大脑中汉语"介词"加工的依赖性机制:来自事件相关电位研究的证据

目的考察分析汉语中动词与介词在大脑神经加工机制上的异同。方法采用事件相关电位（event—relatedpotentials,ERP）技术,选择以汉语为母语的正常被试者共16人,观察被试者在加工两类词时脑电的ERP波形变化。结果动词与介词的原始波比较结果表明,动词与介词在230—330ms的时间窗口均诱发一个负波,在350-500ms也均诱发一个负波,它们在峰值上均无显著差异;动词与介词的差异波比较结果表明,无论是在语义上还是句法上,发现两个类型的单词在刺激呈现后270—400ms和470—600ms的时间窗口内,在大脑两侧均诱发一个负波。结论大脑对动词与介词的加工机制没有出现显著差异,介词难以独立成类,N280也非虚词的特定性成分。     

心跳感知对心跳诱发脑电位的影响

目的 早期研究发现心跳感知能力不同的人其心跳诱发脑电位(heartbeat evoked potential,HEP)存在差异.本文设计两个实验以对比研究在关注状态和静息状态下,心跳感知能力强和心跳感知能力弱的人HEP的具体差异.方法 采集22名被试者的30通道的脑电波,通过精神跟踪方法将被试者分为心跳感知能力强和感知能力弱两组.使用主成分分析方法去除掺杂在HEP中的心电场伪迹.结果 (1)对于心跳感知能力强的被试者,关注状态和静息状态的HEP存在着差异.差异主要体现在C3处心电R波后250-450 ms和C4处心电R波后100-300 ms.(2)感知能力强和感知能力弱的被试者的HEP差异波主要体现为FZ处心电R波后220-340 ms的一个正波;在关注状态下,这种差异更明显.结论 关注因素可能更容易影响心跳感知能力强的被试者;在关注状态,感知能力对HEP的影响更为明显.     

心跳感知对心跳诱发脑电位的影响

目的早期研究发现心跳感知能力不同的人其心跳诱发脑电位(heartbeat evoked potential,HEP)存在差异。本文设计两个实验以对比研究在关注状态和静息状态下,心跳感知能力强和心跳感知能力弱的人HEP的具体差异。方法采集22名被试者的30通道的脑电波,通过精神跟踪方法将被试者分为心跳感知能力强和感知能力弱两组。使用主成分分析方法去除掺杂在HEP中的心电场伪迹。结果(1)对于心跳感知能力强的被试者,关注状态和静息状态的HEP存在着差异。差异主要体现在C3处心电R波后250-450ms和C4处心电R波后100- 300ms。(2)感知能力强和感知能力弱的被试者的HEP差异波主要体现为FZ处心电R波后220-340 ms的一个正波;在关注状态下,这种差异更明显。结论关注因素可能更容易影响心跳感知能力强的被试者;在关注状态,感知能力对HEP的影响更为明显。     

情绪词汇加工的事件相关电位的时空模式研究

目的 通过事件相关电位(ERP)的时空模式探讨不同知觉条件下情绪词汇加工的神经机制.方法 11名受试者从事情绪词汇加工后呈现的面孔照片组合的面孔性别判别任务.对不同知觉条件下情绪词与中性词的ERP差异波采用2(知觉:非觉察、觉察)×2(情绪词:正/中性、负/中性)重复测量方差分析,利用F值的统计参数映像呈现结果 .结果 F值统计参数映像显示:(1)显著交互效应(知觉×情绪)主要出现在左侧额颞区及右侧枕区(60～80ms);(2)显著知觉效应主要出现在双侧额区和右颞区(110～150 ms);(3)显著情绪效应主要出现在左右半球的广泛区域(60～90ms).结论 ERP的时空模式提示了非觉察和觉察条件下情绪词汇加工早期激活同一神经网络,前者的激活强度较后者弱.     

