Forensic Study on Objective Evaluation of Visual Acuity of Ametropia with the Event-related Potential P3

Objective In this study,we aimed to assess the characteristics of the P3 component from an event-related potential(ERP)that was induced by visual acuity(VA)processing.Furthermore,we sought to provide electrophysiological evidence for the objective evaluation of VA.Methods We recruited 32 participants with myopia-related ametropia.They reported no other ocular diseases and had an uncorrected VA of 4.0 in both eyes.We used the block letter“E”at different visual angles and orientations as the graphic stimuli.The oddball paradigm,consisting of 4 modules,was used for ERP analysis.The standard stimuli of each module were identical,with a visual angle of 1°15′.The visual angles of the target stimuli were 1°15′,55′,24′,and 15′.The VA test was performed on each eye separately for all participants,and all characteristics of the P3 component were analyzed.Results There was no significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 55′group,or between the target stimulation angle 24′group and the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 1°15′group and the 24′group as well as the 15′group.There was a significant difference in the P3 peak letencies between the target stimulation angle 55′group and the 24′group as well as the 15′group.No significant differences were observed in the P3 amplitude between modules.Conclusion In the oddball paradigm,P3 elicitation indicated a cognitive response to the target stimuli.These data showed that the characteristics of P3 can be used as an objective evaluation of VA.

Correlation of cognitive function with acetylcholinesterase activity and P300 event-related potential of patients with type 2 diabetes mellitus

