Visual P3-like potentials in squirrel monkey: Effects of a noradrenergic agonist

Event-related potentials (ERPs) were recorded from squirrel monkeys (Saimiri sciureus) in a 90-10 visual "oddball" paradigm. A small, blue rectangle was presented every 2 s on 90% of the trials (background), whereas a yellow rectangle occurred on 10% on the trials (oddball). Electrical activity time-locked to these stimulus events was recorded from epidural electrodes before and following systemic administration of the alpha-2 noradrenergic agonist clonidine (0.1 mg/kg intramuscularly, IM). Baseline data in response to oddball stimuli showed a large, P3-like potential exhibiting a fronto-central maximum along midline electrodes and a parietal maximum along lateral electrodes. A frontally dominant, long-latency, negative slow wave (SN) consistently followed this P3-like potential. Amplitudes for P3 were larger following 10% than 50% probable oddball events. These results suggest that monkeys exhibit large, probability-sensitive P3-like potentials similar to the visual potentials reported in humans. Administration of clonidine had no effect on the amplitude, area, or latency of the monkey P3 component. This contrasts with our previous findings that the same dose of clonidine significantly decreases auditory P3s in these monkeys. Such differences may reflect distinct functional roles for norepinephrine in the processing of low-probability acoustic versus visual signals and argues against the hypothesis that norepinephrine is a common neurotransmitter substrate for auditory and visual P3-like potentials.     

事件相关电位P300在轻度认知损害中的应用

轻度认知损害（Mild Cognitive Impairment,MCI）是阿尔茨海默病（Alzheimer Disease,AD）的前驱早期阶段,是介于AD和正常衰老之间的一种认知功能损害状态[1]。Petersen等认为MCI具有以下特征：（1）经常为忘事烦恼;（2）与受教育程度、年龄不相称的记忆损害;（3）保持一般的认知功能;（4）日常生活能自理;（5）没有痴呆。相关研究显示,MCI在老年人中的发生率为5．3％,每年有10％～15％的MCI患者转化为AD,而正常老年人群每年转化为AD仅为1％～2％。     

The impact of bilateral subthalamic deep brain stimulation on long-latency event-related potentials

The analysis of long-latency event-related potentials (ERPs) is of importance in the evaluation of certain cognitive functions and in following their subsequent changes. The aim of the present study was to investigate whether deep brain stimulation (DBS) itself can cause changes in the configuration of the ERPs. Using a standard oddball auditory paradigm, we elicited auditory cognitive ERPs in 23 Parkinson's disease patients (in both DBS-ON and DBS-OFF conditions) and in 14 healthy controls. The P200 and P300 amplitudes and latencies, the motor reaction times and the accuracy of button pressing were compared between the DBS-ON and DBS-OFF states and subsequently correlated with the applied stimulation voltage and disease duration. Comparison of the DBS-ON and DBS-OFF conditions revealed that neither the amplitude nor the latency of the examined ERP components changed significantly. However, the behavioral and attentional aspects (e.g. the accuracy of the button pressing responses to the target signal) definitely improved after the DBS was turned on. Positive correlations were demonstrated between the P300 amplitudes over the central and frontal regions and the optimal stimulation voltage and between the disease duration and P300 latencies over the Cz and Fz sites. In conclusion, our data indicate that DBS may have different impacts on various electrophysiological parameters during the oddball paradigm.     

Changes in auditory P300 event-related potentials and brainstem evoked potentials in diabetes mellitus

To investigate the influence of diabetes mellitus on higher cognitive functions electrophysiologically, we studied auditory P300 event-related potentials (P300) in 40 NIDDM patients, taking into account wave I-V latencies (I-V) in auditory brainstem evoked potentials, clinical parameters and head MRI findings. Compared with 20 controls, diabetics had significantly longer P300 and I-V latencies. P300 latencies in diabetics correlated with neither I-V. HbA₁, blood glucose levels, nor disease duration. Of the 13 diabetics investigated neuroradiologically, four had lacunar infarcts with prolonged electrophysiological values. The remaining nine had normal MRI scans, but their physiological parameters were still significantly longer than those of controls. These findings suggest that NIDDM can independently alter higher cognitive and the central auditory pathway functions. Our data also suggest that these alterations occur regardless of the recent metabolic derangement and disease duration. Cerebrovascular ischemia, if present, also appears to contribute in part to cognitive alterations.     

