大脑性瘫痪患者的体感诱发电位和运动诱发电位分析

目的；观察大脑性瘫痪（脑瘫，CP）患者体感诱发电位（SEP）和运动诱发电位（MEP）的表现。方法：对15例CP患者作四肢SEP和磁刺激MEP测试，并与对照组进行比较。结果：14例CP患者SEP中有3例异常，异常率21％，15例CP患者中MEP有14例异常，异常率93％，与临床表现相一致。结论：SEP和MEP可检测神经感觉和运动通路功能状况，对CP的诊断可提供客观依据。     

Analysis of sensory evoked potentials using normalised cross-correlation functions

Somatosensory evoked potentials (e.p.s) produced by stimulation of the dorsal columns were recorded from the cervicol medullary junction of adult rhesus monkeys, and were analysed using normalised cross-correlation functions (n.c.c.f.s.), simple peak detection and r.m.s. amplitude measurement. The n.c.c.f. provided measures of latency shift and waveshape change, while the more traditional peak-detection method provided measures of peak latency and peak amplitude. The results of these procedures were plotted as functions of time relative to a single, brief experimental manipulation (impact acceleration of the whole body). Analysis by means of the n.c.c.f. was found to be a versatile and effective technique the advantages of which include measurement of latency shifts with little contamination by moderate changes in waveshape, quantification of subtle waveshape changes and usefulness under a wide variety of noise conditions Opinions or conclusions contained in this report are those of the author and do not necessarily reflect the views or the endorsement of the Department of the Navy Reproduction in whole or in part is permitted for any purpose of the United States Government     

A study on the response selection and inhibition in a cognitive conflict task using event-related potentials

This study examined the hypothesis (Eriksen & Schultz, 1979) that a subject checks whether a prepared response is correct or not in the Eriksen and Eriksen (1974) cognitive conflict task, using event-related potentials (ERPs). Fourteen right-handed subjects were required to respond selectively to a central target letter flanked with compatible (e.g., HHHHHHH) or incompatible (e.g., SSSHSSS) noise letters, or not to respond to asterisks (*******). The results showed that the lateralized readiness potential indicating an incorrect preparation and the NO-GO potential reflecting a response inhibition emerged for incompatible stimuli. These findings indicate that a prepared response was recognized as erroneous, and was inhibited. Therefore, it is suggested that the check operation functioned in the cognitive conflict task. Furthermore, the result that the NO-GO potential latency for incompatible stimuli was longer than that for NO-GO stimuli suggests that the timing of NO-GO decision and response inhibition by the check operation influenced the NO-GO potential latency.     

脑血管病病人感觉障碍的体感诱发电位研究

目的：探讨脑血管病（ＣＶＤ）病人感觉障碍与体感诱发电位（ＳＥＰ）异常间的关系。方法：对ＣＶＤ２８例感觉障碍的病人，２１例只有运动障碍而无感觉障碍的病人和１０例正常人进行了ＳＥＰ研究。结果：感觉障碍组患侧中枢传导时间（ＣＣＴ）延长，与非患侧和正常对照组比较，差异均有显著性意义（Ｐ＜０．０５）。感觉障碍组Ｎ２０－Ｐ２５和Ｐ１５波幅比的异常率均明显高于无感觉障碍组。结论：ＣＶＤ的感觉障碍与ＳＥＰ的异常密切相关，ＳＥＰ可以做为判断ＣＶＤ时存在感觉障碍的客观指标     

Long-latency auditory evoked potentials in humans and the localization of a sound image

In the article, we discuss data from an investigation concerning how boundary conditions for the creation of sound-image movement are reflected in long-latency auditory evoked potentials and discuss how an important feature associated with the human localizing function (resistance to interference during the localization of both a stationary and a moving sound image) appears in long-latency auditory evoked potentials. We establish that a change in the parameters of a signal creating a sensation of sound-image movement results in an exhaltation of the amplitudes of the N₁ and P₂ components. The effect of binaural freedom from masking is reflected in these same components of long-latency auditory evoked potentials during movement of spatially shifting signals.Translated from Fiziologicheskii Zhurnal SSSR imeni I. M. Sechenova, Vol. 73, No. 2, pp. 260–268, February, 1987.     

Frontal negativity of pattern-reversal visual evoked potentials in humans.

