Neuropsychological performance and cognitive olfactory event-related brain potentials in young and elderly adults.

The P3 event-related brain potential (ERP) reflects neuroelectric activity related to the speed of cognitive processing and allocation of attentional resources. The objective of the present study was to assess the relationship between the P3 and Slow Wave components of the olfactory event-related potential (OERP) with neuropsychological performance in young (n = 16) and elderly (n = 16) adults. OERPs were recorded monopolarly from midline electrode sites while subjects estimated the odor magnitude of each stimulus, eliciting highly reproducible P3s. Results showed that the late cognitive components (P3 amplitude, P3 latency and Slow Wave area) decline with age and that this decreased neuronal efficiency is associated with reductions in the neuropsychological performance indexed by the Trail Making Test and the California Verbal Learning Test.     

Neuropsychological Performance and Cognitive Olfactory Event-Related Brain Potentials in Young and Elderly Adults

The P3 event-related brain potential (ERP) reflects neuroelectric activity related to the speed of cognitive processing and allocation of attentional resources. The objective of the present study was to assess the relationship between the P3 and Slow Wave components of the olfactory event-related potential (OERP) with neuropsychological performance in young (n = 16) and elderly (n = 16) adults. OERPs were recorded monopolarly from midline electrode sites while subjects estimated the odor magnitude of each stimulus, eliciting highly reproducible P3s. Results showed that the late cognitive components (P3 amplitude, P3 latency and Slow Wave area) decline with age and that this decreased neuronal efficiency is associated with reductions in the neuropsychological performance indexed by the Trail Making Test and the California Verbal Learning Test.     

Relationships between auditory event‐related potentials and mood state,medication, and comorbid psychiatric illness in patients with bipolar disorder

Background: Patients with bipolar disorder (BD) exhibit aberrations in auditory event‐related potentials (ERPs), although the relationships between these measures and mood state at testing, comorbid psychiatric illness, presence of psychotic features, and medication usage are unclear. The purpose of this study was to investigate the relationships between these factors and auditory ERP measures in BD patients. Methods: An auditory ‘oddball’ discrimination task was used to elicit ERPs from 69 patients with type I BD and 52 healthy controls. Patients were placed into subgroups based upon their mood state at testing (euthymic or symptomatic), and ANOVA was used to compare amplitude and peak latency measures from the N100, P200, N200, and P300 ERP components across subgroups. Multiple regression was used to investigate relationships between ERP measures and comorbid psychiatric diagnosis, history of psychotic features, and medication status. Results: Relative to healthy control participants, euthymic and symptomatic BD patients exhibited reduced P300 and P200 amplitude, but ERP measures did not differ among BD patients on the basis of mood status. A history of a comorbid anxiety disorder was associated with reduced N200 peak latency, but prolonged P300 peak latency among BD patients. No other relationships between clinical variables and ERP measures were significant. Conclusions: The results suggest that disrupted auditory attention may be observed in BD patients regardless of their mood state at testing, medication status, or history of psychosis. These results extend previous findings, and provide further evidence for aberrations in the P300 ERP as an endophenotype for BD.     

Electrophysiological correlates of personality dimensions measured by Temperament and Character Inventory

The present exploratory study was attempted to investigate the relationship between components of event-related potential (ERP) and Cloninger's personality dimensions. The ERP was measured using the auditory oddball paradigm, and personality was evaluated by Temperament and Character Inventory (TCI) in 25 healthy subjects. The results showed that P300 amplitude at Fz was significantly associated with reward dependence, and that P300 latency was positively correlated with persistence, and negatively correlated with novelty seeking. No correlations were found between N100, P200 and personality dimensions. These results indicate that personality dimension is related to information-processing in the brain. The neurobiological and psychological aspects of personality, which may relate to the P300 were considered.     

