Evoked potential correlates of auditory signal detection

A long-latency comnponent of the averaged evoked potential recorded from the human scalp varied in close relationship with subjects' perceptual reports in an auditory signal detection task. Detected signals evoked potentials several times larger than did undetected signals, falsely reported signals, or correctly reported nonsignals. The threshold signal intensity at which detection perfornmance exceeded chance levels was identical with concurrently obtained electro-physiological measures of threshold.     

动态脑电图联合脑干听觉诱发电位在脑卒中患者预后评估中的应用价值

目的：探讨动态脑电图联合脑干听觉诱发电位在脑卒中患者预后评估中的应用价值.方法选取脑卒中患者152例,随机分为观察组和对照组,每组各76例.观察组患者选用动态脑电图结合脑干听觉诱发电位进行监测,对照组患者选用常规脑电图进行监测,对比两组患者预后评估结果和预后评估中价值.结果观察组患者中真阴性和真阳性的例数均明显多于对照组,差异具有统计学意义（P〈0.05）;观察组患者中假阴性和假阳性的人数均明显少于对照组,差异具有统计学意义（P〈0.05）.观察组患者检测的敏感性、特异性、错误率均明显高于对照组,准确率明显低于对照组,差异具有统计学意义（P〈0.05）.结论动态脑电图联合脑干听觉诱发电位能够有效增加脑卒中患者预后评估的特异性和敏感性,提高评估的准确率,值得在临床治疗中推广使用.     

Electrical signs of selective attention in the human brain

Auditory evoked potentials were recorded from the vertex of subjects who listened selectively to a series of tone pips in one ear and ignored concurrent tone pips in the other ear. The negative component of the evoked potential peaking at 80 to 110 milliseconds was substantially larger for the attended tones. This negative component indexed a stimulus set mode of selective attention toward the tone pips in one ear. A late positive component peaking at 250 to 400 milliseconds reflected the response set established to recognize infrequent, higher pitched tone pips in the attended series.     

Operant control of eye movements during human vigilance

Eye movements were used as a criterion of observing responses in a vigilance task. Time on watch and signal rates similarly affected both eye-movement rates and percentage of detections. Observing rate may account for detection data, and may be a more stable measure of vigilance than detection rate is, especially when very few signals occur.     

Operant controlled neural event: formal and systematic approach to electrical coding of behavior in brain

Traditional studies of electrophysiological correlates of behavior contain inherent high variability resulting from the arbitrary choice of behaviors, brain locations, and wave parameters. The operant control of neural events is a formal and systematic approach to the study of prespecified parameters and components of brain activity as they encode behaviors. Two studies in which the electrical activity of brain was the criterion for reinforcement demonstrate the acquisition, under such operant control, of two mutually exclusive behaviors or states which selectively alter evoked potential components.     

Operant control of neural events in humans

Human subjects were trained by traditional methods of instrumental conditioning to change the amplitude of a late component of the auditory evoked potential with and without oscilloscopic feedback of their performance.     

基于碰撞声信号的农产品品级检测技术综述

基于碰撞声信号的农产品品级检测技术,凭借其灵敏度高、快捷、无损、环保等优点,已成为国内外学者关注和研究的热点。为了廓清该检测技术中信号处理方法的研究进展,特从时频分析、主成分分析、数据挖掘、独立分量分析、小波分析5个碰撞声信号处理的角度,详细介绍了农产品碰撞声信号处理的方法、过程及结论,综述了近十几年国内外利用碰撞声检测技术对农产品进行检测与分级的研究成果及发展趋势,并指出了碰撞声检测技术进一步研究的方向。     

在线社会网络多维度链式信任计算算法

针对在线社会网络中用户间的复杂关联和信任问题,本文提出一种链式优化方法来降低用户关联的复杂性,同时结合多维度用户评价、时间衰减、共谋识别以及目标用户信誉值几方面综合计算目标用户的动态信任值,建立了在线社会网络优化及信任计算算法,有效地解决了在线社会网络的信任计算问题.     

Tobacco and evoked potential

Significant changes were found in two indices of the averaged visual evoked potentials in nine smokers after 12 and 36 hours of abstinence and after resumption of smoking. There was a decrease of the amplitude envelope accompanying withdrawal and an increase with resumption of smoking. These changes are consistent with the contention that tobacco increases arousal. Amplitude changes were found in a specific component of the evoked potential occurring between 100 and 125 milliseconds after the onset of the flash. The latter changes suggest the possibility that smoking selectively enhances the perceptiont of weak stimuli.     

Evoked response correlate of symbol and significate

Changing the source and intensity of the auditory signal to six trained cats responding to meaningful auditory stimuli permits exogenous and endogenous processes in the auditory evoked potential to be separated. For short-latency exogenous processes, latency and amplitude depend on the parameters of the physical stimulus. However, the amplitude and shape of longer-latency endogenous processes are essentially independent of the location and intensity of the signal source and seem to be invariant concomitants of the significance of the signal.     