尼莫地平对Alzheimer病患者认知功能和听觉事件相关电位P300的影响

目的 观察尼莫地平对Alzheimer病(AD)患者认知功能和听觉事件相关电位P300的影响.方法 将65例AD患者随机分成两组,尼莫地平治疗组(尼莫地平组,32例):尼莫地平注射液治疗;吡拉西坦对照组(吡拉西坦组,33例):吡拉西坦注射液治疗.应用简易精神状态检查量表(MMSE)评定两组患者治疗前后认知功能状况,并进行治疗前后P300检查.同时记录药物不良反应.结果 两组各30例进入结果分析.治疗前两组MMSE评分、P300的潜伏期及波幅差异无显著性(均P＞0.05).治疗14 d、30 d时,两组MMSE评分显著提高(均P＜0.01),P300潜伏期均有缩短,波幅均有提高(尼莫地平组P＜0.01,吡拉西坦组P＜0.05);治疗90 d时,尼莫地平组MMSE评分显著提高、P300潜伏期显著缩短、波幅显著提高(均P＜0.01).治疗后14 d时认知功能改善尼莫地平组明显优于吡拉西坦组(总有效率分别为76.67%,70%)(P＜0.05).两组治疗期间无严重不良反应.结论 尼莫地平注射液能够改善AD患者的认知功能,比吡拉西坦更有效;这可能与尼莫地平的脑保护作用有关.     

抑郁症的事件相关脑电位P300实验研究

目的探讨抑郁症听觉事件相关电位P300的变化特点。方法对35例抑郁症患者和31名健康成年人,应用美国NieoletBravo脑诱发电位仪进行P300检测。结果与正常组相比,抑郁症组Oz点P3潜伏期延迟[正常组（315±29）ms,抑郁症组（341±31）ms,t=3．50,P〈0．01],P2潜伏期延迟[正常组（165±19）ms,抑郁症组（175±21）ms,t=2．02,P〈0．05],P3波幅降低[正常组（9．5±6．1）μV,抑郁症组（4．5±3．1）μV,t=4．27,P〈0．01],非靶P2波幅降低[正常组（4．2±1．2）μV,抑郁症组（2．3±1．3）μV,t=6．14,P〈0．01]。结论P300是评定抑郁症患者大脑综合功能的有效工具,在临床上值得进一步推广应用。     

酒依赖的事件相关电位P300实验研究

目的　事件相关电位P30 0是一种特殊的脑诱发电位。本研究探讨酒依赖患者事件相关电位P30 0的基本特征。方法　使用丹麦丹迪SEEG 16道技术系统 ,以及听觉靶—非靶刺激序列为诱发事件 ,检测 2 6例男性酒依赖患者 ,并与 31例正常男性进行比较。结果　与正常男性相比 ,酒依赖患者ERP/P30 0波形有变异 ,稳定性差。酒依赖患者P30 0靶和非靶主成分潜伏期延迟 ,波幅下降 (P <0 0 5或P <0 0 1)。结论　提示长期大量饮酒对脑功能有损害。P30 0若干指标或许可以作为酒依赖的检测手段。     

P300 of auditory event related potentials in occupational chronic solvent encephalopathy

This retrospective study characterized the P300 component of the auditory event related potential (ERP) and assessed its diagnostic value in occupational chronic solvent encephalopathy (CSE). The P300 was recorded on 86 CSE patients by the classical oddball paradigm. In addition to the laboratory's reference values, we used an age and education matched control group that consisted of 104 blue-collar workers with no known occupational solvent exposure. The association of P300 values with solvent exposure indices, major depression, alcohol consumption, and neuropsychological parameters was studied. The P300 amplitude was lower in CSE patients (mean 7.5 microV; S.D. 3.6) compared to laboratory controls (mean 11.8 microV; S.D. 4.1; F(1,167)=24.4; p<0.001, 95% CI -4.4 to -1.8) and to matched controls (mean 9.0 microV; S.D. 4.0; p=0.007, 95% CI -2.6 to -0.4). The P300 latency was longer in the CSE patients (mean 358 ms; S.D. 28) compared to laboratory controls (mean 339 ms; S.D. 19, F(1,167)=7.6, p=0.006, 95% CI 3.12-18.7) but did not differ from matched controls (mean 358 ms; S.D. 22; p=0.947, 95% CI -7.4 to 6.9). The solvent exposure indices, major depression, or alcohol consumption did not associate with the P300 values. The P300 amplitude correlated positively with the Digit Symbol test. All the amplitude values in the patient group and in the matched control group were classified as normal (i.e. age corrected mean+/-2.5S.D.) against the laboratory's reference values. Thirty percent of the latencies in the CSE patient group and 26% in the matched control group were classified as abnormal. At group level, the decreased P300 amplitudes in CSE patients may reflect solvent-related pathophysiology. However, the P300 measured with the classical oddball paradigm does not seem to be sensitive at individual level or useful in clinical practice.     

