46例正常成人事件相关脑电位N400实验研究

目的 取得本实验室正常成人事件相关脑电位(ERP)N 400实验方法及正常值.方法 应用中国广州润杰WJ-1型ERP仪,对46名20～54岁右利手正常成人受试者,进行汉语成语正常结尾(匹配)与成语结尾歧义词(不匹配)的研究.结果 (1)分析了N 400基本波型,正常成人N 400波形较稳定.(2)建立了Cz、Fz和Pz区域N 400指标平均值.(3)波形分析所见,不匹配结尾词的N 400较匹配的N 400潜伏期较长,波幅高.N 400分布于Fz、Cz和Pz各区.结论 正常成人N 400是可靠的,可作为有临床价值的ERP用于精神科伴有语言障碍疾病的评估.     

正常成人汉语句子识别的事件相关脑电位N400实验研究

目的探讨正常成人汉语句子结尾词匹配和非匹配事件相关脑电位（ERP）N400的特点。方法应用ERP仪,对58名19～63岁正常成人右利手受试者,进行汉语正常句子结尾词（匹配）与句子结尾歧义词（非匹配）N400的实验研究。结果正常成人中央区（Cz）、前额区（Fz）及顶区（Pz）脑区汉语句子结尾词匹配的N400平均潜伏期为364ms,平均波幅为8.9μV;非匹配的N400的平均潜伏期为409ms,平均波幅为12.9μV。正常成人各脑区匹配与非匹配的汉语句子结尾词的N400潜伏期、波幅比较有统计学差异。结论正常成人汉语句子识别的N400稳定、可靠;非匹配的汉语句子结尾词的N400潜伏期长,波幅高。     

首发精神分裂症患者康复过程中事件相关脑电位N400随访

目的研究首发精神分裂症患者的N400变异与临床症状和康复的关系。方法对58例精神分裂症首发患者和62名健康成人作了N400检测。并用阳性和阴性症状量表(PANSS)评定患者精神症状。患者组于治疗6月、15月时进行N400随访。结果 (1)与健康成人相比,患者组服药前的N400潜伏期和波幅在Cz、Pz、Fz、C3、C45个脑区明显延迟于对照组和波幅下降。(2)N400潜伏期延迟和波幅下降与阳性症状分和PANSS总分呈负相关。(3)患者组在治疗后的6月、15月随访时,N400潜伏期和波幅有显著性差异(N400潜伏期,非匹配:治疗前446±35ms,治疗6月440±37ms,治疗15月414±31ms,F值=9.72,P<0.01。N400波幅,匹配:治疗前5.2±4.6μV,治疗6月5.7±4.8μV,治疗15月7.3±5.0μV,F值=2.06,P>0.05。非匹配:治疗前8.5±5.9μV,治疗6月10.1±5.0μV,治疗15月11.9±7.0μV,F值=3.697,P<0.05)。结论 N400对精神分裂症的疗效具有一定的预测作用。随访显示精神分裂症的语言及认识缺陷症状是渐进性过程,随着疗程或治疗发生相应变化。     

事件相关电位N400神经发生源研究

目的事件相关电位(event-related potentials,ERPs)N400是与语境歧义处理相关的高级认知电位,研究应用于精神分裂症的认知功能障碍。有关N400神经发生源,国内外均少有研究报道。本研究应用“低分辩率电磁断层扫描术(low resolution electromagnetic tomography,LORETA)”技术研究 N400的神经发生源。方法ERPs应用汉词语词对(S1-S2)诱发。S1-S2的关系为:语义关联对、语义非关联对和汉词-人造词对。脑电信号应用17导电极记录。被试为18例正常健康者,男9,女9,平均年龄25．2±4．4岁。应用LORETA软件中内含的“统计学非参数地形图(statistical non-parametric mapping,SnPM)”程序分析被试处理不同类语词时所激活的脑功能区差异。结果与语义关联词对中S2诱发ERPs相比,语义非关联词对中S2诱发出潜伏期在300-500 ms左右的负向偏转成分N400。分别比较S2开始后300-350 ms、350-400 ms、400-450 ms和450-500 ms时间窗内两类刺激语词激活的脑功能区,发现具有显著性差异的脑功能区集中在左半球的颞上回、颞中回、岛回、梭状回、后扣带回和海马旁回等区域。结论事件相关电位N400的神经发生源位于优势半球的颞叶及扣带回-海马结构。     

儿童抽动障碍事件相关电位N400的研究

目的探讨儿童抽动障碍患者事件相关电位N400的变化及其意义。方法用诱发电位检测仪测定35例抽动障碍患儿(病例组)的N400,并与20名正常儿童(正常对照组)进行比较。结果病例组N400的潜伏期为(706.87±198.99)ms,波幅为(26.12±13.64)μV,对照组为(485.75±85.76)ms和(22.35±19.76)μV。两组潜伏期比较,差异有非常显著性(P<0.001);波幅比较,差异无显著性(P>0.05)。结论抽动障碍患者的事件相关电位N400潜伏期明显延长,显示其存在认知功能障碍。     

精神分裂症患者脑源性神经营养因子与事件相关脑电位N400的相关性研究

目的:探讨精神分裂症患者脑源性神经营养因子(BDNF)与事件相关脑电位N400和临床症状之间的关系.方法:对58例精神分裂症患者(患者组)及60名健康对照(正常对照组)进行N400测查,采用酶联夹心免疫吸附法测定血清BDNF水平.使用阳性和阴性症状量表(PANSS)评定患者的临床症状.结果:患者组血清BDNF水平低于正...     