Latency of auditory P300 correlates with self-control as measured by the Sixteen Personality Factor Questionnaire

The reception, processing, and storage of information about experience define personality. The present study investigated the relationship between auditory event-related potentials (AERP) and personality traits. The AERP were recorded using a standard auditory oddball paradigm, and personality was evaluated by Cattell's Sixteen Personality Factor Questionnaire (16PF) in 20 healthy young male subjects. The P300 latency was found to be significantly associated with rule consciousness (factor G in the 16PF), perfectionism (factor Q3), and self-control (factor SC): it was negatively correlated with G score (r = -0.56, P = 0.01), Q3 score (r = -0.67, P = 0.001), and SC score (r = -0.65, P = 0.002). Moreover, the P300 amplitude and N100 amplitude were negatively correlated with reasoning (factor B; r = -0.46, P = 0.044; and r = -0.72, P = 0.002, respectively). These results indicate that the personality traits of self-control, perfectionism, high superego, and reasoning are related to information processing in the brain.     

The P3 auditory event-related brain potential indexes major personality traits.

BACKGROUND: The amplitude of the auditory P3 event-related potential is reduced in patients with axes I and II disorders. Data regarding P3 amplitude and normal personality traits in healthy individuals have been inconsistent, however, although more extreme variants of dimensional traits such as neuroticism and extraversion are associated with psychiatric morbidity. METHODS: Male subjects (n = 18) recruited from the community completed the NEO Five-Factor Inventory, which consists of five scales: Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness. P3 potentials were generated using an auditory discrimination paradigm to which a third, novel stimulus was added. Partial least squares analysis, a multivariate statistical procedure, was used to test the relationship, in both stimulus conditions, between P3 amplitude at six electrode sites and the five personality dimensions. RESULTS: P3 amplitude across conditions and sites was positively related to Extraversion, Openness, Agreeableness, and Conscientiousness and negatively related to Neuroticism. CONCLUSIONS: Previous studies have shown that both reduced P3 amplitude and a high Neuroticism/low Extraversion-Openness-Agreeableness-Conscientiousness trait pattern are associated with the presence of, and risk for, substantial psychiatric morbidity. Our results suggest that processes indexed by auditory P3 amplitude are related to these broad personality dimensions in healthy individuals.     

Frontal P300 Decrement and Executive Dysfunction in Adolescents with Conduct Problems

This study investigated the cognitive and cerebral function of adolescents with conduct problems by neuropsychological battery (STIM) and event-related potential (ERP). Eighteen adolescents with conduct disorder, and 18 age-matched normal subjects were included. Such cognitive functions as attention, memory, executive function and problem solving were evaluated using subtests of STIM. ERP was measured using an auditory oddball paradigm. The conduct group showed a significantly lower hit rate on the Wisconsin Card Sorting Test (WCST) than the control group. In addition, the conduct group showed reduced P300 amplitude at Fz and Cz, and prolonged P300 latency at Fz, and there was a significant correlation between P300 amplitude and Stroop test performance. These results indicate that adolescents with conduct problems have impairments of executive function and inhibition, and that these impairments are associated with frontal dysfunction.     

P300 and executive function alterations: possible links in a case of Morgagni-Stewart-Morel syndrome

To evaluate possible cause-effect relationships between hyperostosis frontalis interna and cognitive dysfunction, we performed a neurophysiological (event-related potentials, ERPs) and neuropsychological study in a case of Morgagni-Stewart-Morel (MSM) syndrome associated with frontal lobe compression. Neuropsychological evaluation evidenced selective impairment of executive function. Visual and auditory oddball ERPs revealed delayed P300 latency and reduced auditory P300 amplitude with multi-peaked morphology. ERP abnormalities and cognitive dysfunction could be due to the frontal bone-cortex conflict documented by neuroradiological investigations. Received: 15 July 2001 / Accepted in revised form: 23 January 2002     

