反应与刺激冲突的脑机制差异:来自ERP研究的证据

采用事件相关电位技术(ERP),用侧抑制任务探讨了刺激和反应冲突的脑内时程动态变化。行为数据表明,冲突条件的反应时显著长于无冲突条件,表现出明显的干扰效应;脑电数据表明,在300-450ms内,反应冲突比无冲突诱发了一个更负的ERP成分(N300-450),主要分布于额顶部,偶极子溯源分析发现,这一负成分可能主要源于ACC;而刺激冲突与无冲突相比在350-450ms内,也诱发了一个更负的ERP成分(N350-450),该负成分可能主要源于丘脑附近。这一结果表明,刺激与反应冲突所涉及的大脑机制可能并不相同。     

猜谜作业中顿悟的ERP效应

采用事件相关电位(ERP)探索问题解决过程中顿悟的神经机制。以猜谜作业为实验程序,对“有顿悟”和“无顿悟”答案引发的脑电分别进行叠加和平均,并将二者相减（有顿悟-无顿悟）得到差异波。在250~500 ms “有顿悟”比“无顿悟”的ERP波形有一个更加负性的偏移,在差异波中,这个负成分的潜伏期约为380 ms（N380）。地形图和电流密度图显示,N380在额中央区活动最强。偶极子源定位分析结果显示,N380可能起源于扣带前回。因此,N380可能反映顿悟问题解决过程中思维定势的突破。     

网络语言的创造性加工过程:新颖N400与LPC

采用事件相关电位(ERP)技术比较在语义违反范式下网络语言和标准汉语的语义加工差异。结果发现:(1)不管是网络语言还是标准汉语,相对于语义一致条件,语义不一致条件在400 ms诱发了一个更负的负成分,但网络语言的经典N400差异波具有更晚的潜伏期和更长的持续时间;(2)溯源结果发现,网络语言和标准汉语的经典N400差异波的早期和晚期的定位均分别定位于丘脑和前扣带回,表明N400延迟效应是由个体对网络语言相对低的流利度所致,反映了认知冲突的延续;(3)在语义一致性条件下,网络语言比标准汉语诱发了一个更负的新颖N400和一个更正的晚期正成分(LPC),分别定位于前扣带回和海马,二者分别反映了新颖网络含义的识别以及新颖语义信息的整合与新颖语义联结的形成。ERP结果支持了网络语言加工属于创造性思维过程。     

Tracking the implicit self using event-related potentials

Negative biases in implicit self-evaluation are thought to be detrimental to subjective well-being and have been linked to various psychological disorders, including depression. An understanding of the neural processes underlying implicit self-evaluation in healthy subjects could provide a basis for the investigation of negative biases in depressed patients, the development of differential psychotherapeutic interventions, and the estimation of relapse risk in remitted patients. We thus studied the brain processes linked to implicit self-evaluation in 25 healthy subjects using event-related potential (ERP) recording during a self-relevant Implicit Association Test (sIAT). Consistent with a positive implicit self-evaluation in healthy subjects, they responded significantly faster to the congruent (self–positive mapping) than to the incongruent sIAT condition (self–negative mapping). Our main finding was a topographical ERP difference in a time window between 600 and 700 ms, whereas no significant differences between congruent and incongruent conditions were observed in earlier time windows. This suggests that biases in implicit self-evaluation are reflected only indirectly, in the additional recruitment of control processes needed to override the positive implicit self-evaluation of healthy subjects in the incongruent sIAT condition. Brain activations linked to these control processes can thus serve as an indirect measure for estimating biases in implicit self-evaluation. The sIAT paradigm, combined with ERP, could therefore permit the tracking of the neural processes underlying implicit self-evaluation in depressed patients during psychotherapy.     