事件相关电位N400在脑卒中患者语言功能评估中的应用价值

目的探讨事件相关电位N400在脑卒中患者语言功能评估中的应用价值。方法对20例首发单病灶脑卒中患者(脑卒中组)和20名无脑损害的对照者(对照组)进行语言功能检查和N400检查,并对结果进行分析。结果脑卒中组书写障碍的发生率为35%,而对照组无书写障碍发生。脑卒中组口语表达、听理解、复述、命名、阅读各项得分均明显低于对照组(P<0.05~0.01)。脑卒中组选词填空得分[(83.0±24.32)分]明显低于对照组[(98.33±7.45)分](P<0.001)。脑卒中组N400各点潜伏期均较对照组明显延长,Pz、T4点波幅均较对照组明显降低(均P<0.05)。脑卒中组中,N400 T4点潜伏期较Fz点明显延长,波幅较Fz点明显降低(均P<0.05);T3、T4点波幅较Pz点明显降低(均P<0.05)。对照组中,N400各点潜伏期差异无统计学意义;Pz点波幅均显著高于Fz、T3、T4点(均P<0.05)。Spearman相关分析示,脑卒中患者句子-词语N400与阅读功能检查中选词填空项得分间无相关性。结论右颞可能参与语义的认知加工。N400与语言功能检查具有一致性,可以将N400运用于临床脑卒中患者语言功能的评估...     

门诊及长期住院的精神分裂症患者事件相关脑电位N400对照研究

目的:比较门诊及长期住院治疗的精神分裂症患者事件相关脑电位(ERPs) N400潜伏期及波幅。方法:采用汉语成语模式,对23例门诊精神分裂症患者(门诊患者组)、27例住院精神分裂症患者(住院患者组)进行N400检测,并与25名健康成人(正常对照组)比较。结果:与正常对照组比较,两患者组同音异形异义的匹配N400潜伏期显著延迟于对照组(P均0.01);住院患者组异音形似异义匹配、异音异形同义非匹配以及异音异形异义非匹配N400潜伏期显著延迟(P 0.05或P 0.01);两患者组异音异形同义的匹配、非匹配的N400波幅明显降低(P 0.05或P 0.01);住院患者组同音异形异义匹配、同音异形异义非匹配、异音形似异义匹配的N400波幅明显降低(P 0.05或P 0.01)。与门诊患者组相比,住院患者组异音异形同义非匹配以及异音异形异义非匹配N400潜伏期显著延迟明显延迟(P 0.05或P 0.01);异音异形同义非匹配N400波幅明显降低(P 0.01)。结论:精神分裂症患者存在特异性的语言障碍;长期住院患者语言障碍更明显。     

事件相关电位P300、N400在血管性痴呆疾病中的应用研究

目的研究血管性痴呆患者的事件相关电位P300、N400的临床应用.方法对40例血管性痴呆和34例正常对照组进行P300、N400测试.结果VD组N1、P2、N2和P3、N4潜伏期均明显延长,P2、N2、P3、N4波幅降低,与对照组比较,有显著性差异.结论事件相关电位P300、N400是一种客观的神经电生理指标.对VD的早期诊断有实用价值.     

青少年网络成瘾的事件相关电位N400研究

目的探讨网络成瘾青少年的事件相关电位N400变化及其与语言功能变化的关系。方法选取Young评分超过80分的网络聊天成瘾青少年20例,接受N400检测,刺激程序分为A和B两部分,A为不包含网络语言的语句(语义匹配和不匹配语句各40句),B为包含有网络语言的语句(其中网络语言40句,不包含网络语言的正常匹配句40句),语句刺激过程中同步采集脑电数据并离线进行N400分析;采用词语流畅性实验,了解语言认知功能损害程度。随即选取年龄,文化程度等背景相似的无网络成瘾的被试作为正常对照。结果网络成瘾组与对照组相比,N400检测显示潜伏期延长,波幅降低;带有网络语言成分句N400检测网络成瘾组未检测到明显N400波形成,而正常对照组检测发现有N400波;词语流畅性作业前者结果也少于对照组,两者之间存在显著差异。结论网络成瘾青少年出现常规语言流畅性功能下降,与N400变化具有一定相关性。     

Cognitive Event-Related Potentials in Comatose and Post-Comatose States

We review the interest of cognitive event-related potentials (ERPs) in comatose, vegetative, or minimally conscious patients. Auditory cognitive ERPs are useful to investigate residual cognitive functions, such as echoic memory (MMN), acoustical and semantic discrimination (P300), and incongruent language detection (N400). While early ERPs (such as the absence of cortical responses on somatosensory-evoked potentials) predict bad outcome, cognitive ERPs (MMN and P300) are indicative of recovery of consciousness. In coma-survivors, cognitive potentials are more frequently obtained when using stimuli that are more ecologic or have an emotional content (such as the patient’s own name) than when using classical sine tones.     

