的的事件相关电位研究。目的:观察听觉呈现条件下汉语双字词的语音启动和语义启动事件相关电位特征,验证关于听觉词汇识别的相关理论。设计:重复测量实验。单位:天津师范大学心理与行为研究中心。对象:实验于2003-08/10在天津师范大学进行。选择17名天津师范大学在读大学生为被试,男生8名,女生9名,年龄19～23岁,身体健康,听力正常,母语为汉语,普通话标准。除1名男生外,其余均为右利手。所有受试大学生均对检测项目知情同意。方法:①本实验采用词汇决定任务,判断继时听觉呈现的词对中,后一个词为真词还是假词。要求被试进行按键反应。刺激材料为640对双字词组成的词对(包括词义相关、首音相同、尾音相同、音义无关及真假词对5类)。实验中5类词对以随机顺序呈现。②使用Stim呈现实验材料,该软件同时记录行为数据,对被试在4种实验条件下(词对间语义相关、首音相同、尾音相同、音义无关)的反应的错误率和平均反应时进行计算。对真假词对不进行分析(作为填充)。被试头戴美国Neuroscan公司Quick-Cap32导脑电帽(国际10-20系统),参考电极为双侧乳突连线,经Synamps放大器放大15000倍,采样频率500Hz,然后送入电脑由Scan4.3软件记录。对数据的离线分析包括利用SCAN软件中的OcularArtifactReduction功能去除连续文件中的眼电干扰、分段(分析时程从触发点前200ms至触发点之后1500ms)、基线矫正(-100～0ms为标准)、去伪迹(超过±100μV的数据作为伪迹排除)、叠加。主要观察指标:不同实验条件下目标词进行反应时的错误率、反应时间及引起的N400波形的变化。结果:17名被试的数据均被纳入结果分析。①语义相关条件下被试错误率低于音义无关(P<0.05),反应时短于音义无关(P<0.01);首音相同及尾音相同条件下被试错误率高于音义无关(P<0.01)。将错误的反应剔除,语义相关、首音相同、尾音相同和音义无关4种条件下的平均反应时分别为830,891,864和903ms。语义相关与音义无关相比差异显著(P<0.01);尾音相同与音义无关及首音相同差异明显(P<0.01)。②因为FCZ引发的N400最为显著,所以对4种实验条件下FCZ点引发的N400的波幅和潜伏期进行统计分析。LSD多重比较发现,音义无关波幅显著高于语义相关(P<0.01),音义无关峰潜时最长,其次分别为语义相关、尾音相同,时间最短的是首音相同。LSD多重比较显示,首音相同具有峰潜时缩短的趋势,与音义无关差异显著(P<0.05)。③考察不同实验条件下N400头皮分布的差异,除FCZ点之外,又选取了FZ、CZ、PZ、T7、T8分别作为前区、顶区、后区、左区和右区的代表点,对波幅进行4(实验条件)×2(电极位置)两因素重复测量方差分析。不同电极位置的主效应非常显著(P=0.000)。波幅最高的是FCZ(-7.946μV),其次分别为CZ(-7.285μV)、FZ(-6.849μV)、PZ(-4.324μV)、T8(-3.501μV)、T7(-3.484μV)。LSD多重比较表明,除CZ外,FCZ波幅高于其他代表点。结论:①在词汇决定实验中,通过听觉通道呈现汉语双字词,启动词与目标词之间存在语义联系可导致目标词的加工得到改善,表现为错误率降低、反应时缩短,以及N400波幅减小。②启动词与目标词之间的语音一致对目标词的加工既有干扰作用,又有促进作用。表现为错误率提高,但反应时趋向缩短,N400波幅亦呈下降趋势。③启动词与目标词首音相同比尾音相同有更大的干扰作用。这为交股理论所认为的在听觉词汇识别过程中首音具有特殊意义的看法提供了支持,不过该理论应用于汉语双字词识别需要进行一定的修正。④本实验没有发现语义启动语音启动具有不同脑内源的证据。