P300和CNV在GKT的延时反应范式中测谎效果的分离

在杀人游戏情境中,设置无反馈和有反馈两个实验组,采用GKT（guilt knowledge test）的延时反应范式,考察P300和CNV两种ERP成分的测谎效果。结果发现：刺激呈现后大约450ms诱发了一个正性ERP成分（P300）,大约800ms诱发了一个负性ERP成分（CNV）。在有、无反馈两种实验范式下,P300和CNV两种测谎指标的变化情况发生了分离——有无反馈不影响P300峰值大小;而在有反馈条件下,“杀手”对于犯罪细节词语（探测刺激）的CNV明显增大。使用Bootstrap波幅差异分析法,分别计算P300和CNV在有、无反馈情况下的检出率,结果发现：两个指标的检出率在有、无反馈两种实验范式下的变化情况也发生了分离。这些结果表明：P300和CNV两个指标具有不同的测谎功能,这可能和它们所反映的不同欺骗心理过程有关。     

认知脑电技术在职务犯罪侦查中的应用探析

针对职务犯罪数量居高不下,涉案人高智商不断增高、作案方式多样且隐蔽等日益严峻的犯罪形势,脑电认知测谎技术的运用可以有效提高嫌疑人检出率,服务于职务犯罪的侦查应用之中。通过设计特定的刺激呈现方式与被测人员反应方式,以及对测试后期数据的分析,测试人员可以有效的排除无辜、认定嫌犯,达到提高办案效率的目的。相信在不久的将来,认知脑电测试法将成为辅助职务犯罪案件侦查的重要手段。     

基于自我参照编码的复合反应范式：有效鉴别有罪者和无罪知情者

隐藏信息测试在司法实践中应用受限的主要原因是容易将知道犯罪相关信息的无罪知情者误判为有罪者, 因此, 需探索有效区分有罪者和无罪知情者、有罪者和无罪不知情者的测谎技术。复合反应范式(complex trial protocol, CTP)是一种能有效抵抗反测谎的隐藏信息测试, 但尚未成功用于鉴别有罪者和无罪知情者。本研究设计了可同时测量EPN和P300的基于自我参照编码的CTP, 每个试次的第一部分随机呈现探测刺激或无关刺激, 第二部分随机呈现目标刺激(自己姓名)或非目标刺激(他人姓名), 要求被试在两个部分看到刺激时均做“与我有关”和“与我无关”的反应。结果表明, 基于自我参照编码的CTP能有效区分有罪者和无罪知情者, EPN区分有罪者和无罪知情者的鉴别力优于P300, P300区分有罪者和无罪不知情者的鉴别力优于EPN。     

测谎中反馈加工的认知神经机制：一项ERP研究

在一个模拟“杀人——侦探”游戏情境中,被试先完成模拟杀人任务,在随后的测谎阶段使用有反馈的ERP测谎范式,以反馈的形式告知被试测谎结果（“+0.5”或“-2”,分别代表“撒谎逃过检测”或“撒谎被发现”）时的脑内时程动态变化。结果发现,在反馈出现后的200～300ms时间段,表示“撒谎被抓住”比“撒谎逃过检测”的反馈信息诱发了一个更正性的ERP成分（P200-300）,在300～400ms时间段,两种反馈诱发的ERP成分（P300）没有差异,而在450～500ms时间段, “撒谎逃过检测”比“撒谎被抓住”的反馈信息诱发了一个更负性的ERP成分（N500）,负性反馈没有诱发FRN。这些结果表明：P200-300、P300和N500都是与加工测谎结果信息有关的ERP成分。P200-300可能对测谎结果的效价（正性或负性）敏感;P300可能反映被试对测谎结果主观意义大小的评价;而N500可能反映测谎结果所导致的大脑皮层兴奋程度。     

