女性主观性唤起状态下的听觉事件相关电位研究

目的:研究性感听觉材料引起的女性主观性唤起状态的听觉事件相关电位特征。方法:编制性感听觉材料;用主观性唤起多元评价指标调查广告招募的30名女性聆听性感听觉材料后的主观性唤起状态;应用德国Brain-Product,BP-ERP工作站,测量并分析25名女性由纯音、放松音乐及性感听觉材料引发的听觉事件相关电位;采用单个重复测量因素方差分析的方法对P3潜伏期进行分析,采用多个相关样本的非参数检验的方法对P3波幅作分析。结果:(1)主观性唤起多元评价指标显示被试听性感听觉材料后达到轻中度主观性唤起水平;(2)性感听觉材料背景下多导联P3波幅低于放松音乐背景;两者潜伏期差异无统计学意义;(3)Odd-ball范式被试报告靶刺激的正确率在性感听觉材料背景下最低。结论:性感听觉材料能引起女性主观性唤起;女性在主观性唤起状态时P3波幅明显降低,比一般的放松状态更集中于对自身的体验。     

靶与非靶刺激信息的认知事件相关电位比较

对靶与非靶刺激信息的认知事件相关电位进行比较研究。给予受试者汉语词汇作业刺激，被视觉感知，靶刺激以２０％的概率随机呈现，非靶刺激占８０％。结果发现这两种刺激状态下认知事件相关电位成分的Ｎ１，Ｐ２，Ｎ２无显著差异，而Ｐ３，Ｎ４和ＬＰＣ（ＬａｔｅＰｏｓｉｔｉｖｅＣｏｍｐｏｎｅｎｔ）则其波形变化和地形图特征有明显不同，靶刺激激活整个脑区，各波幅均较大，以Ｐ３波最为显著     

不同手按键对事件相关电位的影响

对30名正常青年人分别采用左、右手按键测定听觉事件相关电位(ERP)。我们发现,当靶刺激或非靶刺激出现时,不同的手按键,各导联诱发的P_3或P_2波的潜伏期无明显差异(P>0.05),但当靶刺激出现时,不同的手按键能引起按键手对侧半球后部P_3波电位值的降低,而颅顶中线各导联之P_3波电位值无明显差异。     

注意缺陷多动障碍儿童在不同情绪面孔刺激下的持续注意任务事件相关电位

目的:了解不同情绪面孔刺激下注意缺陷多动障碍(ADHD)患儿执行持续注意任务时的事件相关电位特征。方法:选取符合美国精神障碍诊断与统计手册第4版(DSM-IV)诊断标准的混合型ADHD患儿32例(年龄9~15岁)及年龄、性别匹配的正常对照组儿童32例,要求被试在高兴、中性、恐惧和愤怒等4种情绪面孔刺激随机呈现后执行注意与选择任务,同时记录事件相关电位。观察ADHD患者和正常对照组儿童面孔诱发的N170电位及靶刺激诱发的P300电位的特征。结果:ADHD组患儿在4种不同情绪面孔刺激下颞枕区面孔特异性N170波波幅均低于对照组[如恐惧面孔,(17.7±9.5)μv vs.(25.8±14.0)μv,P0.05],顶枕区P300潜伏期长于对照组[如恐惧面孔,[(454.2±51.3)ms vs.(433.0±29.8)ms,P0.05]。ADHD患儿组在四情绪面孔诱发的N170波幅和潜伏期差异无统计学意义(P0.05),诱发的P300在四种情绪刺激中以恐惧面孔刺激后执行注意任务的P300波幅最低,潜伏期最长。结论:ADHD儿童在4种不同情绪面孔刺激下,以恐惧面孔刺激引起的P300波幅最低,且P300潜伏期延长最明显。提示恐惧面孔可能影响ADHD患儿情绪调节,并影响其持续注意过程。     