反射性注意线索范式下眼球指向加工引起事件相关电位成分及时序性变化

摘要： 背景：眼球指向可以引起相关大脑区域的激活,这种激活在一定程度上具有特异性、视野优势和时间进程上的差异。 目的：探讨眼球指向的有效性对视觉反射性注意的脑电活动规律的影响。 设计、时间及地点：被试内实验设计,于2009-07/20~2009-08/01在北京师范大学心理学院脑电实验室完成。 对象：被试采取自愿报名的方式,按纳入和排除标准,共募集14名年龄为18~23岁（Mean age=21）的健康的北京师范大学本科生,男7人,女7人。纳入标准：选取视力或者矫正视力正常（裸眼或矫正视力国标1.0以上）的本科生,被试在实验过程中无显著的脑电漂移。排除标准：视觉和矫正视觉异常的被试,被试在实验过程中出现显著的脑电漂移。 方法：采用事件相关电位的脑电记录方法对14名大学生进行眼球指向的视觉注意加工实验。根据其脑电图记录的分析结果,找出视野和眼球指向有效性引起的注意加工的大脑神经细胞脑电活动差异,并探讨在时间进程上诱发的脑电成分的活动规律。 主要观察指标：用事件时间相关电位的方法记录分布在大脑的各功能区电极在时间进程上（0~800ms）的诱发电位,来观察左右视野、眼球朝向有效性的视觉注意加工规律。 结果：左右视野和眼球朝向引起早期波N1、P1、P2的峰值和潜伏期,眼球朝向有效性诱发了早期波和晚期波电极点（P7、P8、F7、F8、PO3、PO4）的半球优势,且差异有统计学意义（P<0.05）。结果发现在眼球指向的注意线索任务中,发现了早期反射性注意的EDAN和ADAN,没有发现晚期的LDAP成分。 结论：眼球指向的反射性注意转移存在半球优势;且诱发了早期的EDAN（200~400 ms）和ADAN(400-500ms)脑电成分,没有引起晚期的LDAP(500~800ms)成分。这说明视觉反射性注意发生在视觉刺激呈现的很短时间内,存在明显的注意加工优势。 关键词：眼球朝向;提示有效性;事件相关电位;半球优势;反射性注意     

老年人和青年人注意网络的研究

目的探讨老年化对警觉、定向和执行控制等x注意网络加工的影响。方法运用注意网络测试(ANT)观察30名老年人和30名青年人正常被试的警觉、定向和执行控制等注意网络功能。结果与青年人被试者(执行网络为66.8±32.3ms;警觉网络为55.9±31.2ms;定向网络为46.1±20.6ms)相比,老年人被试者注意的执行控制网络功能效应时间明显延长(124.3±64.9ms,P<0.01)以及警觉网络功能效应时间明显缩短(31.7±36.6ms,P<0.05),显著受损;而定向网络功能无差异。结论脑的老年化改变显著影响注意网络的认知加工,老年化对注意的执行控制和警觉网络的影响,可能与年龄相关的额叶功能退化和神经递质系统的异常有关。     

5000/线索位置对复合字母加工影响的ERP研究

研究者在前置线索范式中对复合字母加工进行了广泛研究,本研究同时记录和分析前置线索与后置线索两种条件下对复合字母加工规律的ERP（Event-Related Potentials）信号。研究结果显示,前置线索与后置线索下被试显示出不同的加工模式。前置线索条件下,对复合字母的加工引起大脑前部早期波N1和晚期波P3的半球不对称;对整体反应和局部反应在早期波和晚期波均表现出差异,且大小字母一致性在加工晚期的P3上表现出差异。而在线索后置时,没有显示出脑电波的左右半球不对称性;且对整体反应和局部反应没有差异;大小字母一致和不一致时,早期波N1、P1在前部脑区与后部脑区均差异显著,表明加工早期阶段,对整体的加工与对局部的加工之间存在严重的相互干扰。后置线索条件下,大小字母一致不一致引起左半球加工的差异,对不一致的字母加工有更大波幅,且右半球没有这种差异。     

正常青年人对图像、照片和汉字刺激诱发P300波的比较

目的比较正常青年人对图像、照片和汉字3种不同刺激所诱发P300波的潜伏期(PL)和波幅(Amp)的差异.方法分别记录和比较32名正常青年人对图像、照片和汉字3种不同刺激诱发P300PL和Amp.结果汉字诱发P300PL与其他两种刺激诱发P300PL之间差异有极显著性(P<0.01),而3类刺激诱发P300Amp不存在差异.性别之间除照片刺激诱发P300PL无差异外,其他指标均存在差异(均P<0.05).结论不同视觉刺激诱发P300PL之间的差异可能与大脑对其分析、加工、整合所需的时间有关.与受试者的性别也有一定关系.     