BACKGROUND： At present, central cholinergic neuron system is regarded the most major structural basis of cognitive function. Changes in structure of cholinergic neuron system of brain and receptor expression after brain injury can cause cognitive impairment. OBJECTIVE＂ To comparatively observe the intelligence quotient （IQ）, latent period and wave amplitude of P300 event-related potential and the difference of activity of acetylcholinesterase （ACHE） in blood and cerebrospinal fluid between patients with type 2 diabetes mellitus and with non-diabetes mellitus, and analyze the correlation of IQ of cognitive impairment patients with diabetes mellitus with AChE activity, latent period and wave amplitude of P300 event-related potential in cerebrospinal fluid. DESIGN： Correlation analysis of contrast observation SETTING： Department of Endocrinology, Affiliated Hospital of Binzhou Medical College PARTICIPANTS： Totally 32 patients with type 2 diabetes mellitus who received the treatment in the Department of Endocrinology, Affiliated Hospital of Binzhou Medical College between April 2004 and April 2005 were recruited, serving as diabetes mellitus group. They, including 19 male and 13 female, aged 49 to 73 years, with disease course of 4 to 11 years, all met the diagnostic criteria of diabetes mellitus revised by World Health Organization in 1999. Another 30 patients with non-diabetes mellitus who homeochronously underwent lumbar anesthesia in the Department of Surgery and Department of Gynecology were recruited, serving as non-diabetes mellitus group. The 30 patients included 18 male and 12 female, and their age ranged from 46 to 71 years. Informed consents of detected items were obtained from the involved patients. METHODS： ① Evaluation,on IQ： The IQ of involved subjects was evaluated with Chinese Version of the Wechsler Adult Intelligence Scale revised by Gong Yao-xian （WAIS-RC）. WAIS-RC included 6 verbal subscales and 5 performance subscales. The test scores of the 11 subscales integrated into the scores of the whole scale, and the scores on the WAIS-RC included verbal IQ （VlQ）, performance IQ （PIQ） and full scale IQ （FIQ）. FIQ ≤79 scores indicated low IQ and FIQ≤69 indicated intelligence impairment. ② Detection of P300 wave： P300 wave was detected with evoked potential instrument （MYTOPRO, Italian）, and data of latent period and amplitude of P300 event-related potential were automatically shown by computer. ③ Detection of AChE activity in blood and cerebrospinal fluid： Activity of AChE of blood and cerebrospinal fluid was measured with biochemical methods by using CORNING-560 autoanalyzer.④Correlation analysis： Correlation of FIQ with AChE of cerebrospinal fluid and P300 wave of patients with type 2 diabetes mellitus was analyzed, t test was used in intergroup comparison and linear correlation analysis for relevant treatment. MAIN OUTCOME MEASURES： ① Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups. ② Analysis on the correlation of FIQ of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave. RESULTS： Thirty-two patients with diabetes mellitus and 30 non-diabetes mellitus participated in the result analysis. ①Comparison of IQ, latent period and wave amplitude of P300 wave as well as the activity of AChE between two groups： The scores of VIP, PIQ and FIQ of patients with type 2 diabetes mellitus were （97.4±10.4）. （92.6±8.4） and （95.2±9.7） scores, respectively; and those of patients with non-diabetes mellitus were （104.7±9.6）, （102.5±8.5）and（102.7±8.9） scores, respectively, and P 〈 0.05-0.01 was set in intergroup comparison. The latent period of P300 wave at points Fz , Cz and Pz of patients with type 2 diabetes mellitus was （370.8±41.8）.（371.5±39.1）and （375.1±43.1） ms, respectively, and that of patients with non-diabetes mellitus was （ 332.1 ±28.3 ）, （335.7 ±29.4）and （339.7 ±27.3） ms, respectively, and P 〈 0.01 was set in intergroup comparison; Wave amplitude of P300 of patients with type 2 diabetes mellitus was （8.6±4.1）,（8.6±4.0） and （7.7±4.0） μV, respectively and that of patients with non-diabetes mellitus was （11.9±4.1）,（11.5±4.4） and （10.9±5.0） μV, respectively , and P 〈 0.05-0.01 was set in intergroup comparison; The level of AChE in blood and cerebrospinal fluid of patients with type 2 diabetes mellitus was （235.61 ±50.34）and （17.89±4.46） μkat/L, respectively, which was significantly higher than that of patients with non-diabetes mellitus [（205.03±44.15）and （14.63±0.48） μkat /L, respectively], and P 〈 0.05-0.01 was set in the intergroup comparison. ② Correlation of FIQ value of patients with type 2 diabetes mellitus with AChE of cerebrospinal fluid and P300 wave： The value of FIQ was significantly negatively correlated with the AChE activity of cerebrospinal fluid （r=-0.588 1, P 〈 0.01 ）, significantly negatively correlated with the latent period at points Fz. C and Pz of P300 wave （r= -0.700 5, -0.689 4, -0.688 5, P 〈 0.01 ）, and significantly positively correlated with the amplitude at points Fz . Cz and Pz of P300 wave（r= 0.607 4,0.616 1,0.592 0,P 〈 0.01 ）. CONCLUSION： ① Cognitive impairment of patients with type 2 diabetes mellitus might be related to the increase of activity of AChE in cerebrospinal fluid. ②Combined application of examination of P300 wave and evaluation of IQ is more useful in deciding the state of cognitive function of patients with type 2 diabetes mellitus.

Differential cognitive responses to guqin music and piano music in Chinese subjects： an event-related potential study

Objective To compare the cognitive effects of guqin （the oldest Chinese instrument） music and piano music. Methods Behavioral and event-related potential （ERP） data in a standard two-stimulus auditory oddball task were recorded and analyzed. Results This study replicated the previous results of culture-familiar music effect on Chinese subjects： the greater P300 amplitude in frontal areas in a culture-familiar music environment. At the same time, the difference between guqin music and piano music was observed in NI and later positive complex （LPC： including P300 and P500）： a relatively higher participation of right anterior-temporal areas in Chinese subjects. Conclusion The results suggest that the special features of ERP responses to guqin music are the outcome of Chinese tonal language environments given the similarity between Guqin＇s tones and Mandarin lexical tones.

Effect of variable number of tandem repeats polymorphism in the human dopamine transporter gene on conflict information processing according to event-related potential

The dopamine transporter （DAT） is responsible for dopamine reuptake from the synaptic cleft. A variable number of tandem repeats polymorphism in the DAT gene is related to DAT availability and has been associated with cognition. With the advantage of high-time resolution, event-related potential is an important method to study the time course of human information processing. Previous results have suggested that dopamine exhibits a close relationship with conflicting information processing. Therefore, the present study assumed that conflicting information processing could be influenced by DAT variable number of tandem repeats polymorphism. To confirm this, the present study analyzed the influence of DAT genotypes on N270, which is presumed to reflect neural activity of conflict information processing in young healthy adults. A S1-S2 matching task was performed in healthy adults with 10/10 genotype （n = 14） and 10/9 genotypes （n = 14）, respectively, when event-related potentials were recorded. Results demonstrated that subjects with the 10/10 genotype exhibited shorter N270 latency and quicker reaction times compared with subjects with the 10/9 genotype. There were no differences in N270 amplitude between the two genotypes. These results suggested that 10/10 genotype subjects more efficiently processed conflict information.

