视觉事件相关电位

一、概况 事件相关电位(event-related potential,ERP)1965年由Sutton提出。一般认为有广义和狭义之说,广义指ERP的全部成分,包括P1、N1、P2、N2、P3,MMN、N400、CNV,而狭义仅指P1、N1、P2、N2、N3。关于刺激模式,国内外大多采用听觉刺激。目前国内使用的仪器     

38例正常人事件相关电位分布研究

本文报告38名正常人听觉性ERP的部位效应研究结果。反映认知心理加工过程的ERP中的P_3波的电位分布:Cz点波幅最大,波型最佳,易识别和测量,其后依次为Fz、Pz,C_3或C_4和Oz各点。P_3波的潜时:Pz点最短,Fz点最长,依次为Cz、C3或C_4和Oz,各记录间无统计学意义.而Fp_1、Fp_2,T_3·T_4,P_3·P_4,C_3·C_4.O_1·O_2各点记录的ERP均不如沿中线各点记录的清楚。     

正常人听觉事件相关电位中P_(300)与智商关系的研究

目的 :探讨正常人听觉P30 0 与智商之关系 ,评价P30 0 在智力测验中的应用价值。方法 :对 38例病人采用oddball刺激序列检测P30 0 ,采用中国修订韦氏成人智力量表全量表测定智商。结果 :全组 38例 ,P30 0 潜伏期为 35 7 9± 2 6 4ms ,波幅 12 5± 5 9μⅴ ;智商测定言语智商 113 7± 13 2分 ,操作智商10 8 7± 11 3分 ,总智商 111 9± 12 5分。相关分析显示P30 0 潜伏期与各智商间均呈显著负相关 (r =-0 2 73～ - 0 32 9,P <0 .0 5 ) ,波幅与言语智商及总智商呈显著正相关 (P <0 .0 5 )。结论 :P30 0 潜伏期在表达智商方面具有显著意义。     

视觉事件相关电位（P300）地形图及其应用

一、概念视觉事件相关电位（P300）地形图是一种人们对某种刺激（视觉）事件进行信息加工时,有心理或语言等因素参与的诱发电位地形图,是观察人脑信息加工过程的电位活动的重要手段。它又称为视觉认知电位（cognitive potential）地形图,或称为视觉后发性正相成分（late positive component,LPC）地形图,有的称为视觉联系皮层电位地形图。二、基本方法和原理先做出视觉事件相关电位P300曲线图,然后经过FFT转换为地形图。     

人脑对视觉信息变化的处理过程的事件相关电位研究

目的:采用256导联事件相关电位技术和低分辨率电磁图的方法,研究人脑对视觉信息变化的处理过程.方法:12名健康志愿者参与试验.视觉刺激为同时具有颜色和形状2种特征的图形.先后呈现的2张图片(S1和S2)组成一个刺激对并分为4种类型:S1和S2的颜色、形状均相同;S1和S2的颜色相同,形状不同;S1和S2的颜色不同,形状相同;S1和S2的颜色、形状均不同.受试者分别完成注意颜色和注意形状2个任务.结果:①S2呈现后135 ms～165 ms,3种变化的刺激对引出了变化相关正波(change-related positivity,CRP).低分辨率电磁图(low-resolution electromagnetic tomography,LORETA)分析显示CRP的发生源是枕叶舌回、楔叶.②235 ms～275 ms时间窗内,无变化和无关变化状态引出了N200,右侧颞叶梭状回、颞中回和海马旁回是该成分的发生源.③240 ms～320 ms时间窗内,所有变化的刺激对均引出了N270,前扣带回和双侧杏仁核是N270的发生源.结论:人脑对视觉信息变化的处理过程可分为3个阶段:CRP所代表的可能是人脑对视觉信息变化的早期处理阶段;N200所反映的可能是人脑对无关信息变化的主动忽略阶段;N270可能代表高级处理阶段.     

神经衰弱患者事件相关电位研究

本文对神经衰弱患者及正常对照者进行了事件相关电位检查,分析其中P_(300)成分的潜伏期、波幅,结果发现与正常对照组相比,神经衰弱患者P_(300)波幅较低,而潜伏期无显著差异,表明患者大脑皮质功能弱化。本研究结果提示事件相关电位可作为诊断神经衰弱的一项辅助检查。     