注意对冲突监测事件相关电位N270的影响

目的：探讨注意对冲突监测事件相关电位N270的影响。方法：30名健康志愿者分成两组,一组人判断连续呈现的一对数字的颜色是否相同,不考虑数值（注意颜色）;另一组人判断连续呈现的一对数字的数值是否相同,不考虑颜色（注意数值）,在头皮同步记录事件相关电位。结果：颜色不同和／或数值不同的数字对均可在第二个数字呈现后引起事件相关电位N270,颜色和数值完全相同的数字对则不引起该负波。与不被主动注意状态相比,刺激特征冲突被注意时引出的N270波幅更高,持续时间更长,起始潜伏期不变。结论：冲突监测系统的启动不受注意影响,而一旦启动后则受到注意系统的调节。     

首发精神分裂症女性患者雌激素与事件相关电位的相关性

目的：研究首发精神分裂症女性患者雌激素与事件相关电位（ERP）P300的关系。方法：采用放射免疫法测定30例首发精神分裂症女性患者（患者组）与20名正常女性（对照组）的血清雌激素水平;并用ERPP300（即P3波）评定患者认知功能。结果：①患者组雌二醇（E2）水平低于对照组,差异有统计学意义（P〈0．05）;②与正常对照组比较,患者组靶刺激N1、N2和P3波及非靶刺激P2波潜伏期延迟,靶刺激P3波及非靶刺激P2波波幅降低;③患者组E2水平与P300潜伏期呈显著负相关（r=-0．43,P=0．02）。结论：首发精神分裂症女性患者存在雌激素水平下降,以及注意力、记忆力缺陷和认知加工缓慢等认知障碍,雌激素水平与认知功能呈显著相关。     

健康人事件相关电位及心理学相关性研究

目的：探讨不同年龄健康人听觉事件相关电位（ERP）及其与心理测验间关系。方法：对不同年龄组健康者进行听觉ERP检测，以"oddball序列"刺激从Cz点引出P3，测其波幅和潜伏期。对其中30名成人进行韦氏智力量表和记忆量表测验。结果：P3潜伏期以儿童期最短，并随年龄增长逐渐延长，P3波幅儿童期明显高于成年人。成年组P3潜伏期与总智商、记忆商、及某些分测验呈显著负相关，而P3波幅与心理测验无明显相关关系。结论：不同年龄者ERP正常值不同，ERP能够反映智能的某些方面，特别倾向于反映言语和记忆能力。     

正常青年人视觉、听觉诱发的ERP的比较

35例正常青年人同时进行视觉、听觉不同刺激模式检测的事件相关电位(ERP)进行比较分析,我们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,尤其是不同模式的靶与非靶刺激诱发的P_2波的波幅有明显的差距(P<0.05)。本文对其原因和不同年龄的P_3波在颅顶有不同的分布部位以及其中一些人P_3波电位值两半球不对称性的机理进行了初步探讨。     

性别因素对老年期神经系统变性过程的影响

目的：研究探讨正常人进入老年期后，性别和年龄对事件相关电位的交互作用影响是否仍然持续。方法：应用神经心理学测试和MRI检查筛选日本冲绳县年龄在60岁以上的正常老年人40名。其中男性17名，平均年龄是72．2±8．6岁；女性23名，平均年龄是75．7±8．2岁。应用听觉“oddball”范式诱发事件相关电位P300。分析Fz和Pz部位记录到的事件相关电位内源性成分P300和N2b。结果：P300潜伏期、P300波幅和N2b潜伏期的组间差异不显著。于Fz部位，男性组的N2b波幅低于女性组（F=4．59，P=0．039）。P300潜伏期和P300波幅与年龄的相关性，仅见于男性组（Fz-P300潜伏期：r=0．584，P=0．014；Fz-P300波幅：r=-0．782，P〈0．001；Pz—P300潜伏期：r=0．587，P=0．013；Pz—P300波幅：r=-0．657，P=0．004）。P300潜伏期和P300波幅对年龄的线性回归坡度，在两组闾均有显著性差异，在男性组更为陡峭（Fz—P300潜伏期：t=2．11，P=0．042；Fz-P300波幅：t=2．55，P=0．015；Pz-P300潜伏期：t：2．70，P=0．011：Pz-P300波幅：t=3．00，P=0．005）。结论：性别因素对老年期神经系统变性过程有显著影响。     

