几种不同认知事件下40Hz脑电事件相关电位的分维特性比较

我们研究了在汉字短时记忆—辨识测试、算术心算、汉字短时记忆容量测试等三种认知过程中，４０Ｈｚ脑电事件相关电位（４０ＨｚＥＲＰＳ）的分维特性．通过比较，发现在不同的认知过程中，４０ＨｚＥＲＰＳ的分维数明显不同，同时，在同一的认知过程中，４０ＨｚＥＲＰＳ分维特性也存在着显著的半球差异．这表明，由４０ＨｚＥＲＰＳ所表现的大脑动力学特性在左右半球之间及不同的认知过程中有较大的不同     

小波时频滤波器用于事件关联电位单次提取的研究

从单次脑诱发响应记录中提取有效信息，可以从根本上避免叠加平均法的弊端．在对听觉事件关联电位时－频域特性分析的基础上，结合相关分析方法，设计出了基于多分辨分析的样条小波时频滤波器，用以完成ＥＲＰ单次提取．大量提取实验表明，小波时频滤波器可以有效地从强背景噪声中提取单次ＥＲＰ．     

数字移动通信泛欧制式GSM中的语音编码研究

作者着重对泛欧数字移动通信系统（ＧＳＭ）规则脉冲激励长时预测（ＲＰＥ－ＬＴＰ）语音编码方案中的ＲＰＥ编码部分进行了研究。为了降低编码比特率，提出了一种每子帧１０个激励脉冲的新方案。对它进行了计算机模拟和性能分析，结果表明在１２ｋｂｉｔ／ｓ的编码率下，这种方案满足ＧＳＭ建议０６．１０，即对单个正弦波的帧信噪比要求。又用自适应差分脉冲编码调制（ＡＤＰＣＭ），代替ＲＰＥ－ＬＴＰ方案中的自适应脉冲编码调制     

铜,锌—四（4—三甲胺基苯基）卟啉的极谱研究

铜，锌与四（４－三甲胺基苯基）卟啉络合物极谱波均匀络合吸附波，峰电位分别为Ｅｐｃｕ＝－１．２２Ｖ（相对于ＳＣＥ），Ｅｐｚｎ＝－１．４７Ｖ，测定了络合比及条件稳定常数。     

慢性肾衰血浆中红细胞生成抑制蛋白的分离纯化

本文采用慢性肾功能衰竭（ＣＲＰ）病人血浆为材料，通过硫酸铵分步沉淀，ＤＥＡＥＤＥ－５２纤维素离子交换层析、ＳｅｐｈａｃｒｙｌＳ－１００凝胶层析及高效液相凝胶层析（ＨＰＬＣ），从中分离出一种蛋白质．经体外红系集落（ＣＷ－Ｅ）实验证明对ＣＦＵ－Ｅ有明显的抑制作用．该蛋白的分子量为５７０００，等电点（ＰＩ）为４．２，我们称这种蛋白为红细胞生长抑制蛋白（Ｅｔｙｔｈｒｏｒｏｉｅｓｉｓｉｎｈｉｔｏｒｒａｃｔｉｖｔｙｐｒｏｔｉｎ）．     

简易多用微型实验装置

简易多用微型实验装置邹荣贤（四川师范学院化学系，南充６３７００２）ＡＳＩＭＰＬＥＢＵＴＭＵＬＴＩ－ＰＵＲＰＯＳＥＭＩＮＩ－ＥＸＰＥＲＩＭＥＮＴＤＥＶＩＣＥ￥ＺｈｏｕＲｏｎｇｘｉａｎ（Ｄｅｐｔ．ｏｆＣｈｅｍｉｓｔｒｙ，ＳｉｃｈｕａｎＴｅａｃｈｅｒｓＣｉ...     

钴（Ⅱ）—氟哌酸络合物波的研究

氟哌酸（ＮＦＬＸ）在０．１ｍｏｌ·Ｌ＾－１ＮＨ３－ＮＨ４Ｃｌ（ｐＨ７．５）缓冲溶液中，与钴（Ⅱ）离子形成络合物，在单扫示波极谱仪上得一良好的络合物还原波，峰电位Ｅｐ＝－１．０９Ｖ（ｖｓ．ＳＣＥ），峰电流ｉｐ与钴（Ⅱ）浓度在０．０５０～２．５μｍｏｌ·Ｌ＾－１范围内成线性关系。用电化学手段研究了该体系的性质和反应机理，实验表明该波为不可逆吸附波。     