Abnormalities in Event-Related Potentials: N100, N200 and P300 Topography in Alcoholics

Abstract: Event-related potentials were recorded in 30 abstinent alcoholics, and 30 gender- and age-matched controls during a two-tone discrimination (odd ball) task. All the subjects were free from medication and dextral. The amplitudes of N100, N200 and P300 in the alcoholics were reduced and the P300 latency prolonged as compared with those of the controls. A P300 amplitude reduction occurred in the left and midline frontal, and the left and midline central regions. This is the first report of the amplitude of P300 being markedly decreased in the left hemispheres of the brains of the alcoholics. The results are discussed in terms of the cognitive dysfunctions of alcoholics.     

Native vs. second language discrimination in the modulation of the N400/N400m

The N400 evoked response component, initially proposed as a marker of semantic incongruity, was later demonstrated to be evoked by various potentially meaningful stimuli, such as words or pseudowords. The present study tested whether the N400 elicited by isolated words and pseudowords was modulated by task instructions thus reflecting controlled processing of linguistic information. In two language discrimination tasks, Finnish adults with English as their second language detected either Finnish or English nouns in a list of Finnish and English words and pseudowords. The same set of stimuli, presented in a random order, was used for both tasks. The amplitudes of both the evoked potentials and their magnetic counterparts were task‐language dependent. In both tasks, task‐language pseudowords elicited more negative evoked potentials (N400 and P600) than non‐task‐language pseudowords or words. The left temporal source of the evoked magnetic field was activated more strongly by English than Finnish pseudowords in the English task. This source was also activated more strongly by English pseudowords in the English task than in the Finnish task. However, no similar enhancement of the evoked magnetic field by Finnish pseudowords was observed in the Finnish task. This finding suggests that at the level of multimodal temporal cortex around the superior temporal sulcus, the native language is processed more automatically than the second language and that the controlled processing of linguistic information reflected by the N400 potential is accomplished by a broader neural network extending beyond the association temporal areas.     

汉字单字词识别的N400

目的　探讨单词识别过程中事件相关电位N40 0成分的心理学意义。方法　在长 ( 60 0ms)与短 ( 2 0 0ms)两种刺激呈现间隔 (SOA)、3种语境 (相关、中性和无关 )条件下 ,进行词汇抉择作业 ,通过对反应时间 (RT)和事件相关电位 (ERP)的检测 ,观察目标词词汇抉择的语义启动效应 (RT效应和N40 0波幅效应 )。结果　长SOA时 ,RT实验有语义促进效应 (相关语境RT较中性语境短 )和抑制效应 (无关语境RT较中性语境长 ) ,而ERP实验只有N40 0波幅抑制效应 ;短SOA时 ,RT实验只有语义促进效应 ,而ERP实验无任何N40 0波幅效应。结论　结果表明 ,N40 0反映了词汇后水平的整合加工 ,而不反映词汇水平的词汇提取加工。     

健康成人汉语成语尾字识别的N400研究

目的研究健康成人汉语成语尾字匹配与非匹配N400的变化。方法入选35名20～55岁健康成人右利手受试者,进行汉语成语匹配与非匹配N400的实验研究。结果 N400基本波型分布于Fz、Cz和Pz等脑区。分别获得健康成人同音异形异义、异音形似异义、异音异形同义及异音异形异义汉语成语尾字匹配与非匹配的N400潜伏期和波幅平均值。结论汉语成语尾字匹配和非匹配N400的改变与字词认知中的语义有关。     

The N400 as an index of racial stereotype accessibility

The current research examined the viability of the N400, an event-related potential (ERP) related to the detection of semantic incongruity, as an index of both stereotype accessibility and interracial prejudice. Participants’ EEG was recorded while they completed a sequential priming task, in which negative or positive, stereotypically black (African American) or white (Caucasian American) traits followed the presentation of either a black or white face acting as a prime. ERP examination focused on the N400, but additionally examined N100 and P200 reactivity. Replicating and extending previous N400 stereotype research, results indicated that the N400 can indeed function as an index of stereotype accessibility in an interracial domain, as greater N400 reactivity was elicited by trials in which the face prime was incongruent with the target trait than when primes and traits matched. Furthermore, N400 activity was moderated by participants’ self-reported explicit bias. More explicitly biased participants demonstrated greater N400 reactivity to stereotypically white traits following black faces than black traits following black faces. P200 activity was additionally associated with participants’ implicit biases, as more implicitly biased participants similarly demonstrated greater P200 reactivity to stereotypically white traits following black faces than black traits following black faces.