Relationships among Event-Related Potentials, Memory, and Schizophrenic Symptoms in College Students with Schizotypal-Traits

The present study investigated the relationships among event-related potentials (ERPs), memory, and schizophrenic symptoms in college students with schizotypal-traits. Scores on the Schizotypal Personality Questionnaire (SPQ) were used to categorize the participants into schizotypal-trait (n = 30) and normal control (n = 37) groups. ERPs were assessed using an auditory oddball paradigm, in which a series of standard tones (1000 Hz) and target tones (1500 Hz) were presented;participants were asked to count the number of presented target tones. The verbal memory and visual memory of the participants were evaluated using the Korean version of the California Verbal Learning Test (K-CVLT) and the Rey-Osterrieth Complex Figure Test (RCFT), respectively. The schizotypal-trait and control groups did not differ in terms of age, educational level, IQ score, accuracy on the auditory oddball task, or performance on the K-CVLT and RCFT measures. However, the schizotypal-trait group exhibited significantly smaller P300 amplitudes than the control group. Additionally, the P300 amplitudes measured at Cz and Pz were negatively correlated with the cognitive-perceptual factor scores on the SPQ. Thus, the present results indicate that reduced P300 amplitudes may represent a biological marker of schizophrenia.

THE EFFECT OF ELECTROACUPUNCTURE ON AUDITORY P300 POTENTIAL IN MONGOLISM CASES

In treating children with mongolism(Down’s syndrome)with electroacupuncture,thelatent period of P3 is shortened,which shows that the cerebral reaction to externalstimulus in classification,encoding and recognition is accelerated.Along with the elevatedP3 amplitude,the cerebrum is more capable of processing the external information,showing improvement of the mental state.

精神分裂症患者事件相关电位P300及其与发病次数的关系

目的探讨首发与复发精神分裂症患者的电生理机制差异。方法对28例精神分裂症首次发作患者(首发组)、32例复发精神分裂症患者(复发组)进行事件相关电位P300的测定,测量其错误数和反应时,潜伏期和波幅,并与30名健康志愿者的结果进行比较。结果①患者组的反应时显著长于对照组(t=8.25,P<0.05);正确率差异无统计学意义;②与对照组相比,患者组在C3、C4电极处,潜伏期均显著延迟(t=2.47,2.56;P<0.05);Fz、Cz、C3、C4点波幅均显著降低(t=3.12,4.14,4.27,3.08;P<0.05);③与首发组相比,复发组在C3、C4、Fz点的潜伏期显著延迟(t=2.58,3.07,6.78;P<0.05);C3、C4、Fz、Cz点波幅均显著降低(t=5.13,4.55,8.35,4.70;P<0.05)。结论首发、复发精神分裂症患者认知功能均受损,且复发患者受损程度大于首发患者。提示患者认知功能受损是一个累积下降的过程。

精神分裂症患者血清同型半胱氨酸水平与P300的相关

目的探讨精神分裂症患者血清同型半胱氨酸水平(Hcy)与事件相关电位P300的关系。方法随机将年龄在18~65岁之间符合CCMD-3精神分裂症诊断标准患者45例作为试验组,选择45例健康者作为对照组。同时采用酶联免疫法检测血清Hcy水平及以P300评定认知功能,并将结果加以分析、比较。结果与对照组相比,研究组CZ、PZ点N1、P2、N2、P3潜伏期均明显延长(t=2.36~3.86,P<0.05或0.01),研究组CZ、PZ点N2、P3波幅明显降低(t=3.06~5.27,P<0.01);研究组血清Hcy水平高于对照组(t=2.76,P<0.01);CZ、PZ点P300潜伏期与血清Hcy水平呈正相关(r=0.36~0.49,P<0.05或0.01),CZ、PZ点P300波幅与血清Hcy水平则呈负相关(r=-0.47^-0.51,P<0.01)。结论精神分裂症患者血清Hcy水平升高,其认知功能损害可能与血清Hcy代谢异常有关。