铜、锌－四（4－三甲胺基苯基）卟啉的极谱研究

铜、锌与四（４－三甲胺基苯基）卟啉络合物极谱波均为络合吸附波，峰电位分别为Ｅ＿（ｐＣｕ络）＝－１．２２Ｖ（相对于ＳＣＥ），Ｅ＿（ｐＺｎ络）＝－１．４７Ｖ．测定了络合比及条件稳定常数。     

铁－α－安息香肟的新吸附催化波

本文给出了铁－α－安息香肟络合物在Ｎａ２ＣＯ３－ＮａＨＣＯ３底液中的极谱吸附催化波．在该条件下，峰电位Ｅｐ＝－０．５８Ｖ（ｖｓ．ＳＣＥ）．铁在０～０．５μｇｍＬ－１范围内浓度和导数峰高呈线性关系．检测限为：５×１０－４μｇｍＬ－１．具有良好的稳定性和选择性．测定了头发及自来水中的痕量铁     

与选择性注意字符的细微结构相关的早内源性成分

在模拟人类自然阅读的方式下，研究了大脑对字符的细微结构进行选择性注意作业时的事件相关脑电位，获得了分布在Ｎ１位置及附近时域的与大脑认知过程直接相关的较早内源性成分，对Ｐ３００的心理学含义有了进一步的了解。     

An event-related potential study of working memory in children

Working memory refers to temporary storage and manipulation of “on-line” information in the brain,which is central to a large range of cognitive capabili- ties[1]. Visual working memory involves processes such as maintaining, updating and manipulating b…     

Early ERP effects on the scaling of spatial attention in visual search

This article describes the examination of the spatial‘scaling＇ effect of visual attention with the technique of event-related potential （ERP）. Eighteen participants were involved in a visual search task in which the cue-target paradigm was used. The search array was three concentric circles consisting of randomly selected English letters that were equally distributed in each circle. The behavioral and ERP data were recorded, respectively. The behavioral results showed that the response time increased and the response accuracy decreased with the increase of precue size. The ERPs amplitude of PI and NI components evoked by search array increased with the reduction of precue size. However, the latencies of these ERP components did not show significant differences between conditions. The hierarchical data of both behavioral assessment and ERPs provided evidence for the spatial ＇scaling＇ effect of visual attention. The amplitudes of PI and N 1 components may be used as indices to examine the effect of spatial ＇scaling＇. In different tasks, the display-set size of stimuli and the task complexity may be important factors that affect the attention allocation.     

脑损伤后综合征患者脑CT与事件相关电位的研究

探讨脑损伤后综合征患者的事件相关、脑CT和认知功能。应用听觉oddball序列刺激的事件相关电位方法对脑损伤后综合征患者30例（病人组）,健康人30例（对照组）进行比较。病人组较对照组P3潜伏期延长,波幅降低,经统计学处理有显著性差异（P＜0．05）。病人组脑CT检查有病灶者P3潜伏期延长,波幅降低更显著。事件相关电位检测和头频CT对研究损伤后综合征患者的认知功能变化有重要作用。     

Neural mechanisms of perceptual grouping in human visual cortex

The current work examined neural substrates of perceptual grouping in human visual cortex using event-related potential (ERP) recording. Stimulus arrays consisted of local elements that were either evenly spaced (uniform stimuli) or grouped into columns or rows by proximity or color similarity (grouping stimuli). High-density ERPs were recorded while subjects identified orientations of perceptual groups in stimulus arrays that were presented randomly in one of the four quadrants of the visual field.Both uniform and grouping stimulus arrays elicited an early ERP component (C1), which peaked at about 70ms after stimulus onset and changed its polarity as a function of stimulated elevations. Dipole modeling based on realistichead boundary-element models revealed generators of the C1 component in the calcarine cortex. The C1 was modulated by perceptual grouping of local elements based on proximity, and this grouping effect was stronger in the upper than in the lower visual field. The findings provide ERP evidence for the engagement of human primary visual cortex in the early stage of perceptual grouping.     

Brain dynamic mechanisms on the visual attention scale with Chinese characters cues

The temporal dynamics in brain evoked by the scale of visual attention with the cues of Chinese characters were studied by recording event-related potentials (ERPs). With the fixed orientation of visual attention, 14 healthy young participants performed a search task in which the search array was preceded by Chinese characters cues, “大, 中, 小” (large, medium, small). 128 channels scalp ERPs were recorded to study the role of visual attention scale played in the visual spatial attention. The results showed that there was no significant difference in the ERP components evoked by the three Chinese characters cues except the inferoposterior N2 latency. The targets evoked P2, N2 amplitudes and latency have significant differences with the different cues of large, middle and small, while P1 and N1 components had no significant difference. The results suggested that the processing of scale of visual attention was mainly concerned with P2, N2 components, while the P1, N1 components were mainly related with the processing of visual orientation information.     

