时间知觉的注意调节：一项ERP研究

采用双任务实验范式探讨时间知觉注意调节的动态过程。通过指导语使被试按照比例将注意分配到声音刺激的时间属性与音调属性上,形成对时间因素不同注意程度的五种注意条件,同时记录反应时、错误率和事件相关电位数据。对峰值分析发现,P2注意条件主效应不显著,但多重比较时T（只注意时间）与P（只注意音调）条件差异显著;对CNV平均波幅分析,发现注意条件主效应显著,随着分配在时间属性上的注意的减少,其波幅逐渐降低;对T与P条件的差异波地形图分析发现,波幅最大的区域位于额叶、中央区和顶叶;该差异波的偶极子定位于辅助运动区（额上回、额中回）和顶下小叶。以上结果表明,P2阶段存在时间信息加工;CNV反映时间知觉的注意调节,时间知觉中存在控制加工应该以CNV的出现为指标;辅助运动区可能为时间知觉的核心成分,具有跨通道效应;顶下小叶也与对时间的注意有关,但并不是特异性的。本研究不支持Lewis提出的 “自动”与“认知控制”计时系统理论中 “秒”为两系统分界点以及辅助运动区只属于“自动计时系统”的观点     

不同时距加工机制的比较:来自ERP的证据(Ⅰ)

采用事件相关电位的方法分析了不同时距加工机制的差异。实验采用时间两分任务,要求被试形成短(400ms)和长(1600ms)的时间判断标准,然后对7个刺激系列进行短、长的判断。结果表明时间知觉过程可以诱发出一种类似于CNV的慢性负波。对于400ms的短时距加工存在显著的半球效应,右半球的波幅显著高于左半球。1600ms的时距加工没有表现出明显的半球效应。不同时距的加工存在显著的差异。1600ms比400ms加工诱发出更大的CNV波幅。     

时间心理学的新探索

时间是心理过程的存在方式,也是人格特征的存在方式。本文在综述国内外有关研究成果的基础上,对时间心理学研究的最新领域和热点问题进行了探索,主要包括三个方面：（1）时间知觉与意识,主要研究时间知觉和意识过程的关系,特别是探讨意识过程的时限和时间整合问题;（2）时间认知的脑机制,主要利用事件相关电位和脑成像技术探索时间信息加工的时程和功能定位问题;（3）时间人格研究,主要探讨时间洞察力的内涵和时间管理倾向的理论及其应用。     

1秒以上时距判断的ERP研究

以视觉呈现时距信号,采用时间泛化范式要求被试判断5种探测时距(1～4秒)与标准时距(2秒)之间的长度关系,并记录11名大学生在时距判断过程中的事件相关电位(ERP),继而探讨不同探测时距条件下CNV波幅特征变化以及左、右侧额叶在时距判断中的功能。结果发现:1秒、1.42秒以及2秒条件下,CNV波幅峰出现在探测时距结束点,2.84秒、4秒条件下,CNV波幅峰出现在大约2秒处(标准时距);CNV负性翻转至基线位置在1秒、1.42秒、2秒条件下随探测时距的增长而延后,而在2.84秒、4秒两种条件下无显著差异;左、右侧额叶处诱发的CNV波幅峰潜时在2.84秒、4秒探测时距条件下无显著差异,且均在2秒附近。这说明在1秒以上视时距判断中CNV波幅峰反映了基于记忆中标准时距的时距判断的决策过程;CNV负性翻转至基线位置与时距判断的决策阶段存在共变关系,CNV负性翻转至基线位置相当于负荷解脱过程中的一个由负翻正的转折点;左、右侧额叶均参与了时距脉冲累加过程。     

刺激性质和预测情境对负性情绪习得的影响:ERP研究

探讨刺激性质和预测情境对负性情绪习得的影响及负性情绪产生的神经机制。采用事件相关电位(ERP)技术和条件性恐惧模型,18名被试在不同预测情境中做情绪判断任务,记录与负性非条件刺激(US)匹配和与中性US匹配的条件刺激(CS)诱发的ERP,考察负性情绪的产生机制。脑电结果显示:在可预测情境下,与中性US相比,负性US联结的CS诱发的P3波幅显著降低,i CNV波幅显著升高;在不可预测情境下,负性US和中性US联结的CS诱发的P3和i CNV波幅没有显著差异。此研究结果表明,刺激性质和预测情境交互影响负性情绪反应:在可预测情境下,负性情绪的产生由US性质决定;而在不可预测情境下,负性情绪的产生由刺激出现的预测情境决定。     

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.     