抑郁症患者汉语情绪词阈下的Stroop效应事件相关电位

背景：抑郁症患者负性认知偏差与情绪信息加工的关系是一个重要的研究课题。情绪Stroop测验常用于评估情绪加工特点,而情绪词阈下Stroop刺激模式也常用于精神病学临床研究。 目的：本研究采用阈下汉语情绪词Stroop刺激范式来探讨抑郁症患者异常情绪信息加工的事件相关电位(ERP)效应。 设计,时间和地点：随机对照设计,时间为2007年8月至2008年3月,地点在中南大学湘雅二医院。 研究对象：首发抑郁症患者26例,符合DSM-IV抑郁症诊断标准,无脑部疾病、躯体疾病,未进行电休克治疗和抗抑郁药物治疗。健康对照组24例。两组在年龄、性别和教育水平方面无差异,均为右利手。 方法：采用阈下汉语情绪词Stroop刺激范式,要求被试对呈现200ms的红色或蓝色方块进行反应,而汉语情绪词阈下启动刺激为20ms。主要分析行为学和ERP数据。 主要测试指标：反应时和ERP成分的潜伏期和波幅。参照ERP平均波幅图以及其它研究,主要分析N270 (220~300ms)成分和N400 (380~450ms)成分的潜伏期和波幅。 结果：行为数据显示两组正确率之间无显著性差异,抑郁症组反应时比正常对照组延长,尤其是负性词与中性词(p<0.01)。重复测量方差分析表明,N270成分的波幅有词性和电极的主效应(p<0.01)以及词性和电极的交互效应(p<0.05);两组波幅大小顺序均为正性词>负性词>中性词。组别、词性差异波地形图显示差异主要分布在额区和左侧顶颞区。N400成分的波幅有词性和电极的主效应(p<0.01),潜伏期显示电极的主效应(p<0.01)以及电极和组别的交互效应(p<0.01);两组波幅大小顺序均为正性词>负性词>中性词,而且两组之间的三种情绪词波幅之间有显著性差异(p<0.01)。组别、词性差异波地形图显示差异主要分布在左右额区、中央区和左侧顶颞区。 结论：抑郁症患者执行阈下汉语情绪词Stroop刺激作业时表现了异常的情绪信息加工特征,以及对汉语情绪词三种词性进行语义激活时与正常组相比表现为不同的ERP时程效应。研究结果支持我们提出的正负性情绪平行神经模型。     

强制和自愿戒毒者线索诱发海洛因渴求反应的差异

目的 比较环境线索诱发强制和自愿戒毒者海洛因渴求反应的差异。方法 208名强制戒毒被试者和172名自愿戒毒被试者暴露于海洛因相关环境线索,根据被试者的自我报告,采用Likert分级法评价线索诱发的渴求程度,填写主观戒断反应问卷、毒品使用情况和一般社会学资料,并测量暴露前后血压、心率及瞳孔。采用独立样本t检验,比较线索暴露诱发强制和自愿戒毒被试者渴求及生理指标的差异。结果 暴露后,自愿戒毒被试者的渴求分值明显高于强制戒毒被试者（P〈0．01）,强制戒毒被试者暴露前的收缩压和舒张压均明显高于自愿戒毒被试者（P〈0．01）,但暴露后两组血压未见显著性差异（P〉0．05）。结论 环境线索诱发强制和自愿戒毒被试者渴求反应存在差异,可能与实验地点、调查者和测量方法的不同有关。     

An event-related potential observation of preposition processing in Chinese**★ Is N280 a specific component for Chinese prepositions?

BACKGROUND: Studies have shown that closed-class words, such as prepositions and conjunctions, induce a left anterior negativity (N280), indicating that N280 should be a specific component of the word category. OBJECTIVE: To observe if Chinese prepositions and verbs exhibit different linguistic functions, to determine whether they are processed by different neural systems, and to verify that N280 is a specific component. DESIGN, TIME AND SETTING: The observed neurolinguistics experiment was performed at Xuzhou Normal University between November and December 2006. PARTICIPANTS: Sixteen undergraduate students, comprising 8 females and 8 males, with no mental or neuropathological history, were selected. METHODS: A total of 15 verbs and prepositions were used as linguistic stimuli, and each verb and preposition was combined to produce four correct phrase collocations and four incorrect ones. MAIN OUTCOME MEASURES: Event-related potentials were recorded in the subjects while they read correct or incorrect phases flashed upon a video screen. RESULTS: Both verbs and prepositions elicited negativity at the frontal site in a 230–330 ms window, as well as at the fronto-temporal and central sites in a 350–500 ms window. Neither exhibited significant differences in peak [F (1, 15) = 0.144, P = 0.710] and latency [F (1, 15) = 0.144, P = 0.710]. Both verbs and prepositions elicited negativity at the left and right hemisphere in a 270–400 ms window. CONCLUSION: There was no significant difference between Chinese prepositions and verbs in the neural system process and N280 was not the specific component for closed-class words. Key Words: Chinese words; event-related potentials; prepositions; semantics; syntax; verbs     

Electrophysiological signatures of visual lexical processing: open- and closed-class words.