帕金森病事件相关电位的研究

帕金森病是一常见的锥体外系疾病 ,并存在认知功能障。本文对 5 6例帕金森病进行事件相关电位 (ＥＲＰ)研究 ,以客观地评定患者的认知功能。现报告如下。1　 对象和方法1 1　 检测对象病例组 :为 1997年 5月— 2 0 0 0年 1月我院门诊及住院病人 ,依据 1984年全国锥体外系疾病讨论会制定的诊断标准[1] 明确诊断。 5 6例中 ,男 34例 ,女 2 2例 ,年龄 39～ 79岁 ,平均 6 0 5岁 ,均为右利手。对照组 :为同期门诊健康体检者。共 5 0例 ,男 31例 ,女19例。年龄 38～ 81岁 ,平均年龄 6 1岁。均为右利手。各年龄段、性别、受教育程度两组相匹配。1 …     

正常人事件相关电位的检测与分析

本文报道ERP的检测方法和240例正常人的检测结果。探讨P_?波正常值范围及影响因索。结果表明.P_?波潜伏期为343.64±25.47ms,波幅P_?——N_?为7.15±3.90ηV,N_?——P_?为13.13±5.41μ。潜伏期、波幅与性别之间无显著性差异。但随着年龄的增加,潜伏期延长和波幅下降。     

单次事件相关电位聚类分析

本文用模糊神经网络对意境欠事件相关电位进行聚类分析，并提出应用奇异值分解确定最佳聚类数的通用新方法，结果显示它们构成了提取和压缩ＳＥＲＰ动态信息的有效方法 。     

正常青年人视觉、听觉诱发的ERP的比较

对３５例正常青年人同时进行视觉、听觉不同刺激模式检测到的事件相关电位（ＥＲＰ）进行比较分析，发现不同刺激模式诱发出的ＥＲＰ各波的潜伏期、波幅均不相同。本文对其原因和不同年龄的Ｐ３波在颅顶有不同的分布部位以及其中一些Ｐ３波电位值两半球不对称性的机理进行了初步探讨。     

Influence of task difficulty on the features of event-related potential during visual oddball task

We present a comprehensive analysis of the change in event-related potential (ERP) due to task difficulty during a visual oddball task. Specifically, we investigated the inter-subject difference in difficulty-related change of ERP patterns using single-trial ERP analysis focusing on P300 and P2 components. ERPs were recorded and analyzed from 14 subjects while performing a visual oddball task with two difficulty levels. After extracting independent components (ICs) from single-trial ERPs, the averaged ERPs were used to identify which ICs originated from major ERP components. The ERP components were estimated from single-trial waveforms by back-projecting relevant ICs onto scalp electrodes after removing all other ICs; thus, the comparison of ERP components could be performed for each subject. The averaged P300 amplitude was smaller and latency was larger for the more difficult task, and this tendency was also observed for single-trial ERP analysis within each subject. P2 amplitude increased for the hard task for both group and individual analyses, suggesting that the P2 may be interpreted as a manifestation of task relevance evaluation or response generation. The P2 amplitude and latency were more notably correlated with response time for the more difficult task.     

Comparison of spatiotemporal cortical activation pattern during visual perception of Korean, English, Chinese words: an event-related potential study

The aim of this study was to compare spatiotemporal cortical activation patterns during the visual perception of Korean, English, and Chinese words. The comparison of these three languages offers an opportunity to study the effect of written forms on cortical processing of visually presented words, because of partial similarity/difference among words of these languages, and the familiarity of native Koreans with these three languages at the word level. Single-character words and pictograms were excluded from the stimuli in order to activate neuronal circuitries that are involved only in word perception. Since a variety of cerebral processes are sequentially evoked during visual word perception, a high-temporal resolution is required and thus we utilized event-related potential (ERP) obtained from high-density electroencephalograms. The differences and similarities observed from statistical analyses of ERP amplitudes, the correlation between ERP amplitudes and response times, and the patterns of current source density, appear to be in line with demands of visual and semantic analysis resulting from the characteristics of each language, and the expected task difficulties for native Korean subjects.     

An event-related brain potential study of visual selective attention to conjunctions of color and shape

What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other conjunctions of these attributes in three discriminability conditions. Attending to color and shape produced three ERP effects: frontal selection positivity (FSP), central negativity (N2b), and posterior selection negativity (SN). The results suggested that the processes underlying SN and N2b perform independent within-dimension selections, whereas the process underlying the FSP performs hierarchical between-dimension selections. At posterior electrodes, manipulation of discriminability changed the ERPs to the relevant but not to the irrelevant stimuli, suggesting that the SN does not concern the selection process itself but rather a cognitive process initiated after selection is finished. Other findings suggested that selection of multiple visual attributes occurs in parallel.     