健康成人事件相关电位与神经心理学测验的相关性研究

目的 探讨事件相关电位P300的四个主要成分是否反映特定的认知功能。方法 将120名正常受试者按年龄分为三组，即20～34岁组、35～54岁组和55～70岁组，对所有受试者采用全套韦氏成人智力测验(WAIS-RC)等多项神经心理学测验以及P300进行测评，将神经心理学测验结果与P瑚结果进行Spearman等级相关分析。结果 三个年龄组中的N2潜伏期、P2波幅、N2波幅均与反映注意、短时记忆的神经心理学测验存在以下相关：在20～34岁组中，N2潜伏期与即刻视觉再生呈负相关(r=-0．352)，P2波幅与即刻视觉再生呈正相关(r=0．339)，N2波幅与即刻视觉再生呈正相关(r=0．331)。在35～54岁组中，N2潜伏期与数字广度、数字符号、词汇流畅均呈负相关(r分别=-0．357、-0．385、-0．316)；P2波幅与延线测验B呈负相关(r=-0．427)；Nl波幅与即刻逻辑记忆呈正相关(r=0．343)。在55～70岁组中，N2潜伏期与数字符号、词汇流畅呈负相关(r分别=-0．488和-0．321)，与延线测验B呈正相关(r=0．366)；P2波幅与数字符号呈正相关(r=0．314)；N2波幅与词汇流畅呈正相关(r=0．437)。在不同的年龄组中，P300的其他指标与神经心理学测验相关性不一致。结论 P300的四个主要成分可反映一定的认知功能，但不具有特异性，部分P300指标所反映的认知功能受年龄的影响。     

Evaluating sub-clinical cognitive dysfunction and event-related potentials (P300) in clinically isolated syndrome

Objective  This study investigated the presence of sub-clinical cognitive dysfunction in patients with clinically isolated syndrome (CIS) and the abnormalities of cognitive event-related potentials (ERPs). Methods  Subclinical cognitive dysfunction was assessed in 20 patients with CIS and in 20 healthy controls. Results  Patients had impairments in verbal learning and long-term memory, evaluating attention, executive function and visuospatial skills, in decreasing order of frequency. SDLT and SIT were the most, and COWAT and BNT were the least affected tests. The N200 and P200 latencies were prolonged, and N100, N200 and P200 amplitudes were reduced in the patients relative to the controls, from the Fz, Cz and Pz electrode positions (p<0.05). Conclusion  Detailed cognitive testing is valuable in determining subclinical cognitive dysfunction in CIS patients. ERP abnormalities as well as abnormalities in detailed cognitivetesting in patients with CIS are helpful in the diagnosis of sub-clinical cognitive dysfunction.     

Abnormalities of auditory event-related potentials in students with schizotypal personality disorder

Biological, phenomenological and cognitive similarities are known to exist between schizophrenia and schizotypal personality disorder (SPD). This study examined whether, and to what extent, abnormalities in event-related potentials (ERPs) already extensively reported in schizophrenia can also be observed in persons psychometrically identified with SPD. Event-related potentials were examined in nine SPD subjects and nine controls recruited from among 1693 college students, using the Schizotypal Personality Questionnaire (SPQ) and the Structured Clinical Interview for DSM-III-R (SCID I and II). Event-related potentials were recorded during an auditory oddball task. Smaller P300 amplitude and prolonged P300 latency were found in SPD subjects as compared with controls. Our findings indicate that such individuals do have deficits in information processing similar to that found in schizophrenia. We can conclude that P300 abnormalities may not be specific for SPD but that abnormalities shown in SPD are possibly a vulnerability marker for developing schizophrenia.     