特质焦虑人群应激条件下ERP中P3的变化

目的：探讨不同特质焦虑大学生应激条件下的ERP特点。方法：以大学英语四级考试为应激源，应用特质-状态焦虑量表在200名考生中，筛选高特质焦虑和低特质焦虑各15人，使用NeuroScan 32 Channel ERP System观察应激期和应激后P3变化。结果：①低特质焦虑组应激后P3波幅大于应激期（P〈0．05），潜伏期小于应激期。②高特质焦虑组应激期和应激后相比，P3波幅、潜伏期无变化。③应激时，高、低特质焦虑组P3波幅、潜伏期无明显差异。④应激后，低特质焦虑组P3波幅大于高特质焦虑组、潜伏期小于高特质焦虑组（P〈0．05）。结论：高、低特质人群的P3差异提示不同人格特质群体在相同应激事件中，认知功能有差异。     

Can subitizing survive the attentional blink? An ERP study

This study was done to test whether subitizing versus counting are attention demanding based on whether they can be performed during the attentional blink (AB). ERPs were recorded while participants performed a task requiring them to judge the number of dots presented and this judgment task either followed the presentation of a task-relevant item in a rapid stimulus presentation stream (dual-task) or the potential target was task irrelevant (single-task). The behavioral data demonstrated that T2 accuracies decreased as a function of the number of dots not only in counting range, but also in subitizing range. The ERP results showed a delayed P3 component in the dual-task condition, and this was equally true for both subitizing and counting conditions. Furthermore, the P3 amplitude was reduced during the AB, and this was still equally true for both the subitizing and counting conditions. The present results suggest that both subitizing and counting require attention, and that subitizing is not a purely pre-attentive process.     

On the validity of interblock averaging of P300 in clinical settings.

The reduction of long-latency auditory ERPs amplitude, including P300, to repeated stimuli has been well documented in the literature on habituation. The effect of block repetition on auditory ERPs recorded for clinical purposes, where interblock intervals are commonly longer than those employed in habituation studies, was studied in a sample of 38 adults submitted to two blocks of a counting oddball paradigm. Four different experimental conditions were considered, differing in target probability, delivery or not of a previous passive oddball tone sequence, and the performance or not of other oddball tasks requiring more complex discriminative responses between the two blocks. Results showed that: (1) N1 amplitude to the frequent non-target stimuli decreased in the second block under all the conditions; (2) when the two blocks were consecutive (separated by 2-3 min), P300 amplitudes were unaffected by block repetition, this whatever the probability of the target (25% vs. 10%) and whether or not a passive oddball sequence preceded the two active blocks; (3) P300 amplitude was only affected by stimulus repetition in those subjects who performed more complex cognitive tasks between the first and second blocks and; (4) latency values were unaffected by repetition. It is hypothesised that the N1 amplitude decline may be caused by a decrease in alertness or arousal level produced by stimuli repetition. Reduction in P3 amplitude only appeared when more difficult tasks had to be done between the two oddball blocks and may reflect a decrease in the amount of attentional resources allocated to the second block, due either to fatigue or over training. The practice of using a grand average of several repetitions of the oddball paradigm, as recommended for the clinical use of long-latency ERPs, seems to be adequate provided that long interblock intervals are used and that the subject is not engaged in tasks requiring a high mental workload between the trial blocks.     

Electrophysiological evidence of facial inversion with rapid serial visual presentation

Using measurements of event-related potentials (ERPs) during a facial recognition task, we aimed to investigate the facial inversion effect and the role of time-based attention in processing upright and inverted faces. We presented upright and inverted faces at the T2 (target 2) position using a rapid serial visual presentation paradigm. Our results indicate that the N170 component shows the usual face inversion effect (FIE), in which inverted faces elicit larger N170 amplitudes and a longer elicit N170 latency. We also found that upright faces elicit larger P1 amplitudes than inverted faces over the left hemisphere. This study indicates that the N170 and P3, but not the P1, components are modulated by time-based attention. In addition, we found that the N170 amplitude was modulated by an attentional blink (AB) based on behavioral data. These results suggest that the disruption of facial configuration processing caused by inverted faces is relatively independent of attentional resources.     