概率贴现和时间贴现在人脑中的分离

本研究运用ERP技术来检验概率贴现和时间贴现是否反映了相同的神经机制过程。在本研究中,我们在一个刺激中同时操纵概率贴现（风险vs.安全）和时间贴现（1个月后vs.今天）水平。通过对两个过程上的ERN以及全时间段的ERP分析来确定它们是否反映了相同的认知过程。结果发现,这两者在ERN上存在差异,同时这两个效应在ERP的时程和出现的电极点上都存在差异。这些差异表明这两者可能包含着不同的神经机制过程。     

Imageability and semantic association in the representation and processing of event verbs

This study examined the relative salience of imageability (the degree to which a word evokes mental imagery) versus semantic association (the density of semantic network in which a word is embedded) in the representation and processing of four types of event verbs: sensory, cognitive, speech, and motor verbs. ERP responses were recorded, while 34 university students performed on a lexical decision task. Analysis focused primarily on amplitude differences across verb conditions within the N400 time window where activities are considered representing meaning activation. Variation in N400 amplitude across four types of verbs was found significantly associated with the level of imageability, but not the level of semantic association. The findings suggest imageability as a more salient factor relative to semantic association in the processing of these verbs. The role of semantic association and the representation of speech verbs are also discussed.     

Statistical significance tests for binormal ROC curves

Statistical significance tests are derived and evaluated for measuring apparent differences between an obtained and an expected binormal ROC curve, between two independent binormal ROC curves, and among groups of independent binormal ROC curves. A binormal ROC curve is described by two parameters which represent the spread of the means and the ratio of the standard deviations of the two underlying Gaussian decision variable distributions. To test the significance of apparent differences between or among ROC curves, approximate χ² statistics for each of the three tests were constructed from maximum likelihood estimates of the two parameters defining the binormal ROC curve. The performance of each test statistic was evaluated by simulating five-category rating scale data with equal numbers of noise and signal-plus-noise trials (set at 50, 250, and 500) for each of three typical ROC curves. For the significance test involving only one ROC curve, rating scale data were generated from the chance diagonal of the ROC space also. Although test performance was found to be somewhat dependent on the number of trials and on the location of the ROC curve in the ROC space, comparisons of the obtained and expected fractions of (falsely) significant results at various α levels showed the proposed statistical significance tests to be reliable under practical experimental conditions.     

Event‐related potentials reveal linguistic suppression effect but not enhancement effect on categorical perception of color

The present study used the event‐related potential technique to investigate the nature of linguistic effect on color perception. Four types of stimuli based on hue differences between a target color and a preceding color were used: zero hue step within‐category color (0‐WC); one hue step within‐category color (1‐WC); one hue step between‐category color (1‐BC); and two hue step between‐category color (2‐BC). The ERP results showed no significant effect of stimulus type in the 100‐200 ms time window. However, in the 200–350 ms time window, ERP responses to 1‐WC target color overlapped with that to 0‐WC target color for right visual field (RVF) but not left visual field (LVF) presentation. For the 1‐BC condition, ERP amplitudes were comparable in the two visual fields, both being significantly different from the 0‐WC condition. The 2‐BC condition showed the same pattern as the 1‐BC condition. These results suggest that the categorical perception of color in RVF is due to linguistic suppression on within‐category color discrimination but not between‐category color enhancement, and that the effect is independent of early perceptual processes.     

女性对新异性事件加工的偏向:来自ERP的证据

采用修订后的oddball范式,结合ERP技术考察女性与男性在加工中性新异刺激时的差异。ERP结果表明,在早期已经出现新异性效应。在300-500ms内,新异刺激在男性和女性被试中都比标准刺激诱发了更大的LPC。在500-700ms内,新异刺激仅在女性被试中比标准刺激诱发更大的LPC,在男性被试中没有显著差异。这些结果表明男性和女性都对中性新异刺激表现出加工偏向,但是女性对其加工的时间比男性更长。这可能与女性容易对显著性(salient)的刺激进行沉思(rumination)相关。     

Automatic change detection in vision: Adaptation,memory mismatch,or both? II: Oddball and adaptation effects on event-related potentials