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。     

无空间线索化下视觉注意空间等级的ERP研究

采用事件相关电位技术考察无空间线索化下视觉注意资源的在不同空间等级的分布情况。在“预警信号-目标探测”范式下,目标刺激随机出现在直径视角为3.2°、6.4°以及9.6°的三个空间等级圆上。反应时结果显示：随着注意空间直径视角增大,对目标刺激的探测速度逐渐下降。脑电结果显示：三种条件下目标刺激诱发的早期N1和晚期P3成分产生了不同程度分离,主要表现为两成分的波幅随着注意空间视角增大而减小。这说明个体在无空间线索化下自动地对不同空间等级进行有选择性的资源分配。     

事件相关电位测谎技术原理探析

目前国内对于事件相关电位测谎技术的研究主要侧重于方法设计和应用探索方面,而从原理上来看,事件相关电位测谎技术主要涉及记忆的再认和欺骗反应两个认知加工过程。本研究对记忆的再认和欺骗反应这两个过程进行了分析,并总结论述了个体在这两个认知加工过程中所产生的相关脑电效应及成分(Dm效应,P300等)和相关研究,深层次阐释了事件相关电位测谎技术的原理,为进一步提高事件相关电位测谎技术的效率提供了理论支持。     

阈下情绪反馈对结果评价的影响及其性别差异

本研究用互动的决策游戏和脑电技术考察阈下情绪反馈对结果加工的影响。结果表明输钱相对于赢钱诱发更大的FRN/RewP和更小的P300,同时阈下愤怒反馈可以延缓赢钱之后下一次选择的反应时,并在女性被试中诱发更负的FRN/RewP, 但对反馈相关P300没有显著影响。这些结果说明阈下情绪反馈可影响决策结果评价早期的对刺激动机性意义的快速评估,但对晚期的深度评估没有显著影响,且这种影响在女性被试中更为明显。     

奖赏预期对面孔情绪加工的影响：一项事件相关电位研究

采用事件相关电位(ERPs)技术考察了奖赏预期对人类面孔情绪识别的影响。实验采用线索-目标范式, 分别记录了被试在奖赏预期条件下以及无奖赏预期条件下对正性、中性和负性面孔进行情绪辨别任务的ERP数据。行为结果显示, 被试在奖赏预期条件下的反应时快于无奖赏预期条件下的反应时, 对情绪面孔的反应时快于对中性面孔的反应时。ERPs数据显示, 奖赏线索比无奖赏线索诱发了更正的P1、P2和P300成分。目标刺激诱发的P1、N170波幅以及N300均受到奖赏预期的调节, 在奖赏预期条件下目标诱发了更正的ERPs。P1、N170、VPP等成分没有受到面孔情绪的影响, 而额中央位置的N300波幅显示情绪(正性与负性)面孔与中性面孔加工的差异。重要的是, N300波幅出现奖赏预期与情绪的交互作用, 正、负情绪加工效应以及负性偏向效应受奖赏预期的差异性影响。正性情绪加工效应不受奖赏预期的影响, 而负性情绪加工效应和负性偏向效应在奖赏预期条件下显著大于无奖赏预期条件下。这些结果说明, 奖赏预期能够调节对面孔情绪的加工, 且不同加工进程中奖赏对情绪加工的调节作用不同。动机性信息调节注意资源的分配, 促进了个体在加工面孔情绪时的负性偏向。     

不同戒断期海洛因戒断者情绪加工的损伤和恢复

成瘾过程伴随着一系列心理和脑机能的改变.已有研究表明,海洛因成瘾者存在对情绪刺激的加工缺陷.这些认知变化被认为与成瘾者脑内“奖赏系统”功能紊乱有关,但这种认知功能缺陷是否随着戒断进行而有所恢复还未得到明确结论.该研究采用ERP技术,记录了控制组、短期戒断组、中期戒断组和长期戒断组被试在情绪刺激加工过程中的神经电活动.结果发现,与中性刺激相比,长期组与控制组一致,正、负性刺激诱发被试更大的P300和SPW平均波幅,两类情绪刺激诱发的SPW波幅差异不显著;中期组被试的正性和负性刺激诱发的P300和SPW波幅都显著大于中性刺激,且负性刺激诱发的两成分的波幅显著大于正性刺激;短期组被试的负性刺激引起的P300和SPW波幅显著大于中性和正性刺激,但是正性和中性刺激诱发的P300或SPW波幅之间差异不显著.结果表明,随着戒断进行,海洛因戒断者情绪加工能力有所改善,主要表现在对正性情绪刺激加工能力的恢复.     