Event-related potentials in autistic and healthy children on an auditory choice reaction time task

Event-related potentials (ERPs) were recorded from midline (Fz, Cz, Pz) and lateral sites (F3, F4, P3, P4) in autistic children (n = 7) and age-matched controls (n = 9) on an auditory choice reaction time task. Subjects were asked to press a button to an infrequent target (500 Hz, P = 0.14) and to ignore higher pitched infrequent (2000 Hz, P = 0.14) and frequent (1000 Hz) non-targets. Autistic subjects made twice as many errors of omission as controls and showed a higher criterion (beta) for targets. Maximum ERP peak amplitudes showed a more varied scalp distribution in the autistic group. N1 latencies were consistently shorter in the autistic group and in 3 subjects the target P3 latencies were markedly longer than for the controls. Compared to controls, the N1 amplitude of the autistic response was larger to the rare stimuli (particularly to non-targets). The amplitude of the P3 component was smaller in the autistic group (particularly to the target). The stimuli were also presented in a passive condition requiring no response. After subtraction of the waveform obtained in the passive condition from that obtained in the active condition or subtraction of the waveform elicited by the rare non-target from that elicited by the target, N1 target amplitude was larger in control than in autistic children. Autistic subjects showed more early negativity to the rare non-target at left frontal and a larger P3 to the target at right parietal sites. ERPs of autistic children are more responsive to stimulus features (e.g. high/rare non-target tone) and less responsive to their associations or meaningfulness (e.g. target P3). Attention-related ERPs of autistic children show signs of precocious (right dominance for P3) and delayed development (P3 not maximal at parietal sites).     

Auditory event-related potential abnormalities in bipolar disorder and schizophrenia.

Auditory P300 latency prolongation or amplitude reduction has been reported in patients affected by bipolar disorder and in schizophrenia. The purpose of this study was to test whether the auditory P300 and earlier event-related potential (ERP) components elicited during an auditory discrimination task could differentiate between these two disorders. Thirteen patients with manic or mixed bipolar disorder, 12 patients with schizophrenia, and 24 control subjects were evaluated. None of the subjects had a history of alcohol or substance abuse or dependence. ERPs were elicited during an auditory discrimination task in which a subject pressed a key to infrequent 1500 Hz tones interspersed amid a series of 1000 Hz tones. The amplitude and latency of N100 and P200 were measured from ERPs to non-target tones, and N200 and P300 were measured from ERPs to target tones. N100, P200 and N200 amplitudes were reduced in schizophrenia patients, but not in bipolar patients. Both bipolar disorder and schizophrenia patients showed reduced P300 amplitude and prolonged P300 latency. Amplitude reduction in the early ERP components implicates auditory processing deficits in schizophrenia. Both groups showed reductions in P300 amplitude, suggesting a disturbance of the temporal-parietal generators of this component. Prolonged P300 latency is consistent with impaired attentional processing in schizophrenia and symptomatic bipolar disorder patients.     

Auditory event-related potentials in attention and reading disabled boys

Event-related potentials (ERPs) were recorded from 4 groups of children: (1) reading disabled, (2) attentional deficit disorder with hyperactivity, (3) attentional deficit disorder without hyperactivity, and (4) normal controls. Subjects were instructed to press a button to a low probability tone (target, P = 0.168) and to ignore all other events which included a high probability tone (non-target, P = 0.664) and an unexpected novel sound (P = 0.168). The amplitude of several late ERP components and the latency of the P3b component were examined. As in a previously reported visual study with the same sample of children, the overall amplitude of the P3b component was significantly smaller in all the clinical groups than in controls. Two other late components (slow wave and Pc) were also smaller in the clinical groups than in controls. P3 latency did not, however, differentiate the groups.     