This paper presents evidence of the disputed existence of an electrophysiological marker for the lexical-categorical distinction between open- and closed-class words. Event-related brain potentials were recorded from the scalp while subjects read a story. Separate waveforms were computed for open- and closed-class words. Two aspects of the waveforms could be reliably related to vocabulary class. The first was an early negativity in the 230- to 350-msec epoch, with a bilateral anterior predominance. This negativity was elicited by open- and closed-class words alike, was not affected by word frequency or word length, and had an earlier peak latency for closed-class words. The second was a frontal slow negative shift in the 350- to 500-msec epoch, largest over the left side of the scalp. This late negativity was only elicited by closed-class words. Although the early negativity cannot serve as a qualitative marker of the open- and closed-class distinction, it does reflect the earliest electrophysiological manifestation of the availability of categorical information from the mental lexicon. These results suggest that the brain honors the distinction between open- and closed-class words, in relation to the different roles that they play in on-line sentence processing.     

Lexical processing of vocabulary class in patients with Broca's aphasia: an event-related brain potential study on agrammatic comprehension

This paper presents electrophysiological evidence of an impairment in the on-line processing of word class information in patients with Broca's aphasia with agrammatic comprehension. Event-related brain potentials (ERPs) were recorded from the scalp while Broca patients and non-aphasic control subjects read open- and closed-class words that appeared one at a time on a PC screen. Separate waveforms were computed for open- and closed-class words. The non-aphasic control subjects showed a modulation of an early left anterior negativity in the 210-325ms as a function of vocabulary class (VC), and a late left anterior negative shift to closed-class words in the 400-700ms epoch. An N400 effect was present in both control subjects and Broca patients. We have taken the early electrophysiological differences to reflect the first availability of word-category information from the mental lexicon. The late differences can be related to post-lexical processing. In contrast to the control subjects, the Broca patients showed no early VC effect and no late anterior shift to closed-class words. The results support the view that an incomplete and/or delayed availability of word-class information might be an important factor in Broca's agrammatic comprehension.     

Differences in brain potentials to open and closed class words: class and frequency effects

Closed class (determiners, pronouns, conjunctions, prepositions etc. ) and open class (nouns, verbs, adjectives, adverbs) words have different linguistic functions and have been proposed to be processed by different neural systems. Here, event-related potentials (ERPs) were recorded in young German-speaking subjects while they read closed class and open class words flashed upon a video-screen. In the first experiment closed class words were sorted into four different frequency categories and open class words into three categories. The words were presented in a list with the subjects' task to detect occasional non-words. A centroparietal negativity (N400) with a peak latency of about 400 ms varied in amplitude as a function of frequency in both classes. The N400 in closed class items, however, was considerably smaller than that in open class words of similar frequency. A left anterior negativity (N280/LPN) showed some degree of frequency-sensitivity regardless of word class. Only for the very high frequency closed class words a frontal negativity with an onset of about 400 ms was obtained (N400-700). This N400-700 effect was replicated in the second study, in which medium frequency closed and open class words and very high frequency closed class words were presented at the fifth position of simple German sentences. It is suggested that neither N400 nor the left anterior negativity (N280/LPN) distinguish qualitatively between the two word classes and thus claims about different brain systems involved in the processing of open and closed class words are not substantiated electrophysiologically. The N400-700 effect is possibly related to specific grammatical functions of some closed class items, such as determiners.     

Cortical potentials related to decision-making: comparison of two types of go/no-go decision

The S1-S2 go/no-go reaction time task has been frequently used to assess volitional inhibition. In this study our aim was to compare the ERPs elicited by S1 and S2 by using a modified S1-S2 paradigm which involved a two-stage go/no-go decision. The go and the no-go S1 ERPs did not differ substantially, and both displayed a prominent negativity with peaks at 260 ms (S1N260) and at 330 ms (S1N330) post-S1. The S1N260 was similar to the N2 from no-go S2 trials. Since after all three types of stimuli, movement is not required and is inappropriate, this negativity may represent the correlate of the voluntary decision to suppress movement. Later, the S1 ERPs were dominated by frontal negativity (S1N330), probably reflecting further processes related to response preparation, while the S2 ERPs displayed a large central and parietal positivity (P3), probably reflecting the processes of evaluation of response accuracy.     