P300评估抑郁症的病程与认知功能障碍的相关性

目的 采用事件相关电位P300的改变来研究抑郁症患者的病程与认知功能障碍的相关性.方法 对40～ 50岁年龄段的115例抑郁症患者,以病程＞2年为标准分为两组进行事件相关电位研究.结果 ＞2年抑郁症患者组P300潜伏期较＜2年组延长（U=3.15,P＜0.05）,P300波幅较＜2年组降低（U=4.79,P＜0.001）.结论 抑郁症患者的病程越长、认知功能损害程度越严重.

Combined Effects of Electroacupuncture and Behavioral Training on Learning-Memory Ability and Event-Related Potential P300 in Rats with Mid/Advanced Cerebral Infarction

Background： The effectiveness of the combination of electroacupuncture （EA） and behavioral training （BT） for mid/advanced cerebral infarction （M/ACI） and related mechanisms remains unclear. This study aimed to investigate the combined effects on the learning-memory ability and event-related potential P300 in rats with M/ACI. Methods： Eighty rats with M/ACI were divided into Group Model （M）, Group EA, Group BT, and Group EA-BT （n = 20） according to the random number with five healthy rats in Group Control （CON）. On the 6th week after modeling, EA, BT, and EA-BT were given to Group EA, Group BT, and Group EA-BT, respectively, whereas Group M and Group CON were not given any intervention. Y-maze test and P300 were recorded before and after the intervention. Results： After intervention, the P300 latency was lower and the amplitude was higher in the Group EA-BT, Group EA, and Group BT than before （for latency, t = -7.638, -4.334, and -5.916; for amplitude, t = 8.125, 3.846, and 5.238; P 〈 0.01 ）, with Group EA-BT superior to Group EA （for latency, t = -3.708; for amplitude, t = 3.653; P 〈 0.01） and Group BT （for latency, t = -2.067; for amplitude, t = 2.816; P 〈 0.05）, with no significant difference between Group BT and EA （for latency, t = -1.439; for amplitude, t = 1.075; P 〉 0.05）. While the performances of Y-maze tests in the Group EA-BT, Group EA, and Group BT were all better than before （t = 10.359, 4.520, and 7.791, P 〈 0.01）, with Group EA-BT better than Group EA （t = 5.627, P 〈 0.01 ） and Group BT （t = 2.913, P 〈 0.01 ） respectively, and Group BT better than Group EA （t = 2.912, P 〈 0.01）. Conclusion： EA or BT can affect P300 in rats with M/ACI, and the combination of these two methods can significantly improve the learning-memory ability.

Connecting the P300 to the diagnosis and prognosis of unconscious patients

The residual consciousness of unconscious patients can be detected by studying the P300, a wave among event-related potentials. Previous studies have applied tones, the subject＇s name and other names as stimuli. However, the results were not satisfactory. In this study, we changed the constituent order of subjects＇ two-character names to create derived names. The subject＇s derived names, together with tones and their own names, were used as auditory stimuli in event-related potential experiments. Healthy controls and unconscious patients were included in this study and made to listen to these auditory stimuli. In the two paradigms, a sine tone followed by the subject＇s own name and the subject＇s derived name followed by the subject＇s own name were used as standard and deviant stimuli, respectively. The results showed that all healthy controls had the P300 using both paradigms, and that the P300 in the second paradigm had a longer latency and two peaks. All minimally conscious state patients had the P300 in the first paradigm and the majority of them had the P300 in the second paradigm. Most vegetative state patients had no P300. Patients who showed the P300 in the two paradigms had more residual consciousness, and patients with the two-peak P300 had a higher probability of awakening within a short time. Our experimental findings suggest that the P300 event-related potential could reflect the conscious state of unconscious patients.