橄榄体脑桥小脑萎缩听觉P300认知电位的研究

目的 观察P300检查在橄榄体脑桥小脑萎缩中的应用价值及影响因素.方法 应用P300检查和认知能力筛选量表(CASI)对34例橄榄体脑桥小脑萎缩患者和与其年龄、性别相匹配的正常对照组进行检测.结果 患者不同年龄组P300潜伏期较对照组明显延长(t=2.682～4.983,P<0.05～0.01),患者不同年龄组CASI评分比正常对照组明显降低(t=2.486～5.241,P<0.01),患者组P300潜伏期与CASI评分之间呈负相关(r=-0.48,P<0.005),病情轻组[(348.68±21.47) ms]与重组[(363.27±30.15) ms]和脑萎缩明显组[(354.46±26.98) ms]与不明显组[(338.74±23.56) ms]之间P300潜伏期均差异有显著意义 (P<0.01).结论 评价橄榄体脑桥小脑萎缩的认知功能状态,P300检查是一项有价值的客观指标,其异常程度与病情轻、重和脑萎缩程度有关.     

Auditory event-related potentials in panic disorder

To investigate the psychophysiological features of panic disorder (PD), we recorded auditory event-related potentials (ERPs) in 12 patients with PD meeting the DSM-IV criteria and in 12 age-matched normal controls. The ERPs were recorded during a standard two-tone discrimination task (oddball task). The probabilities of the rare target (1200 Hz) and frequent non-target tones (1000 Hz) were 15 and 85%, respectively. The subjects were required to press a button in response to the rare target tones. Scalp electroencephalograms were recorded from Fz, Cz, Pz, C3, and C4. The State-Trait Anxiety Inventory and Manifest Anxiety Scale scores were assessed for clinical evaluation. Analysis of variance revealed that the N1 and N2 amplitudes for target tones and the N1 amplitude for non-target tones were significantly larger in the PD patients than those in the controls. The two groups did not differ significantly in P3 latency and amplitude. The larger N1 and N2 amplitudes in the PD patients are suggestive of alteration of early information processing in PD.     

Conflict monitoring and stimulus categorization processes involved in the prosocial attitude implicit association test: Evidence from event-related potentials

The implicit association test (IAT) is a promising method used to assess individual implicit attitudes by indirectly measuring the strengths of associations between target and attribute categories. To date, the cognitive processes involved in the prosocial attitude IAT task have received little attention. The present study examined the temporal dynamics of the IAT that measures prosocial attitude using event-related potentials (ERPs). ERP results revealed enhanced N2 amplitudes for incongruent trials when compared with congruent trials and enhanced P300 amplitudes for congruent trials when compared with incongruent trials. In addition, the N2 amplitude differences were significantly correlated with individual prosocial behavior (the amount of donation). Our findings suggest that conflict monitoring and stimulus categorization processes are involved in the prosocial attitude IAT task and that the ERP indices of IATs that measure prosocial attitude may predict individual prosocial behavior.     

Association between waking electroencephalography and cognitive event-related potentials in patients with obstructive sleep apnea

ObjectiveSleepiness, cognitive deficits, abnormal event-related potentials (ERP), and slowing of the waking electroencephalography (EEG) activity have been reported in patients with obstructive sleep apnea (OSA). Our study aimed at evaluating if an association exists between the severity of ERP abnormalities and EEG slowing to better understand cerebral dysfunctions in OSA.MethodsTwelve OSA patients and 12 age-matched controls underwent an overnight polysomnographic recording, an EEG recording of 10 min of wakefulness, and an auditory ERP protocol known to specifically recruit attention. P300 and P3a ERP components were measured as well as the spectral power in each frequency band of the waking EEG. Pearson product moment correlations were used to measure associations between ERP characteristics and EEG spectral power in OSA patients and control subjects.ResultsA positive correlation between the late P300 amplitude and θ power in the occipital region was observed in OSA subjects (P < .01). A positive correlation was also found between P3a amplitude and β1 power in central region in OSA subjects (P < .01). No correlation was observed for control subjects.ConclusionsERP abnormalities observed in an attention task are associated with a slowing of the waking EEG recorded at rest in OSA.     