Affective recognition memory processing and event-related brain potentials

Recognition memory was examined for visual affective stimuli using behavioral and event-related brain potential (ERP) measures. Images from the International Affective Picture System (IAPS) that varied systematically in arousal level (low, high) and valence direction (unpleasant, pleasant) were first viewed passively. Then, during a response phase, the original images were intermixed with an equal number of new images and presented, and participants were instructed to press a button to indicate whether each stimulus picture was previously viewed (target) or new (foil). Participants were more sensitive to unpleasant- than to pleasant-valence stimuli and were biased to respond to high-arousal unpleasant stimuli as targets, whether the stimuli were previously viewed or new. Response times (RTs) to target stimuli were systematically affected by valence, whereas RTs to foil stimuli were influenced by arousal level. ERP component amplitudes were generally larger for high than for low arousal levels. The P300 (late positive component) amplitude was largest for high-arousal unpleasant target images. These and other amplitude effects suggest that high-arousal unpleasant stimuli engage a privileged memory-processing route during stimulus processing. Theoretical relationships between affective and memory processes are discussed.     

Predicting the Sensitivity of the Reaction Time‐based Concealed Information Test

Current lie detection and memory detection tests are imperfect. One possibility is that they work in some individuals but not in others. Here, we investigate whether we can statistically predict the accuracy of the Concealed Information Test (CIT). We examined the CIT's potential by (1) its sensitivity on an unrelated set of autobiographic questions and by (2) using mock crime target‐irrelevant differences. A mock crime CIT that included autobiographical questions was used to detect criminal intent. The mock crime CIT discriminated (receiver operating characteristic a = .87; d = 1.25; hit rate: 86%) between the criminal intent and the control condition. Using target‐irrelevant differences, but not the autobiographical questions, successfully screened out individuals and increased the CIT's accuracy (receiver operating characteristic a = .95; d = 1.67; hit rate: 97%). Our study provides preliminary evidence that we can predict for whom the CIT is likely to work and that this information can be used to increase detection efficiency. Copyright © 2013 John Wiley & Sons, Ltd.     

Consciousness of attention and expectancy as reflected in event-related potentials and reaction times

The effects of conscious expectancies and attention on event-related potentials (ERP) and choice reaction times (RT) and their modulation by stimulus sequence were studied. Subjects retrospectively reported their expectancy of, and attention to, the terminal tones of short series. ERPs and RTs showed the usual sequential effects that were modulated by practice. As ratings were affected by only a few of the stimulus sequence, conscious access to sequence-based expectancy or attention appears to be fragmentary. Increased P300 amplitude with attention indicates conscious access to processing capacity. RTs and P300 latencies suggest stimulus processing time to decrease with sequence-based and consciously accessible expectancy. Differential effects of stimulus sequences and conscious expectancies on P300 amplitude indicate influences of two varieties of expectancy.     

Anticipatory attention during the sleep onset period

To examine whether anticipatory attention or expectancy is a cognitive process that is automatic or requires conscious control, we employed a paired-stimulus event-related potential (ERP) paradigm during the transition to sleep. The slow negative ERP wave observed between two successive stimuli, the Contingent Negative Variation (CNV), reflects attention and expectancy to the second stimulus. Thirteen good sleepers were instructed to respond to the second stimulus in a pair during waking sessions. In a non-response paradigm modified for sleep, participants then fell asleep while tones played. As expected, N1 decreased and P2 increased in amplitude systematically with the loss of consciousness at sleep onset; the CNV was increasingly more positive. Sleep onset latency was correlated with the amplitude of the CNV. The systematic attenuation of the CNV waveform at sleep onset and its absence in sleep indicates that anticipatory attention requires endogenous conscious control.     