面孔吸引力在认知过程中的作用及其神经机制

面孔吸引力是与进化有关的重要信息。面孔吸引力能被快速的感知,进而影响其它认知加工。近年来,学者在注意、时间知觉、学习、记忆和决策五个方面对面孔吸引力在认知过程中的作用及其神经机制做了大量研究。现有研究存在的争议主要集中于在相似的实验任务中面孔吸引力所诱发的行为反应或神经活动不同。而且以往研究在内容、技术手段和刺激材料等方面还存在可改进或扩展之处。未来研究应更多使用fMRI技术对面孔吸引力影响认知过程的脑机制进行深入探讨。     

学习困难的ERP研究

事件相关脑电位（Event—related potentials,ERPs）是研究心理学和认知神经科学的重要技术手段,将该技术用于学习困难的脑机制的研究,有助于发现学习困难的神经机制。研究表明,学习困难者的P300波幅较小,潜伏期较长。学习困难者的MMN波幅比控制组小,在信息的自动加工方面存在缺陷。在单词命名任务中,学习困难者的N400较小,而且不同类型学习困难者的波幅和潜伏期存在明显差异。     

数量加工单方向干扰时间知觉的认知与神经机制

近年来,数量加工对时间知觉的单方向干扰效应受到广泛关注,然而关于该效应的认知和神经机制的研究却缺乏深度的文献梳理和理论分析。本文从抽象数量、数字符号等认知加工如何干扰时间知觉的角度,系统总结了近期数量加工单方向影响时间知觉的研究进展;并在对相关文献加以梳理的基础上,详细分析了该效应可能的认知和神经机制,并提出若干未来研究的设想。     

时间知觉与估计的认知理论综述

本文回顾时间知觉与估计的实验研究 ,总结该领域的国内外研究结果 ,对该领域的各主要认知模型作了较全面的考察和评述 ,并进一步探讨了时间认知领域研究的今后发展 ,尤其是时间知觉与估计研究的脑电研究思路。     

聋生1秒以下与以上的视时距知觉研究

采用时距二分任务,探讨聋生在视觉通道的1s以下和1s以上时距知觉的特点。结果发现,在1s以下条件下,聋生时距判断准确性低于普通学生;聋生CNV峰值与LPCt波幅低于普通学生,CNV潜伏期短于普通学生,LPCt峰值潜伏期长于普通学生。在1s以上条件下,聋生时距判断准确性高于普通学生;聋生N1、P2、CNV与LPCt成分各项指标与普通学生均没有显著差异。这说明,听觉丧失损伤了聋生1s以下的时距记忆与决策过程,支持了普遍缺陷假设;但听觉丧失未对聋生1s以上时距加工产生显著影响,支持了感觉补偿机制。因此,时距长度在听觉丧失对视觉时距知觉的影响中具有调节作用,为时间认知的分段综合模型提供了新的支持证据。     

Motor response information influence on CNV shape and resolution time

This study systematically investigates changes in CNV waveform shape and resolution time that result from the presentation of facilitatory, inhibitory, or no motor response (MR) information simultaneously with the warning (S1) or imperative (S2) stimulus of the S1-S2-MR CNV paradigm. Analyses indicate that the simultaneous presentation of S1 and information to produce or inhibit a MR attenuates initial CNV development. Further, when the S1 information is inhibitive, CNV development is retarded throughout. The contribution of an inhibitory psychological process during CNV development is proposed. The data also indicate that CNV resolution time is not dependent on the presence of a motor response. It is suggested that CNV resolution time is indicative of psychological completion or closure.     

Three kinds of rhymes: An ERP study

In a simple prime-target visual rhyming paradigm, pairs of words, nonwords, and single letters elicited similar event-related potential (ERP) rhyming effects in young adults. Within each condition, primes elicited contingent negative variation (CNV) while nonrhyming targets elicited more negative waveforms than rhyming targets within the 320-500ms (N400/N450) time window. The target rhyming effect, apparently primarily an index of phonological processing, was similar across conditions but tended to be smaller in mean amplitude for letters. One of the first reports of such a letter rhyming effect in the ERP literature, these findings could be important developmentally because letter rhyme tasks simultaneously index the two best predictors of ease of learning to read: letter name knowledge and phonological awareness.     