Early cognitive components of somatosensory event-related potentials

Somatosensory event-related potentials (ERPs) were recorded during a selective attention task involving electrical stimuli delivered to index fingers or the left and right median nerves at the wrist. In 11 healthy, young subjects, ERPs were recorded from 6 scalp locations while they mentally counted the electrical stimuli designated as target. Sequential ERP events measured included N20 (negativity at 20 ms), P30, P45, N60, P100, N140, P180, and P400. Analysis of amplitude data indicated modifications of both early and late ERP events with selective attention. While electrical stimulation at the wrist yielded early ERP amplitudes that were larger overall and latencies that were generally shorter, the selection attention effects did not differ on the basis of site of stimulation. The early ERP selective attention effects had differing scalp topography, with the P30/P45 effect of maximal over postcentral gyrus and N60 effect maximal over prerolandic gyrus. The data further elucidate the temporal features and spatial distribution of somatosensory ERP processes involved in attentional activity.     

Dissociation of visual C1 and P1 components as a function of attentional load: An event-related potential study

The earliest cortical location at which attention influences visual processing is controversial. To address this issue, the C1 and P1 components of cue-elicited ERPs were examined in a spatially-cued task under high and low levels of attentional load (active vs. passive viewing). Cues were presented either to the left or to the right visual field in separate trials (unilateral presentation), or to both visual fields simultaneously (bilateral presentation). For the unilateral presentation, C1 (peak latency approximately 80 ms) was not modulated by attentional load, whereas P1 (peak latency approximately 120-140 ms) was larger for high-relative to low-load condition. Bilateral presentation of the stimuli enhanced the amplitude of the C1 component relative to unilateral presentation; however, the increase of signal/noise ratio of C1 revealed no attentional load effect on C1. Results show that attentional load modulates visual processing in the P1, but not in the C1 time range, regardless of the increased signal/noise ratio by bilateral presentation. While it remains unclear about the conditions under which a C1 attentional effect is reliably elicited, the present results suggest that the direct manipulation of attentional load under a voluntary attention task seems not crucial for eliciting C1 attentional effect.     

Cognitive Event-Related Brain Potentials in Children with Attention and Reading Deficits

ERPs were recorded from four groups of children: reading disabled, attentional deficit disorder with and without hyperactivity, and normal controls. Subjects pressed a button to a low probability nonsense syllable (target, p= .168) and ignored all other events, which included a high probability nonsense syllable (nontarget, p= .664) and either low probability (category, p= .168) symbols (Block 1) or 3-letter words (Block 2). The amplitudes of several late ERP components and the latency of the P3 component were examined. The overall amplitude of P3 was significantly smaller in all clinical groups than in controls, but the difference in P3 amplitude between targets and nontargets was smaller only in the two attentional deficit groups. Reading disabled children had smaller P3 and Pc components to words than to symbols, while controls had equivalent values. The N2 component had a different scalp distribution for words and symbols, but did not differentiate reading disabled children from controls. P3 latency was significantly longer in the three clinical groups than in controls, but only the attentional deficit groups showed an increase in P3 latency across blocks of the task. The results are discussed within the framework of recent cognitive models dealing with attentional processes.     

Active attention modulates passive attention-related neural responses to sudden somatosensory input against a silent background

To reveal whether active attention modulates neuronal responses related to passive attention to somatosensory stimuli presented suddenly against a silent background, we examined the passive attention-related change in amplitude of the event-related brain potentials (ERPs), caused by temporal infrequency of stimuli. Eighteen healthy subjects performed passive and active attention tasks in two stimulus conditions. In the oddball condition, frequent (80%, standard) and infrequent (20%, deviant) electrical stimuli were randomly delivered to the second and third digits of the left hand. In the deviant-alone condition, the deviant stimulus (deviant-alone stimulus) was delivered with the same timing and sequence as in the oddball condition without standard stimuli. The P100, N140, and P200 elicited by the deviant-alone stimulus were enhanced in amplitude compared to those evoked by the oddball deviant stimulus in both the active and passive tasks. Moreover, active attention increased the enhancement of P100 and N140. The difference waveform (deviant-alone minus oddball deviant) provided similar findings. In conclusion, active attention enhances neural responses related to passive shifts of attention to somatosensory signals suddenly presented against a silent background. The results indicate that top-down signals for detecting target stimuli interact with passive shifts of attention caused by bottom-up signals.