In this study we compared the event-related potentials (ERPs) obtained in two different paradigms: a passive visual oddball paradigm and an adaptation paradigm. The aim of the study was to investigate the relation between the effects of activity decrease following an adaptor (stimulus-specific adaptation) and the effects of an infrequent stimulus within sequences of frequent ones. In Experiment 1, participants were presented with different line textures. The frequent (standard) and rare (deviant) texture elements differed in their orientation. In Experiment 2, windmill pattern stimuli were presented in which the number of vanes differentiated the deviant and standard stimuli. In Experiment 1 the ERP differences elicited between the oddball deviant and the standard were similar to the differences between the ERPs to the nonadapted and adapted stimuli in the adaptation paradigm. In both paradigms the differences appeared as a posterior negativity with the latency of 120–140 ms. This finding demonstrates that the representation of a sequential rule (successive presentation of the standard) and the violation of this rule are not necessary for deviancy effects to emerge. In Experiment 2 (windmill pattern), in the oddball paradigm the difference potentials appeared as a long-lasting negativity. In the adaptation condition, the later part of this negativity (after 200 ms) was absent. We identified the later part of the oddball difference potential as the genuine visual mismatch negativity—that is, an ERP correlate of sequence violations. The latencies of the difference potentials (deviant minus standard) and the endogenous components (P1 and N1) diverged; therefore, the adaptation of these particular ERP components cannot explain the deviancy effect. Accordingly, the sources contributing to the standard-versus-deviant modulations differed from those related to visual adaptation; that is, they generated distinct ERP components.     

Mental body distance comparison: A tool for assessing clinical disturbances in visual body image

Despite numerous body size estimation studies, it cannot be concluded that the disturbance of body image in anorexia nervosa (AN) is specifically one of the visual body images.We adopted a visual imagery method, the Distance Comparison task, to enable across-population testing of differences in visual body image with respect to shape. Participants were asked to mentally scan across two body widths (e.g. hips and shoulders) and to decide as quickly as possible which one was longer or shorter. If the mental representation accessed to make such comparisons is visual, an inverse relation would be expected between RT and distance difference on the body to be judged (i.e. actual difference in size between the two body widths), with accuracy increasing with increasing distance difference. Females with high body shape concern (scoring high on the Body Shape Questionnaire: BSQ, n = 23) were compared to females with low body shape concern (scoring low on the BSQ, n = 19).RT and distance differences on the body demonstrated standard distance differences effects: RT increased and accuracy decreased with decreasing distance differences on the body. Groups differed with respect to accuracy, in that females high on body shape concern were significantly less accurate than females low on body shape concern when making evaluations involving small (?9 cm) differences, which implies a less appropriate visual image of the own body in the former group. With respect to the relation between RT and body distance difference, on the other hand, there were no differences between groups. We concluded that evaluations of own body size employ visual imagery and that the distance comparison task holds promise for the assessment of visual disturbances in body image in clinical populations.     

类别归纳的时间过程和源定位 ——事件相关电位研究提供的电生理证据

采用事件相关电位（ERP）技术,以图形比较为实验作业探索类别归纳的神经机制。任务要求被试归纳两个图形刺激之间的共享特征,根据共享特征数量的不同构成三个任务：共享一个特征（S1F）、共享两个特征（S2F）和共享三个特征（S3F）。S1F任务和S2F任务被看作“归纳”任务,S3F任务被看作“非归纳”任务。对三个任务诱发的脑电分别进行叠加和平均,通过相减技术得到差异波（S1F－S3F,S2F－S3F）。在400到650ms时间窗口三个条件均诱发了LPC成分,地形图显示三个条件下LPC的头皮分布均出现在中－顶;两个“归纳”任务与“非归纳”任务在LPC上存在显著差异,而两个“归纳”任务在LPC上没有显著差异。对两个差异波在400到650ms时段的数据进行偶极子源分析,结果显示每个差异波均只有一个偶极子源,且二者定位相似（均在海马附近）。由于已知海马与新异联系的形成有关,因此LPC可能反映了类别归纳的关键加工——新异联结的形成     