GKT范式在确定犯罪嫌疑人中的应用：一项ERP测谎研究

刑事犯罪已成为当今各国面临的普遍性社会问题,因此急需可靠有效的测谎技术以适应当前打击犯罪的严峻形势。本研究采用犯罪知识测试范式（Guilty knowledge test, GKT）,以犯罪嫌疑人为对象,以真实犯罪现场为素材,探究真实环境下与测谎探测相关的脑电指标（P300、CNV）的有效性和可靠性。行为数据显示,目标刺激的反应正确率显著小于探测和无关刺激,探测刺激的反应时显著小于目标刺激和无关刺激。脑电数据显示,相较于目标刺激和无关刺激,探测刺激诱发的P300波幅最大且P300的检出率为92.5%,而在CNV指标上目标刺激诱发的波幅最大, 无关刺激次之,探测刺激最小。结果表明,与CNV相比,P300能够有效检测被试所隐藏的犯罪细节信息,且检出率较高,稳定性较好,是一种较为可靠的测谎指标。     

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.     

Influence of weight loss therapy programs in body image self-perception in adults with intellectual disabilities

Some studies suggest that people with intellectual disabilities (ID) might show distortions regarding body image self-perception. The objectives of this study were to investigate whether people with ID could correctly identify their body image and to determine if participating in a weight loss therapy program (WLTP) influenced in any way that perception. For that purpose, an experiment was proposed and all along a weight loss therapy program, a comparison between a body image subjective measure, as the Stunkard scale, and an objective one, as body mass index, was performed. The results obtained showed that individuals with ID (n = 24) perceived in a wrong way their body image before any intervention program (58%). After applying the WLTP for ten weeks, an accentuation in this perception distortion (83%), mostly related with underestimation, was observed with respect to actual body mass index values. The strongest conclusion that can be drawn from this study is that people with ID do not correctly identify their body image. Furthermore, participating in WLTP influences their physical self-concept perception in the way that controlling two variables, as exercise and caloric restriction, causes greater disruption in that perception than controlling only one of them.     

Electric source localization adds evidence for task-specific CNVs

This study was an attempt to replicate recent magnetoencephalographic (MEG) findings on human task-specific CNV sources (Basile et al., Electroencephalography and Clinical Neurophysiology 90, 1994, 157-165) by means of a spatio-temporal electric source localization method (Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 62, 1985, 32-44; Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 65, 1986, 344-360; Scherg and Berg, Brain Electric Source Analysis Handbook, Version 2). The previous MEG results showed CNV sources in the prefrontal cortex of the two hemispheres for two tasks used, namely visual pattern recognition and visual spatial recognition tasks. In the right hemisphere, the sources were more anterior and inferior for the spatial recognition task than for the pattern recognition task. In the present study we obtained CNVs in five subjects during two tasks identical to the MEG study. The elicited electric potentials were modeled with four spatio-temporal dipoles for each task, three of which accounted for the visual evoked response and one that accounted for the CNV. For all subjects the dipole explaining the CNV was always localized in the frontal region of the head, however, the dipole obtained during the visual spatial recognition task was more anterior than the one obtained during the pattern recognition task. Thus, task-specific CNV sources were again observed, although the stable model consisted of only one dipole located close to the midline instead of one dipole in each hemisphere. This was a major difference in the CNV sources between the previous MEG and the present electric source analysis results. We discuss the possible basis for the difference between the two methods used to study slow brain activity that is believed to originate from extended cortical patches.     

Slow potential changes and choice reaction time as a function of interstimulus interval

Slow potential changes were recorded over the vertex (C_z) during a choice reaction task. The constant interstimulus interval (ISI) between the visual warning (S₁) and the visual imperative signal (S₂) was either 200, 400, 1000 or 2000 msec. The contingent negative variation (CNV) was not only measured between S₁ and S₂ (CNV₂), but also before S₁ (CNV₁).The main results were: (1) The CNV₂ amplitude showed significant variation as a function of ISI. It reached its maximum with an ISI of 1000 msec. (2) CNV₁ developed only before the short ISIs (200 and 400 msec). (3) When CNV₁ and CNV₂ were summed the differences in CNV amplitudes and durations between different ISIs became smaller. (4) The peak-to-peak amplitude P₁-N₁ of the potential evoked by S₁ was enhanced with short ISIs. (5) The correlations between mean CNV and median reaction time (RT) were low but significant for ISIs of 400, 1000 and 2000 msec. When, however, the effect of subjects was partialized out these correlations were drastically reduced, whereas the partialization of session and block effects had no noticeable influence on these correlations. (6) The correlations between single RT and single CNV (measured for the ISI of 1000 msec, individually for two subjects) were weak or even completely lacking.The main conclusion was that CNV coincides with preparedness to react to a stimulus in a choice RT-task, but its amplitude at the moment of onset of the imperative stimulus does not reflect, or reflects weakly, the degree of preparedness (as indicated by RTs) at that moment.