额叶肿瘤患者认知功能和事件相关电位P300的研究

目的 探讨额叶肿瘤患者认知功能的损害和事件相关电位P300有关参数的变化特点,了解额叶在认知功能及P300产生中的作用.方法 对31例额叶肿瘤患者(左侧15例、右侧16例)及30例健康对照者分别进行Stroop字色干扰等多项认知神经心理学测试和P300检查.结果 与健康对照组相比,额叶肿瘤组认知功能各项测试指标评分均显著降低(P＜0.05),P300的N2、P3波潜伏期显著延长(P＜0.05),P3波幅显著降低(P＜0.05).进一步研究发现,右额叶肿瘤组患者的各项认知测试指标评分均显著低于健康对照组(P＜0.05),而左额叶肿瘤组只有词语流畅性指标评分显著低于健康对照组(P＜0.05);与健康对照组相比,左、右额叶肿瘤组P300的N2、P3波潜伏期均显著延长(P＜0.05),P3波幅均显著降低(P＜0.05);左、右额叶肿瘤组患者之间的P300比较则无统计学差异(p＞0.05).结论 额叶肿瘤患者认知功能有明显损害,右侧肿瘤患者的认知功能损害更严重:额叶可能与P300发生或传导有关,且左右额叶无明显的差异.     

Intellectual impairment and cognitive evoked potentials in myotonic dystrophy

Twenty-seven patients with myotonic dystrophy (MD) and 20 control subjects were tested using neuropsychological and electrophysiological measures. MD patients reported significantly lower scores on the Wechsler Adult Intelligence Scale and the Mini-Mental State Examination. P3 amplitude of auditory event-related potentials was significantly reduced in 14 patients. P3 latency was normal. In 13 patients, P3 was not elicited. Our results clearly show the presence of a significant impairment of cognitive functioning, as assessed by psychometric measures, in more than 50% of MD patients. Discriminant function correctly classified 92% of patients, using event-related potentials and neuropsychological variables.     

Relationships between event-related potentials and neuropsychological tests in neurologically healthy adults.

The aim of this study was to investigate the relationship between conventional neuropsychological tests and an event-related potential (P300). Subjects were 118 neurologically normal healthy adults 18-74 years old with no history of neurological, neurosurgical, or psychiatric disorders. We administered a neuropsychological test battery and recorded auditory P300 in all subjects. A significant correlation was seen between P300 latency and age, but not between amplitude and age. While significant negative correlations were apparent between some neuropsychological tests and age and P300 latency, stepwise regression analysis to assess the significance of each factor determined that age alone correlated with P300 latency. We therefore concluded that P300 measurements cannot be replaced by neuropsychological tests; rather, brain function should be evaluated by both methods.     

Neuropsychological test performance and MEG-based brain lateralization: Sex differences

Magnetoencephalographic (MEG) auditory evoked fields (EF) were recorded from left and right hemispheres of 9 normal males and 12 normal females. Source location of the 100 ms latency component (M100) was localized to superior temporal lobes bilaterally using an inverse solution algorithm. All subjects also were administered the Wechsler block design and visual reproduction subtests, and the California Verbal Learning Test (CVLT). M100 source locations demonstrated significant sex differences in interhemispheric asymmetry. Males had source locations further anterior than females, with the differences most pronounced in the right hemisphere. Expected sex differences were found in neuropsychological test performance, with males performing better on block design ad visual reproduction, and females performing better on the CVLT. Across both sexes, block design scores correlated significantly with right hemisphere M100 location, with more anterior source locations associated with better performance. CVLT scores were negatively correlated with right hemisphere M100 source locations. These findings suggest MEG-based measures of interhemispheric asymmetry may be related to specific neuropsychological test performance measures.     

Neuropsychological correlates of an attention-related negative component elicited in an auditory oddball paradigm in schizophrenia

An attention-related, negative component can be detected between the N100 peak and 200 ms after stimulus by subtracting event-related potentials (ERPs) elicited to background tones when subjects ignore tones, from ERPs elicited to background tones when subjects attend to tones to detect target tones in an oddball paradigm. To clarify the cognitive significance of this component in schizophrenia, we examined the correlations of 24 patients between the amplitude and latency of the negative component and results obtained using neuropsychological measurement methods, including the Wisconsin Card Sorting Test, the Trail Making Test, the Verbal Fluency Test and some subtests from the Wechsler Memory Scale. The latency prolongation of the negative component correlated positively with the difference in performance time between parts A and B of the Trail Making Test, which estimates set shift, a frontal-lobe executive function, but not with any other neuropsychological measurements, while the amplitude showed no such correlation. These results suggest that the latency prolongation of the attention-related, negative component induced in an auditory oddball paradigm may serve as an index for frontal dysfunction in schizophrenia.     