情绪对不同外倾水平个体行为抑制的影响

采用双选择oddball实验范式与事件相关电位（ERP）技术,探讨了情绪对行为抑制的影响以及外倾性的调节作用。行为数据发现,相比标准刺激,被试对偏差刺激的反应时显著更慢,证明实验成功诱发了行为抑制效应。在内倾组,负性刺激下偏差与标准刺激反应时差值显著长于正性刺激条件,而在外倾组无显著差异。脑电数据发现,在N2成分上,内倾组在正性情绪下的波幅显著小于负性和中性情绪,而在外倾组,不同情绪下的波幅不存在显著差异。在P3成分上,内倾组在正性情绪下的波幅显著大于负性和中性情绪,相反,外倾组在负性情绪下的波幅显著大于正性和中性情绪。结果表明,情绪对行为抑制的影响受到了个体外倾性水平的调节。     

关于知觉干扰效应的ERP研究

利用ERP技术,采用知觉干扰效应的经典实验范式,首次从神经生理水平上探究知觉干扰效应的内部机制。结果发现,递进条件和标准条件均诱发了P2,P3,N400和晚期正成分LPC。在P2,P3和LPC成分上,标准条件的波幅均显著大于递进条件;在N400成分上,递进条件比标准条件波幅更负,潜伏期更长。此外,对递进条件下靶字各模糊水平（Level 1～Level 5）的ERPs进行比较分析表明,N400成分的波幅在各模糊水平间的差异均不显著。基本支持失匹配理论及词汇自动加工理论。     

Re-evaluating the Time Course of Gender and Phonological Encoding During Silent Monitoring Tasks Estimated by ERP: Serial or Parallel Processing?

Neurolinguistic and psycholinguistic studies suggest that grammatical (gender) and phonological information are retrieved independently and that gender can be accessed before phonological information. This study investigated the relative time courses of gender and phonological encoding using topographic evoked potentials mapping methods. Event-related brain potentials (ERPs) were recorded using a high resolution electroencephalogram (EEG) system (128 channels) during gender and phoneme monitoring in silent picture naming. Behavioural results showed similar reaction times (RT) between gender and word onset (first phoneme) monitoring, and longer RT when monitoring the second syllable onset. Temporal segmentation analysis (defining dominant map topographies using cluster analysis) revealed no timing difference between gender monitoring and word onset monitoring: both effects fall within the same time window at about 270–290 ms after picture presentation. Monitoring a second syllable onset generated a later effect at about 480 ms. Direct comparison between gender and first phoneme monitoring revealed a difference of only 10 ms between tasks at approximately 200 ms. Taken together, these results suggest that lemma retrieval and phonological encoding may proceed in parallel or overlap. Word onset is retrieved simultaneously with gender, while the longer RT and the later ERP effect for second syllable onset reflect that segmental encoding continues incrementally to the following phonemes.     

Estimating and Testing the Sources of Evoked Potentials in the Brain

The source of an event related brain potential (ERP) is estimated from multivariate measurements of this ERP on the head under several mathematical and physical constraints on the parameters of the source model. We will discuss statistical aspects of standard methods to estimate these parameters and their confidence intervals. In addition new principled tests of the goodness of fit as well as of differences between estimated sources are proposed and compared with customary approaches in psychophysiology. Several factors which influence the statistical analysis, in particular the number of measurement leads, will be discussed.     

Are event-related potentials to dynamic facial expressions of emotion related to individual differences in the accuracy of processing facial expressions and identity?