睡眠剥夺影响大脑功能区状态的非线性评价

采用近似熵研究睡眠剥夺（sleep deprivation，SD）对脑认知功能的影响，评价SD引起的大脑功能区状态的非线性变化．12名受试者在正常睡眠和一夜SD之后分别接受视觉注意力测试，记录自发脑电和诱发脑电，采用二维插值构建19导脑电近似熵脑信息图（brain information map，BIM）．结果表明，在SD状态下，自发脑电的近似熵在全脑范围内有不同程度的下降，额叶处大脑偏侧性发生变化，复杂度的中心从左脑转移到右脑；前额叶处诱发脑电近似熵值降低，而顶叶和颞叶处则升高．脑电近似熵可以作为指标来评价SD对脑认知功能的负向影响，BIM的变化趋势与从生理学及影像学角度的分析相吻合，与线性方法的研究结论一致，在一定程度上可以反映大脑功能状态，提供一条评价脑功能区状态变化趋势的思路．     

儿童Stroop效应加工阶段特点的事件相关电位研究

选用小学六年级儿童为被试者,采用事件相关电位研究了Stroop效应的时间进程。实验中要求被试者判断在计算机屏幕中央出现的汉字颜色,并尽可能又快又准地按下相应的键,同时使用32导电极帽记录被试者的脑电信号。结果除了发现反应时的Stroop效应;还发现在汉字出现后大约300 ms左右,颜色与语义不一致的汉字诱发的P300比其它两种条件的波幅要大、潜伏期要晚;在汉字出现大约400 ms之后引发了一个慢波,不一致条件和控制条件引起的慢波波幅在头皮顶部比一致条件大。结果说明儿童Stroop效应的产生是一个复杂过程,干扰效应是早期颜色识别和后期反应选择两个阶段共同作用的结果,而促进效应则发生在后期的反应选择阶段。     

一种新的提取事件相关电位的退同步平均技术

指出了传统事件相关电位研究中的突现刺激会诱发外源性成分污染内源性认知成分 ,并导致注意自动俘获 .通过让符号串相对于视线移动来模拟自然阅读 ,发现了字符串中的串首和串尾符号会诱发出外源性成分 ,但串中的准持续呈现字符不会诱发外源性成分 .在此基础上 ,提出了一种去同步平均技术 ,利用该技术能够消除外源性成分干扰和注意的自动俘获 ,直接提取内源性认知成分     

ERP comparison of emotional activity between emotion-facilitation and emotion-interference children

A subliminal emotional Stroop experiment was carried out on 24 5-year-old children with event-related potential (ERP) recording. The children were separated into emotion-facilitation (EF) and emotion-interference (EI) groups based on their behavioral reaction times in emotional and neutral conditions. ERP result of these two groups showed different brain mechanisms of emotional related processing. When processing the emotional stimuli (negative or positive emotional facial pictures), the EI group activated more at the early stage of cognitive processing which was shown as an increase of P2 amplitude, while the lack of resources at the late stage of processing caused less activation which was shown as a decrease of N4 amplitude. The EF group had a reversed processing pattern as the EI group. For all groups of children, the left hemisphere was more sensitive to emotional processing. Furthermore, the positive and negative emotional information showed a similar pattern in the emotional and cognitive processing.     

ERP comparison of emotional activity between emotion-facilitation and emotion-interference children

A subliminal emotional Stroop experiment was carried out on 24 5-year-old children with event-related potential (ERP) recording. The children were separated into emotion-facilitation (EF) and emotion-interference (EI) groups based on their behavioral reaction times in emotional and neutral conditions. ERP result of these two groups showed different brain mechanisms of emotional related processing. When processing the emotional stimuli (negative or positive emotional facial pictures), the EI group activated more at the early stage of cognitive processing which was shown as an increase of P2 amplitude, while the lack of resources at the late stage of processing caused less activation which was shown as a decrease of N4 amplitude. The EF group had a reversed processing pattern as the EI group. For all groups of children, the left hemisphere was more sensitive to emotional processing. Furthermore, the positive and negative emotional information showed a similar pattern in the emotional and cognitive processing.