Attention-related increases in cortical responsivity dissociated from the contingent negative variation

Certain tasks which increase attention to stimuli also elicit the contingent negative variation and increase the amplitude of the P300 component of the sensory evoked response. Therefore it appeared possible that the contingent negative variation and attention-related increases in P300 are either confounded by artifact or generated by common neural mechanisms. The fact that we have recorded attention-related increases in P300 amplitude independent of corresponding systematic changes in contingent negative variation indicates that neither of these possibilities is correct. The two phenomena are independently variable modulations of cortical activity.     

一种流动体泄漏自动检测新方法

流动体泄漏自动检测系统是基于通信传输理论，根据流动体泄漏的特点，提出了一种全新的泄漏检测方法。该方法采用在流动体发送端加入测试物质或测试信号，在接收端检测该物质或信号，依据其变化确定是否有泄漏。     

Averaged evoked responses in vigilance and discrimination: a reassessment

With the use of monopolar recordings for averaged evoked responses, detected signals in a vigilance task are associated with a late positive component which is absent for undetected signals as well as nonsignals. Bipolar recordings obscure the late positive component associated with detected signals. The data suggest that the late positive component represents cerebral processes associated with evaluation of unpredictable changes in stimulation.     

基于等价空间残差的线性模拟电路故障检测

在模拟电路的故障检测中,为了克服模拟元件的参数容差的影响,降低信号测量难度,便于嵌入式测试的实现,提出了一种基于等价空间残差的故障检测方法.该方法使用键合图模型建立电路的状态方程,通过观测矩阵的正交空间投影消去状态变量,使故障指示残差仅与输入信号和观测信号有关.电路仿真实验结果表明该方法在元件存在容差的情况下可以有效的利用电压测量信号实现线性模拟电路的故障检测,具有测量实现简单,抗干扰能力强的优点,适合模拟电路的嵌入式测试.     

Grueneberg ganglion cells mediate alarm pheromone detection in mice

Alarm pheromones (APs) are widely used throughout the plant and animal kingdoms. Species such as fish, insects, and mammals signal danger to conspecifics by releasing volatile alarm molecules. Thus far, neither the chemicals, their bodily source, nor the sensory system involved in their detection have been isolated or identified in mammals. We found that APs are recognized by the Grueneberg ganglion (GG), a recently discovered olfactory subsystem. We showed with electron microscopy that GG neurons bear primary cilia, with cell bodies ensheathed by glial cells. APs evoked calcium responses in GG neurons in vitro and induced freezing behavior in vivo, which completely disappeared when the GG degenerated after axotomy. We conclude that mice detect APs through the activation of olfactory GG neurons.     

昌黎生态监控区无机N、P 变化及潜在性富营养化评价

对2006—2010年每年8月河北昌黎生态监控区测定的无机N(NO2-N、NO3-N、NH4-N)和无机P(PO4-P)含量,进行多年站位及总量分析,揭示其年际变化趋势,并结合海水质量标准进行潜在性富营养化评价。结果表明:无机N总量(DIN)于前4年持续下降,而2010年急剧上升至历年最高水平,其中NO3-N含量总体水平远高于NO2-N和NH4-N,成为DIN主要组成部分;无机P含量则呈波动性上升趋势。潜在性富营养化评价结果显示,2010年19个站位均为P限制潜在性富营养(ⅥP),其他年份仅个别站位呈N或P限制潜在性富营养(ⅤN或ⅥP)及中度营养(Ⅱ),其余均为贫营养(Ⅰ)。     

New Islanding Detection Method with Better Performance in Presence of Non-resistive Load

Islanding detection is a mandatory component in grid-connected photovoltaic(PV) inverters. It is also a key issue in the photovoltaic agriculture. In this work, an overview on the islanding effect in grid-connected PV power systems was provided. Various islanding detection methods were introduced and their strength and weakness were dicussed. An improved islanding detection method was proposed based on active frequency drift(AFD). The new method tolerated capacitive and inductive loads, because its perturbation signal was not offset by the non-resistive load. The new method through simulation in MATLAB/Simulink was evaluated and the advantages of the new method were demonstrated.     

Alteration of plasma proteins at metamorphosis in the lamprey (Petromyzon marinus dosatus)

Coincident with metamorphosis in the lamprey (Petromyzon marinus dosatus), a new, more rapidly moving plasma protein component appears. In the mature lamprey this new component is of major quantitative importance. With paper electrophoretic mobility as the sole criterion, the new component is considered to be an alpha globulin rather than albumin.     

管道防腐层大修案例分析及大修选段原则

通过案例分析并结合现场经验,制定了管道防腐层大修选段的系列原则,即管道防腐层外观的完整与否并不能作为防腐层技术状况的判定依据。在回填土壤的应力作用下,管道在3∶00~9∶00时钟位置的石油沥青防腐层容易出现剥离并屏蔽阴极保护,导致管体腐蚀。中等精度的漏磁检测器所给出的管道内检测结果作为管道防腐层选段大修的依据具有较高的置信度。     

Evoked potential correlates of signal recognition between and within modalities

Electrical responses evoked by clicks, flashes, changes in noise level, and changes in light level were recorded from the scalps of human subjects set to detect one of the stimuli. An early negative component of the evoked responses reflects selection between sensory modalities, whereas the later positive component reflects a more complex intramodal discrimination.