P300 change and cognitive behavioral therapy in subjects with Internet addiction disorder A 3-month follow-up study

Event-related potential studies of cognitive function in addiction behaviors have focused on the P300 event-related potential component. The current study investigated the association between P300 component and Internet addiction disorder. We found that individuals with Internet addiction disorder exhibited significantly longer P300 latencies than controls （N2： P = 0.035; P3a： P = 0.031 P3b： P = 0.043） and similar P300 amplitudes compared to control participants. After 3 months of cognitive behavioral therapy, P300 latencies decreased significantly in the P3a and P3b （P3a： P = 0.045; P3b： P = 0.062）. These results suggest that deficits in cognitive function may be involved in Internet addiction disorder, and that clinical psychological treatment may be effective.

Automatically detecting auditory P300 in several trials

A method was demonstrated based on Infomax independent component analysis(Infomax ICA) for automatically extracting auditory P300 signals within several trials. A signaling equilibrium algorithm was proposed to enhance the effectiveness of the Infomax ICA decomposition. After the mixed signal was decomposed by Infomax ICA, the independent component(IC) used in auditory P300 reconstruction was automatically chosen by using the standard deviation of the fixed temporal pattern. And the result of auditory P300 was reconstructed using the selected ICs. The experimental results show that the auditory P300 can be detected automatically within five trials. The Pearson correlation coefficient between the standard signal and the signal detected using the proposed method is significantly greater than that between the standard signal and the signal detected using the average method within five trials. The wave pattern result obtained using the proposed algorithm is better and more similar to the standard signal than that obtained by the average method for the same number of trials. Therefore, the proposed method can automatically detect the effective auditory P300 within several trials.

Progress in the application of P300 in depression

Depression is a common mental disor-der with low mood,loss of interest and pleasure as main symptoms.Because of depending on the subjective diag-nosis of psychiatrists,its diagnosis is no reliable objective basis.P300 research findings can be used as an objective diagnostic indicator for patients.This paper mainly intro-duces the current research status of event-related poten-tials for depression and introduces the scientific research and clinical significance of P300 for depression.

A Hybrid Brain-Computer Interface for Closed-Loop Position Control of a Robot Arm

Brain-Computer interfacing(BCI)has currently added a new dimension in assistive robotics.Existing braincomputer interfaces designed for position control applications suffer from two fundamental limitations.First,most of the existing schemes employ open-loop control,and thus are unable to track positional errors,resulting in failures in taking necessary online corrective actions.There are examples of a few works dealing with closed-loop electroencephalography(EEG)-based position control.These existing closed-loop brain-induced position control schemes employ a fixed order link selection rule,which often creates a bottleneck preventing time-efficient control.Second,the existing brain-induced position controllers are designed to generate a position response like a traditional firstorder system,resulting in a large steady-state error.This paper overcomes the above two limitations by keeping provisions for steady-state visual evoked potential(SSVEP)induced linkselection in an arbitrary order as required for efficient control and generating a second-order response of the position-control system with gradually diminishing overshoots/undershoots to reduce steady-state errors.Other than the above,the third innovation is to utilize motor imagery and P300 signals to design the hybrid brain-computer interfacing system for the said application with gradually diminishing error-margin using speed reversal at the zero-crossings of positional errors.Experiments undertaken reveal that the steady-state error is reduced to 0.2%.The paper also provides a thorough analysis of the stability of the closed-loop system performance using the Root Locus technique.

Clinical Study on Treatment of Senile Vascular Dementia by Acupuncture

63 patients with senile vascular dementia were randomly divided into the treatment group (treated by acupuncture) and the control group (treated with piracetam). The authors observed the changes in the score of Hasegawa's dementia scale (HDS), p300, rheoencephalogram, topographic EEG, superoxide dismutase (SOD) activity in erythrocytes, and lipid peroxide (LPO) level in plasma before and after treatment. The statistical data showed that the total effective rate in the treatment group (80.6%) was significantly higher than that in the control group (25%), and the differences in the observed indexes before and after treatment were significant (P 0.05), indicating that the acupuncture treatment was superior in immediate therapeutic effect on senile vascular dementia to drug treatment.