We investigated the nature of negative potential in the frontal region with an approximate latency of 100 ms ('frontal negativity') as a component of pattern-reversal visual evoked potential (PVEP) in healthy human subjects. It was recorded by stimulation of one-half of the visual field, with different reference electrodes and with experimental manipulations of the stimulating visual field ('central scotomata' and 'peripheral constriction'). A negative potential field was demonstrated to be localized in the frontal region, and its physiological properties detected by the visual field manipulations were shown to be different from those of the occipital positive (P100) and negative (N105) components of PVEP. We conclude, therefore, that frontal negativity of PVEP is an actual electrical event generated in the frontal region, independent of P100 and N105.     

Objective detection of evoked potentials using a bootstrap technique

Evoked potentials are usually evaluated subjectively, by visual inspection, and considerable differences between interpretations can occur. Objective, automated methods are normally based on calculating one (or more) parameters from the data, but only some of these techniques can provide statistical significance (p-values) for the presence of a response. In this work, we propose a bootstrap technique to provide such p-values, which can be applied to a wide variety of parameters. The bootstrap method is based on randomly resampling (with replacement) the original data and gives an estimate of the probability that the response obtained is due to random variation in the data rather than a physiological response. The method is illustrated using auditory brainstem responses (ABRs) to detecting hearing thresholds. The flexibility of the approach is illustrated, showing how it can be used with different parameters, numbers of stimuli and with user-defined false-positive rates. The bootstrap method provides a new, simple and yet powerful means of detecting evoked potentials, which is very flexible and readily adapted to a wide variety of signal parameters.     

Phasic pupil dilation response to noxious stimulation in normal volunteers: relationship to brain evoked potentials and pain report

Pupillary response to noxious stimulation was investigated in men (n = 11) and women (n = 9). Subjects experienced repeated trials of noxious electrical fingertip stimulation at four intensities, ranging from faint to barely tolerable pain. Measures included pupil dilation response (PDR), pain report (PR), and brain evoked potentials (EPs). The PDR began at 0.33 s and peaked at 1.25 s after the stimulus. Multivariate mixed-effects analyses revealed that (a) the PDR increased significantly in peak amplitude as stimulus intensity increased, (b) EP peaks at 150 and 250 ms differed significantly in both amplitude and latency across stimulus intensity, and (c) PR increased significantly with increasing stimulus intensity. Men demonstrated a significantly greater EP peak amplitude and peak latency at 150 ms than did women. With sex and stimulus intensity effects partialled out, the EP peak latency at 150 ms significantly predicted PR, and EP peak amplitude at 150 ms significantly predicted the PDR peak amplitude.     

Visual and auditory evoked potentials in different areas of rat cerebral cortex

Visual and auditory evoked potentials were studied in the occipital, temporal, prefrontal and cingulate areas of the rat cerebral cortex. We found that both prefrontal and cingulate areas can respond to more than one sensory modality. The latencies of the response to light and sound, though slightly longer in these associative areas than in the two primary cortical regions, were still within the range of early sensory evoked responses (i.e. less than 50 ms).     

Scalp distribution of pattern visual evoked potentials in normal and hemianopic monkeys

We examined the hemispheric distribution of the pattern visual evoked potential in 3 Cynomolgus monkeys, before and after right optic tractotomy or left occipital lobectomy. The stimuli were vertical gratings of 4 spatial frequencies, presented using counterphase and on-off modulation at 1 and 8 Hz. In the normal monkey, the amplitude and latency of the PVEPs elicited by 1 Hz stimulation were similar across all electrode sites. While no differences were found in the phase of the PVEP elicited by 8 Hz stimulation across the different derivations, PVEP amplitude generally decreased over the lateral electrodes. Once experimental hemianopia was created, PVEPs recorded over the midline and the intact hemisphere were normal. However, partially polarity-inverted PVEPs of smaller amplitude were recorded over the deafferented hemisphere. In addition, the interhemispheric phase difference became more prominent in the PVEP recorded over the deafferented hemisphere as the spatial frequency was increased.     

Effect of differential rearing on photic evoked potentials and brightness discrimination in the albino rat

In two related experiments, albino rats were split into enriched and impoverished groups at weaning, and were reared for two months in differential environments, one group in a large cage containing toys, the other in individual cages. Photic evoked potentials were obtained from all subjects both at weaning and after differential rearing, and mean group latencies were compared. At the end of the experimental period, all subjects were tested on a black-white brightness discrimination. It was found that although the groups did not differ in evoked potential latency at weaning, after differential rearing there were significant latency differences. The enriched group developed shorter latencies than the impoverished group. At the end of the experiment, the enriched group obtained superior scores on a brightness discrimination test. It was concluded that differential rearing has measurable effects on certain aspects of the albino rat's behavior and physiology.     