ERPs associated with visual duration discriminations in prefrontal and parietal cortex

An event-related potentials (ERP) study was undertaken to examine the role of prefrontal and parietal association cortices on selective attention and short-term memory functions in a duration discrimination task. Subjects performed better when discriminating the first stimulus relative to the second and not the reverse. Two contingent negative variations (CNV) were obtained for each stimulus duration at prefrontal regions, as well as two P300s at parietal regions. The CNV(S1) component recorded during the first stimulus (S1) appeared to be involved in selective attention at bilateral sites, while the P300(S1) component in the left hemisphere may be implicated in retaining it. The CNV(S2) wave, displayed during the second stimulus (S2), at bilateral sites and the right-sided P300(S2) wave seem to be implicated in working memory. The results indicate that recorded activity at prefrontal and parietal association cortices is tightly linked to task parameters and behavioral performances.     

Psychopathy and Event-Related Brain Potentials (ERPs) associated with attention to speech stimuli

Event-related brain potentials (ERPs) were used to determine whether low left-hemisphere arousal or unusual cortical responses to speech stimuli might be associated with anomalies in language function that reportedly occur when psychopaths perform lateralized information-processing tasks. ERPs to phonemic stimuli were recorded while 11 psychopathic (P) and 13 nonpsychopathic (NP) male prison inmates performed a Single-Task and a Dual-Task. In the Single-Task, a speech discrimination ‘oddball’ paradigm, the subject was required to respond whenever a target stimulus (the less frequent of two phonemes) occured. In the Dual-Task, he had to respond to target stimuli while simultaneously performing a perceptual-motor (distractor) task. There were no group differences in ERP measures of central arousal (N100) during performance of the Single- and Dual-Tasks. For both groups, the P300 component of the ERP to the target stimulus was smaller and had longer latency during the Dual-Task than during the Single-Task, indicating that in the Dual-Task phonemic discrimination and the perceptual-motor task completed for similar perceptual resources. Overlapping Group P's P300 responses to the target stimulus during the Dual-Task was a vertex and asymmetric (left-hemisphere) positive slow wave (SW), suggesting unusual speech processing in psychopaths under conditions of distraction, perhaps related to reduced sensitivity to the sequential probabilities associated with events presented in an auditory channel. The results were consistent with the hypothesis that psychopaths have limited left-hemisphere resources for processing linguistic stimuli.     

P300 stimulus sequence effects in children and adults

Immediate memory capability for 12 children (8 years) and 12 adults (21 years) was assessed electrophysiologically by using P300 event-related brain potential (ERP) stimulus sequences. These were derived from an auditory discrimination paradigm in which participants detected target stimuli in a series of target (T) and standard (S) tones that were varied by randomly presenting one of four sequence patterns (SSSS, TTTT, TTTS, SSST). Short-term memory capability was assessed behaviorally by recall performance of a 20-word list. Children and adults showed virtually identical P300 amplitude sequence patterns, such that for both groups component size increased systematically as the discrepancy between standard and target stimuli increased across sequence patterns. P300 latency evinced similar, albeit weaker, stimulus sequence effects, with children having longer component peak latencies. Memory recall performance was substantially weaker for the children than for adult participants, especially for recency effects. The findings suggest that immediate memory for stimulus sequences is fully developed in young children, although long-term memory is not.     

Where has all the inhibition gone? Insights from electrophysiological measures into negative priming without probe distractors

Responses to probe targets that have been distractors in a prime display are slower than responses to unrepeated stimuli, a finding labeled negative priming (NP). However, without probe distractors the NP effect usually diminishes. The present study is the first to investigate ERP correlates of NP without probe distractors to shed light on the processes underlying NP. Based on existing findings in the field, we analyzed two ERP correlates that have been associated with the visual NP effect so far, namely the N200 and the P300. As expected, no behavioral NP effect as well as no N200 modulation emerged. However, the P300 component was enhanced when a prime distractor was repeated as the probe target. This effect is interpreted as reflecting automatic retrieval of the prime episode occurring independently of the presence of probe distractors.