Clinical and neuropsychological correlates of the P300 in schizophrenia

We investigated the relationship between the P300, neuropsychological test performance and symptomatology in recent-onset schizophrenic patients (n = 45) to gain insight into underlying mechanisms of abnormal P300 in schizophrenia. The P300 was recorded in two sessions with an intermission of five minutes, at the midline frontal, central and parietal electrode site. P300 amplitude and latency were compared with those obtained in 25 controls. Twenty patients were treated with olanzapine and 19 patients with risperidone. P300 amplitude was smaller and latency longer in patients than in controls. In the patient group, parietal P300 amplitude reduction was related to poorer performance on neuropsychological tests of memory. Frontal P300 amplitude reduction was related to impaired selective attention. In patients with negative symptomatology, P300 amplitude was reduced in the second P300 session compared with the first. Patients on risperidone demonstrated a smaller parietal P300 amplitude than patients using olanzapine. Reduced parietal P300 amplitude could signify a dysfunction in the continuous memory updating of current events. Negative symptomatology may be associated with a time dependent decrease in neuronal firing, as indicated by reduced P300 amplitude in the second P300 session.     

Neuropsychological correlates of P300 abnormalities in patients with schizophrenia and obsessive-compulsive disorder

The cognitive significance of P300 abnormalities in schizophrenia and obsessive-compulsive disorder (OCD) was investigated. P300 was measured by an auditory oddball paradigm, in which a series of standard tones (1000 Hz) and target tones (1500 Hz) were presented. The subject's task was to count the number of the presented target tones. Cognitive functions were evaluated by neuropsychological tests, which were chosen to be sensitive to frontal and temporal dysfunction. Twenty-two schizophrenic patients, 19 OCD patients and 21 healthy controls participated. Event-related potentials measured at 15 electrode sites, which consisted of five levels on the left-right dimension and three levels on the anterior-posterior dimension, were included in the statistical analysis. P300 amplitudes on all 15 electrode sites were significantly smaller in schizophrenic and OCD patients than in the controls. Schizophrenic patients performed poorly on almost all neuropsychological tests, while OCD patients showed impaired performance on the Rey-Osterrieth Complex Figure Test and on a controlled oral word association test. In schizophrenic patients, P300 amplitude was associated with performance on verbal memory and learning by the Luria-Nebraska Neuropsychological Battery, while for OCD patients, P300 amplitude was related to the Trail Making Test, Part B response time. These results indicate that schizophrenic patients have generalized cognitive impairments, which are substrated by a wide range of cortical dysfunctions. The major cognitive deficits observed in OCD patients were impairments of controlled attention and self-guided, flexible behavior, which are mediated by the fronto-striatal system. The neurophysiological mechanisms underlying P300 abnormalities observed in schizophrenic and OCD patients are discussed.     

Attentional deficits in cocaine-dependent patients: converging behavioral and electrophysiological evidence

Although there are several reports of patients with cocaine dependence displaying cognitive deficits, the nature of their information processing deficits is not well characterized. In the present study, the attentional performance of cocaine-dependent patients (n=14) was examined and compared with that of healthy control individuals (n=15). Attention was assessed using an auditory oddball event-related task as well as the Continuous Performance Test (CPT, Identical Pairs version). The cocaine-dependent group displayed P300 amplitude reduction compared to controls. The group difference in P300 response latency did not reach significance. On the CPT, the cocaine-dependent patients displayed significantly poorer discriminability and greater errors of commission than the controls. There was a positive correlation between performance on the oddball event-related task and performance on the CPT. This investigation provides converging behavioral and electrophysiological evidence of attentional deficits in cocaine-dependent patients.     