Influence of mood on visually evoked potentials: a prospective longitudinal study.

Anecdotal observations have suggested that individual differences in mood state could be one reason for the variability of visually evoked potentials (VEP). Therefore, we designed a longitudinal study, in which VEP amplitude was measured and psychological dimensions were assessed. All subjects completed a 'mood state questionnaire' before each session. The results from the VEP measurement and from the mood questionnaire varied widely between subjects. The intraindividual reproducibility, however, was high in 15 of 20 subjects, even over 4 weeks. In some cases we found intraindividual variability of VEP amplitude to be highly correlated with some factors derived from the mood state questionnaire. An overall analysis of covariance and variance (ANCOVA) showed a significant negative correlation between VEP amplitude and the mood factor 'Tiredness' and a significant positive correlation between VEP amplitude and 'Activity'.     

糖尿病大鼠的脑干听觉诱发电位和中潜伏期反应

应用计算机平均叠加技术颅表记录大鼠脑干听觉诱发电位(BAEP)和中潜伏期反应(MLR),在链尿佐菌素(STZ)诱导的糖尿病大鼠连续70天同时动态观察BAEP和MLR的波峰潜伏期(PL)、波峰间潜伏期(IPL)及波幅的变化,旨在探讨糖尿病MLR和BAEP是否都有异常改变及同病程的关系。结果如下：糖尿病大鼠BAEP各波PL和I波-V波IPL在病程第28～42天出现持续性的明显延长,且均与病程呈正的直线相关关系;MLR各波PL和Pa波-Pb波IPL在病程第28～42天也出现持续性的明显延长,Na、Nb和Pb波PL也同病程呈正的直线相关关系。糖尿病大鼠BAEP各波波幅在病程第14～28天出现明显增大,MLR的Pa、Nb波波幅在病程第14天也出现明显增大。表明糖尿病大鼠BAEP和MLR有相似的异常改变并与病程有关。     

Event-related potentials in auditory backward recognition masking: A new way to study the neurophysiological basis of sensory memory in humans

Task-irrelevant pairs of short tones were presented to healthy human subjects while electric potentials were recorded from their scalp (‘event-related brain potential’, ERP). Infrequent increments in the frequency of the first tone of the repetitive tone-pair elicited an extra ERP component termed ‘mismatch negativity’ (MMN) when the silent interval between the first and second tone of the pair (‘inter-tone interval’) was long (150, 300, or 400 ms) but not when this interval was short (20 or 50 ms). This effect did not depend on whether the two tones of the tone-pair were presented to the same or to different ears. The present inter-tone interval effect is consistent with the effects of backward-masking on recognition performance in audition, suggesting that the MMN reflects the neurophysiological basis of echoic memory.     

Somatosensory event-related potentials in the rabbit cerebral and cerebellar cortices: a correspondence with mismatch responses in humans

Somatosensory event-related potentials (ERPs) were recorded from the cerebellar (CerCx), somatosensory (SomCx) and visual (VCx) cortices in rabbits in two stimulus conditions. In the oddball condition, airpuffs to two different locations in the rabbit's muzzle corresponded to infrequently presented deviant stimuli (oddball-deviants) interspersed with frequently presented standard stimuli. In the deviant-alone condition, deviants (alone-deviants) were presented without standards. ERPs to oddball-deviants differed significantly from those to standards in CerCx and SomCx, but not in VCx. Furthermore, some of these differences were not found between ERPs to alone-deviants and those to standards. Thus, ERPs to oddball-deviants contributing these differences were dependent on the presence of preceding standards. The results are in line with the elicitation of mismatch negativity-like ERPs to somatosensory changes in humans.     

Extraction of short-latency evoked potentials using a combination of wavelets and evolutionary algorithms

Somatosensory evoked potentials, recorded at the spine or scalp of a patient, are contaminated by noise. It is common practice to use ensemble averaging to remove the noise, which usually requires a large number of responses to produce one averaged signal. In this paper a post-processing technique is shown which uses a combination of wavelets and evolutionary algorithms to produce a representative waveform with fewer responses. The most suitable wavelets and a set of weights are selected by an evolutionary algorithm to form a filter bank, which enhances the extraction of evoked potentials from noisy recordings.