Grammatical number agreement processing using the visual half-field paradigm: An event-related brain potential study

Despite indications in the split-brain and lesion literatures that the right hemisphere is capable of some syntactic analysis, few studies have investigated right hemisphere contributions to syntactic processing in people with intact brains. Here we used the visual half-field paradigm in healthy adults to examine each hemisphere's processing of correct and incorrect grammatical number agreement marked either lexically, e.g., antecedent/reflexive pronoun (“The grateful niece asked herself/*themselves…”) or morphologically, e.g., subject/verb (“Industrial scientists develop/*develops…”). For reflexives, response times and accuracy of grammaticality decisions suggested similar processing regardless of visual field of presentation. In the subject/verb condition, we observed similar response times and accuracies for central and right visual field (RVF) presentations. For left visual field (LVF) presentation, response times were longer and accuracy rates were reduced relative to RVF presentation. An event-related brain potential (ERP) study using the same materials revealed similar ERP responses to the reflexive pronouns in the two visual fields, but very different ERP effects to the subject/verb violations. For lexically marked violations on reflexives, P600 was elicited by stimuli in both the LVF and RVF; for morphologically marked violations on verbs, P600 was elicited only by RVF stimuli. These data suggest that both hemispheres can process lexically marked pronoun agreement violations, and do so in a similar fashion. Morphologically marked subject/verb agreement errors, however, showed a distinct LH advantage.     

被试者心理因素对事件相关电位测谎准确性的影响

事件相关电位用于测谎是近几年才新发展起来的测谎方法。本实验以熟悉和陌生人照片视觉事件相关电位进行测谎研究，通过控制被试者实验时心理条件观察注意，有无任务对测谎准确性的影响。结果说明以人物照片为刺激，利用Ｐ３进行测谎是可行的，但被测者心理因素会影响其准确性，分散注意力时阳性率下降。     

The preattentive processing of major vs. minor chords in the human brain: An event-related potential study

Western music has two classifications that are highly familiar to all Western listeners: the dichotomy between the major and minor modalities and consonance vs. dissonance. We aimed at determining whether these classifications already take place at the level of the elicitation of the change-related mismatch negativity (MMN) component of the event-related potential (ERP). To this end, we constructed an oddball-paradigm with root minor, dissonant and inverted major chords in a context of root major chords. These stimuli were composed so that the standard and deviant chords did not include a physically deviant frequency which could cause the MMN. The standard chords were transposed into 12 different keys (=pitch levels) and delivered to the participants while they were watching a silent movie (ignore condition) or detecting softer target sounds (detection condition). In the ignore condition, the MMN was significant for all but inverted major chords. In the detection condition, the MMN was significant for dissonant chords and soft target chords. Our results indicate that the processes underlying MMN are able to make discriminations which are qualitative by nature. Whether the classifications between major and minor modalities and consonance vs. dissonance are innate or based on implicit learning remains a question for the future.     

Auditory and visual semantic priming using different stimulus onset asynchronies: An event-related brain potential study

Semantic priming effects (behavioral and electrophysiological) were compared in the visual and auditory modalities across three stimulus onset asynchronies (SOAs; 0, 200, and 800 ms). When both prime and target were presented in the visual modality (the prime just to the left of a fixation point and the target to the right) there were N400 priming effects present across the three SOAs. However, the N400 in the 0-ms SOA condition extended longer in time (800 vs. 500 ms) than in the other SOAs. When both the prime and target were presented in the auditory modality (the prime to the right ear and the target to the left), the largest priming effects were found for the 800-ms SOA. Moreover, there was a relatively early priming effect present in the 0- and 800-ms SOA conditions but not in the 200-ms condition. The results are discussed in terms of modality differences in the time course of word comprehension processes.     

作业记忆负荷及年龄对ERP的影响

本研究采用了３种不同记忆负荷视觉信息选择的作业，对４个年龄组（９．８±０．７、１２．０±０．７、１４．１±０．８和１７．１±０．８），共２５９名正常青少年各作业时的工效，以及事件相关电位（ＥＲＰ）进行了分析。结果表明，在相同记忆负荷条件下，随年龄增长工效显著提高；反应时（ＲＴ）和ＥＲＰ的Ｐ_（３００）潜伏期（ＰＬ）明显缩短。在年龄相同情况下，随记忆负荷加大，工效显著下降；ＲＴ和ＥＲＰ的Ｐ_（３００）ＰＬ明显延长。ＲＴ和Ｐ_（３００）的ＰＬ与年龄呈负相关（ｒ＝－０．６）；与作业负荷呈正相关（ｒ＝０．９）。信息处理工效与ＥＲＰ综合分析，能有效地评价脑功能，适用于临床及工效学研究。