Auditory P300 in borderline personality disorder and schizophrenia

Using three sets of clinical criteria to define borderline personality disorder (BPD), P300 (P3) and other long-latency auditory event-related electroencephalographic potentials were measured in 22 subjects with BPD, 32 subjects with other personality disorders, 29 schizophrenics, 22 depressives, and 74 volunteer controls. The patients with BPD were found to differ from patients with nonborderline personality disorders, having a longer P3 latency and smaller P3 amplitude. Long-latency event-related potentials were similar in the BPD and schizophrenic groups and did not differentiate patients with BPD with a concurrent diagnosis of schizotypal personality disorder from those without schizotypal personality disorder. The P3 latency and amplitude changes distinguished the BPD and schizophrenic groups from normal controls, those with major depressive disorder, and those with nonborderline personality disorders. These findings suggest that though some patients with BPD may have depressive symptomatology, they share with schizophrenics a dysfunction of auditory neurointegration.     

Deficits in auditory P50 inhibition in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is considered to involve abnormalities in inhibitory processes including gating systems. Auditory P50 inhibition, which is assessed by using a paired auditory stimulus paradigm to record P50 mid-latency evoked potential, is assumed to reflect sensory gating. In the present study, we investigated auditory P50 inhibition in subjects with OCD, and examined the relationship between P50 and clinical variables or neuropsychological performance. Twenty-six subjects with OCD and 26 age- and sex-matched healthy controls received P50 recording and neuropsychological tests. In the OCD subjects, we also evaluated clinical features including OC symptoms and subtypes of the disorder. P50 T/C ratios were significantly higher in OCD subjects than in control subjects (t=2.9, df=50, p=0.006). Compared to the controls, the OCD subjects performed significantly worse on the Symbol Digit Modalities Test (SDMT) and the Trail Making Test (TMT). There were no correlations between P50 T/C ratios and clinical variables or the results of neuropsychological tests. Our findings suggest that sensory gating deficits may be involved in the pathophysiology of OCD in a different way from clinical symptoms and executive attention dysfunction.     

Sensation seeking correlates of passive auditory P3 to a single stimulus

A single auditory stimulus in a passive ignore condition elicits a P3 potential (passive P3) that shares similar morphology with the classical P3 (P300 or P3b) in the active auditory 'oddball' paradigm. Since the classical P3 is correlated with introversion, anxiety, or sensation seeking, it was hypothesized that the passive P3 is correlated with sensation seeking personality. Therefore, 39 healthy subjects aged from 15 to 57 years and free from depression, were asked to answer Zuckerman's sensation seeking scales (SSS), and undergo an auditory event-related potential procedure with a single stimulus. In all subjects, a clear passive P3 appeared at three midline electrodes that shared similar latency and amplitude to the classical P3. The SSS total and experience seeking subscale scores were positively correlated with N1 amplitude at Fz. In contrast, the SSS total and some subscale scores were negatively correlated with the passive P3 amplitudes at the three electrodes. The sensation seeking personality effects on the passive P3 might be via a cortical inhibition process during memory updating, which are considered to be involved in the classical P3.     

Cognitive functions evaluated by P300 and visual and auditory number assays in children with childhood epilepsy with occipital paroxysms (CEOP).

PURPOSE: This study was planned to evaluate cognitive functions, especially attention and immediate recall, in children with childhood epilepsy with occipital paroxysms (CEOP), by using P300 and neuropsychological tests, which included visual and auditory number assays. Thirty patients with CEOP, ages ranging from 5 to 17 years were enrolled in the study. Twenty-five healthy children were taken as the control group. METHODS: Oddball paradigm was used in P300 recordings. The latency and the amplitude of the P300 wave recorded from Cz were taken into consideration. The neuropsychological test battery included visual and auditory number assays. RESULTS: P300 latency was significantly longer in the CEOP group (p=0.014). The results of the visual and auditory number assay test showed significant decline in the patient group when compared with the normal controls. CONCLUSIONS: Attention and immediate recall deficits as well as prolonged P300 latencies in children with CEOP can be due to an ongoing epileptic activity either influencing the whole brain or only the occipital lobe which can also be involved in the neuropsychological organization of the human cortex. Therefore, children with CEOP should be evaluated with more detailed neuropsychological tests for possible cognitive deficits.