Auditory ERP Differences in the Perception of Anticipated Speech Sequences in 5 - 6 Years Old Children and Adults

The perception of complex auditory information such as complete speech sequences develops during human ontogeny. In order to explore age differences in the auditory perception of predictable speech sequences we compared event-related potentials (ERPs) recorded in 5- to 6-year-old children (N = 15) and adults (N = 15) in response to anticipated speech sequences as successive and reverse digital series with randomly omitted digits. The ERPs obtained from the omitted digits significantly differed in the amplitude and latency of the N200 and P300 components between adults and children, the N400 and LPC components were more pronounced in children in the right frontal area for the digits presentation. These findings indicate that the perception of a successive speech structure is less automated in children and requires a detailed analysis of the successive structure and error detection. These differences in auditory ERPs reflect developmental changes in the auditory perception of speech sequences and can serve as indicators of the maturity of cognitive functions in children.

Visuo-motor related time analysis using electroencephalograms

The objective of the present study was to assess the relationship of response time and peak latency of P300 with a simple-reaction task. Seven male subjects who were experienced players in decision-making sports were included. Two main findings were noted. First, the P300 latencies of Fz and Pz were correlated with visuo-motor related time. Second, in terms of latencies of visual evoked potentials, the correlations were observed only between Oz-P2 latency and visuo-motor related time. These results suggest that the length of visuo-motor related time is related to the processing involved in the higher order brain site involving specific processing in the visual cortex.

女性抑郁症首次发病患者认知事件相关电位P300与脑灰质体积的相关分析

目的 探讨首次发病未服药女性抑郁症患者脑灰质体积变化特点,以及与认知事件相关电位P300的相关分析.方法 对25例18 ～58岁首次发病未服药女性抑郁症患者（患者组）和28名健康对照者（对照组）行头部3D结构MRI扫描,并对患者组进行P300检查.结果 患者组较对照组右侧额下回岛盖部、右侧中央前回灰质体积减小.患者组中P3、N2潜伏期均与双侧壳核、右侧颞中回体积呈正相关（均P ＜0.01）;P3潜伏期与左侧颞中回、左侧额中回、左侧梭状回体积呈正相关（均P＜0.01）,而P3波幅与左侧角回、右侧额上回体积呈负相关（均P＜0.01）;N2潜伏期与左侧后扣带回、右侧梭状回、枕叶、左侧小脑体积呈正相关（均P＜0.01）;患者组P300潜伏期和波幅与汉密尔顿抑郁量表的总分和各因子分无相关性.结论 首次发病未服药女性抑郁症患者存在特征性脑灰质体积异常,其P300可能与多个脑灰质区域相关,尤其与颞叶、基底神经节的关系最明显.

药物滥用性头痛患者认知功能及事件相关电位P300的研究

目的探讨药物滥用性头痛(MOH)患者认知功能及认知电位的变化情况。方法MOH患者(观察组)及对照组各30例,两组均进行P300、简易精神状态量表(MMSE)检测。采用SPSS 10.0软件进行数据处理,P300潜伏期、波幅比较采用t检验。结果两组P300靶刺激中P3潜伏期、波幅比较均差异有统计学意义:观察组P3潜伏期[分别为(393.70±42.60)ms]较对照组[(331.05±22.35)ms]延长,差异有统计学意义(t=7.13,P<0.05);观察组P3波幅[(3.40±2.30)u V]较对照组[(6.20±2.40)u V]明显降低,差异也有统计学意义(t=4.59,P<0.05)。两组MMSE评分比较,观察组总分、定向力、记忆力、计算力、回忆力、语言能力[(24.00±2.21)分,(8.15±0.86)分,(2.88±0.23)分,(3.07±1.04)分,(1.72±0.89)分,(8.42±1.33)分]低于对照组[分别为(27.07±2.06)分,(9.28±1.03)分,(3.01±0.26)分,(3.25±1.20)分,(1.92±0.90)分,(9.69±1.44)分],总分、定向力、语言能力评分差异有统计学意义(t=3.66,3.19,3.34;P<0.05)。结论 MOH患者存在轻度的认知功能障碍,认知电位P300为MOH患者认知功能障碍的诊断提供一客观指标。