The neural basis of analogical reasoning: an event-related potential study

The spatiotemporal analysis of brain activation during the execution of easy analogy (EA) and difficult analogy (DA) tasks was investigated using high-density event-related brain potentials (ERPs). Results showed that reasoning tasks (schema induction) elicited a more negative ERP deflection (N500-1000) than did the baseline task (BS) between 500 and 1000 ms. Dipole source analysis of difference waves (EA-BS and DA-BS) indicated that the negative components were both localized near the left thalamus, possibly associated with the retrieval of alphabetical information. Furthermore, DA elicited a more positive ERP component (P600-1000) than did EA in the same time window. Two generators of P600-1000 were located in the medial prefrontal cortex (BA10) and the left frontal cortex (BA6) which was possibly involved in integrating information in schema abstraction. In the stage of analogy mapping, a greater negativity (N400-600) in the reasoning tasks as compared to BS was found over fronto-central scalp regions. A generator of this effect was located in the left fusiform gyrus and was possibly related to associative memory and activation of schema. Then, a greater negativity in the reasoning tasks, in comparison to BS task, developed between 900-1200 ms (LNC1) and 2000-2500 ms (LNC2). Dipole source analysis (EA-BS) localized the generator of LNC1 in the left prefrontal cortex (BA 10) which was possibly related to mapping the schema to the target problem, and the generator of LNC2 in the left prefrontal cortex (BA 9) which was possibly related to deciding whether a conclusion correctly follows from the schema.     

Handedness, hemispheric asymmetries, and joke comprehension

To address the impact of differences in language lateralization on joke comprehension, event-related brain potentials (ERPs) were recorded as 16 left- and 16 right-handed adults read one-line jokes and non-funny control stimuli ("A replacement player hit a home run with my girl/ball,"). In right-handers, jokes elicited a late positivity 500-900 ms post-stimulus onset that was largest over right hemisphere (RH) centro-parietal electrode sites, and a slow sustained negativity over anterior left lateral sites. In left-handers, jokes elicited a late positivity 500-900 ms post-onset that was larger and more broadly distributed than in the right-handers' ERPs. In right-handed women, the late positivity was larger over RH electrode sites. In left-handed women, the late positivity was bilaterally symmetric. The highly asymmetric slow sustained negativity over left anterior electrode sites was absent from left-handers' ERPs to jokes. Differences may reflect more efficient inter-hemispheric communication in the left-handers, as they are reputed to have relatively larger corpus callosal areas than right-handers. Results support the portrait of more bilateral language representation among left-handers, and suggest language lateralization affects high-level language comprehension tasks such as joke comprehension.     

The mismatch negativity during natural sleep: intensity deviants.

Auditory event-related potentials (ERPs) were recorded from 7 subjects who slept for a single night in the laboratory. An 'oddball' sequence of brief tone pips, differing in intensity, was used. Frequently occurring 70 dB 'standards' were presented with infrequent 80 dB intensity increment deviants and 60 dB intensity decrement deviants. The probability of each deviant was 0.1. Stimuli were presented in a random sequence every 600 ms while subjects were awake but inattentive and during stages 2 and REM of sleep. During wakefulness, the intensity increments elicited a broad fronto-central negativity with two discernable peaks. The first, peaking at approximately 120 ms, showed a polarity inversion at the mastoid and likely represented a summation of the N1 wave and the mismatch negativity (MMN). The second, peaking at approximately 330 ms, may have reflected an enhanced N2b component. In REM sleep, the increment deviants elicited a small amplitude 100-200 ms negativity but its amplitude was not significantly larger than the baseline level. It was followed by a larger and significant 300-450 ms negativity but this was considered too delayed to represent the MMN. The decrement deviants elicited a small amplitude, but statistically non-significant, MMN-like wave during both wakefulness and in REM sleep. A MMN-like wave was absent in stage 2 sleep.     

An ERP study of the temporal course of the Stroop color-word interference effect

The electrophysiological correlates of the Stroop color-word interference effect were studied in eight healthy subjects using high-density Event-Related Potentials (ERPs). Three response modalities were compared: Overt Verbal, Covert Verbal, and Manual. Both Overt Verbal and Manual versions of the Stroop yielded robust Stroop color-word interference as indexed by longer RT for incongruent than congruent color words. The Incongruent vs Congruent ERP difference wave presented two effects. A first effect was a medial dorsal negativity between 350-500 ms post-stimulus (peak at 410 ms). This effect had a significantly different scalp distribution in the Verbal and Manual Stroop versions, with an anterior-medial focus for overt or covert speech, and a broader medial-dorsal distribution for the manual task. Dipole source analysis suggested two independent generators in anterior cingulate cortex. Later on in time, a prolonged positivity developed between 500-800 ms post-stimulus over left superior temporo-parietal scalp. This effect was present for all the three response modalities. A possible interpretation of these results is that Stroop color-word interference first activates anterior cingulate cortex (350-500 ms post-stimulus), followed by activation of the left temporo-parietal cortex, possibly related to the need of additional processing of word meaning.