长期住院男性精神分裂症患者的认知功能与事件相关电位P300的相关性

目的 探讨长期住院的男性精神分裂症患者认知功能的变化与事件相关电位P300的关系.方法入组长期住院男性精神分裂症患者82例和健康对照52人.采用美国Nicolet Viking Quste诱发电位仪记录事件相关电位P300的潜伏期和波幅.采用动物命名测验、范畴流畅性测验、数字划消测验、连线测验(TMT-A、TMT-B)、Stroop测验(单词、颜色、色词干扰测验)、木块图测验、WMS-Ⅲ空间广度测验评估认知功能.结果患者组各项认知功能测验成绩与对照组之间差异均有统计学意义(P<0.01).患者组事件相关电位P300潜伏期较对照组明显延长(t=22.990,P<0.01),波幅较对照组明显降低(t=-9.699,P<0.01).患者组事件相关电位P300潜伏期与数字划消测验及TMT-A呈正相关(r=0.481,P<0.01;r=0.245,P<0.05).事件相关电位P300波幅与数字划消测验呈负相关(r=-0.338,P<0.01).结论长期住院男性精神分裂症患者虽处于稳定期,但仍存在认知功能的损害.事件相关电位P300的潜伏期和波幅可能是精神分裂症认知功能的电生理指标,并与患者的认知量表评估结果之间存在相关性.     

Confirmation of a relationship between reduced auditory P300 amplitude and thought disorder in schizophrenia

We have previously reported an association between reduced amplitude of auditory P300 event-related potential and severity of positive thought disorder as assessed by the Comprehensive Index of Positive Thought Disorder in a sample of patients with chronic schizophrenia. Here we replicate those findings using a different measure, Thought Disorder Index (TDI), in a new larger sample of 55 patients. The auditory P300 amplitude showed a significant negative correlation with scores on TDI. This correlation was relatively more pronounced in the left temporal region than in the right temporal region. These results further suggest that electrophysiological abnormalities of information processing may underlie positive thought disorder in schizophrenia.     

Subsequent memory effects on event-related potentials in associative fear learning

Studies of human fear learning suggest that a reliable discrimination between safe and threatening stimuli is important for survival and mental health. In the current study, we applied the subsequent memory paradigm in order to identify neurophysiological correlates of successful threat and safety learning. We recorded event-related potentials, while participants incidentally learned associations between multiple neutral faces and an aversive outcome [unconditioned stimulus (US)/conditioned stimulus (CS)+] or no outcome (noUS/CS−). We found that an enhanced late positive potential (LPP) to both CS+ and CS− during learning predicted subsequent memory. A quadratic relationship between LPP and confidence in memory indicates a possible role in both correct and false fear memory. Importantly, the P300 to the omission of the US (following CS−) was enhanced for remembered CS−, while there was a positive correlation between P300 amplitude to both US occurrence and omission and individual memory performance. A following re-exposure phase indicated that memory was indeed related to subjective fear of the CS+/CS−. These results highlight the importance of cognitive resource allocation to both threat and safety for the acquisition of fear and suggest a potential role of the P300 to US omission as an electrophysiological marker of successful safety learning.     

Early and late auditory event-related potentials in cognitively high functioning male adolescents with autism spectrum disorder

Event-related potentials (ERP) studies have offered diverging results in characterizing the basic nature of abnormal sensory processing and discrimination in autism spectrum disorders (ASDs). In the present study we report duration mismatch negativity (MMN) and later ERP components (P3a and P3b) derived from auditory odd-ball paradigms in a homogenous sample of cognitively high functioning male adolescents with ASD. We find significantly reduced frontal and temporal MMN amplitudes and no differences in P3a or P3b amplitudes or latencies compared to controls. These findings are in contrast to recent studies reporting enhanced ERP amplitudes to auditory stimuli, and are more in support of a weakened automatic auditory sensory processing as being central to the abnormal auditory behavioral responses commonly encountered in ASD.     

P300 auditory event-related potentials and neuropsychological study during donepezil treatment in vascular dementia

Abstract After Alzheimer’s disease (AD), vascular dementia (VaD) is the most common cause of dementia among the elderly. Abnormalities in neurotransmitter pathways are common pathogenic mechanisms shared by AD and VaD. For one month we studied the effects of donepezil, an acetylcholinesterase inhibitor (5 mg daily), on the cognitive system using P300 auditory event-related potentials (P300) and neuropsychological tests in 10 patients affected by probable VaD according to the NINDS-AIREN criteria. Our data showed a significant improvement of neuropsychological items and P300 latency after one month of donepezil treatment. In conclusion both P300 and neuropsychological tests are indicated in patients with VaD to confirm the efficacy of donepezil treatment during follow-up.