Despite a wealth of knowledge about the neural mechanisms behind emotional facial expression processing, little is known about how they relate to individual differences in social cognition abilities. We studied individual differences in the event-related potentials (ERPs) elicited by dynamic facial expressions. First, we assessed the latent structure of the ERPs, reflecting structural face processing in the N170, and the allocation of processing resources and reflexive attention to emotionally salient stimuli, in the early posterior negativity (EPN) and the late positive complex (LPC). Then we estimated brain–behavior relationships between the ERP factors and behavioral indicators of facial identity and emotion-processing abilities. Structural models revealed that the participants who formed faster structural representations of neutral faces (i.e., shorter N170 latencies) performed better at face perception (r = –.51) and memory (r = –.42). The N170 amplitude was not related to individual differences in face cognition or emotion processing. The latent EPN factor correlated with emotion perception (r = .47) and memory (r = .32), and also with face perception abilities (r = .41). Interestingly, the latent factor representing the difference in EPN amplitudes between the two neutral control conditions (chewing and blinking movements) also correlated with emotion perception (r = .51), highlighting the importance of tracking facial changes in the perception of emotional facial expressions. The LPC factor for negative expressions correlated with the memory for emotional facial expressions. The links revealed between the latency and strength of activations of brain systems and individual differences in processing socio-emotional information provide new insights into the brain mechanisms involved in social communication.     

Therapists’ Thought-Action Fusion Beliefs Predict Utilization of Exposure in Obsessive-Compulsive Disorder

Although exposure and response prevention (ERP) is considered the gold standard for the treatment of obsessive-compulsive disorder (OCD), it is rarely used in clinical practice. Therapists’ beliefs about ERP affect its utilization, as previous research suggests, but the role of therapists’ cognitive biases is unclear. In particular, susceptibility to thought-action fusion (TAF) may be related to the underutilization of ERP in OCD.Therapists (N = 353) were divided into those recommending (ERP+, n = 228) and not recommending ERP (ERP−, n = 125) as treatment for an OCD case example. TAF in therapists was assessed using behavioral and self-report measures (TAFS).TAF was higher in the ERP− than the ERP+ group, with a small to moderate effect size (0.2 ≤ d ≤ 0.4). ERP− therapists showed more avoidance and neutralizing behavior and a stronger emotional response than the ERP+ therapists during the experimental task. Moreover, higher TAF as measured by the TAFS was associated at a small magnitude with lower likelihood of using ERP in the therapists’ actual clinical practices.Therapists’ cognitive biases should be addressed in their training in order to increase the dissemination of evidence-based treatment (i.e., ERP) and thus improve the treatment of OCD.     

Age difference in numeral recognition and calculation: an event-related potential study.

In this study, we investigated the age difference in numeral recognition and calculation in one group of school-aged children (n = 38) and one of undergraduate students (n = 26) using the event-related potential (ERP) methods. Consistent with previous reports, the age difference was significant in behavioral results. Both numeral recognition and calculation elicited a negativity peaking at about 170-280 ms (N2) and a positivity peaking at 200-470 ms (pSW) in raw ERPs, and a difference potential (dN3) between 360 and 450 ms. The difference between the two age groups indicated that more attention resources were devoted to arithmetical tasks in school-aged children, and that school-aged children and undergraduate students appear to use different strategies to solve arithmetical problems. The analysis of frontal negativity suggested that numeral recognition and mental calculation impose greater load on working memory and executive function in schoolchildren than in undergraduate students. The topography data determined that the parietal regions were responsible for arithmetical function in humans, and there was an age-related difference in the area of cerebral activation.     

单维测验合成信度三种区间估计的比较

已有许多研究建议使用合成信度来估计测验信度, 并报告其置信区间。有三种方法或途径可以计算单维测验合成信度的置信区间, 包括Bootstrap法、Delta法和直接用统计软件(如LISREL)输出的标准误进行计算。本文通过模拟研究进行比较, 发现Delta法与Bootstrap法得到的置信区间相当接近, 但用LISREL输出的标准误计算的与Bootstrap法得到的结果相差很大。推荐用Delta法估计合成信度的置信区间(使用Mplus容易实现), 但不能直接用LISREL输出的标准误来计算。举例说明了如何计算单维测验的合成信度以及用Delta法计算其置信区间。