Use of running fractal dimension for the analysis of changing patterns in electroencephalograms

Running fractal dimensions were measured on four channels of an electroencephalogram (EEG) recorded from a normal volunteer. The changes in the background activity due to eye closure were clearly differentiated by the fractal method. The compressed spectral array (CSA) and the running fractal dimensions of the EEG showed corresponding changes with respect to change in the background activity. The fractal method was also successful in detecting low amplitude spikes and the changes in the patterns in the EEG. The effects of different window lengths and shifts on the running fractal dimension have also been studied. The utility of fractal method for EEG data compression is highlighted.

Multi-channel signal separation

The separation of independent sources from mixed observed data is a fundamental and challenging problem. In many practical situations, observations may be modelled as linear mixtures of a number of source signals, i.e. a linear multi-input multi-output system. A typical example is speech recordings made in an acoustic environment in the presence of background noise and/or competing speakers. Other examples include EEG signals, passive sonar applications and cross-talk in data communications. In this paper, we propose iterative algorithms to solve the n × n linear time invariant system under two different constraints. Some existing solutions for 2 × 2 systems are reviewed and compared.

A detailed investigation of classification methods for vowel speech imagery recognition

Accurate and fast decoding of speech imagery from electroencephalographic (EEG) data could serve as a basis for a new generation of brain computer interfaces (BCIs), more portable and easier to use. However, decoding of speech imagery from EEG is a hard problem due to many factors. In this paper we focus on the analysis of the classification step of speech imagery decoding for a three-class vowel speech imagery recognition problem. We empirically show that different classification subtasks may require different classifiers for accurately decoding and obtain a classification accuracy that improves the best results previously published. We further investigate the relationship between the classifiers and different sets of features selected by the common spatial patterns method. Our results indicate that further improvement on BCIs based on speech imagery could be achieved by carefully selecting an appropriate combination of classifiers for the subtasks involved.

Zum tierschutzgerechten Betäuben und Töten von Aal

Slaughtering of eels should be done not only under animal welfare aspects but as well under consumer protection and economical aspects with respect to technical feasibility. Methods must be practicable for enterprises slaughtering quantities of several kilograms up to several tons per day. Most methods applied up to now in whole Europe were (are) not in accordance with animal welfare mainly due to lacking prescriptions and alternative methods. The great number of experiments carried out within the frame of this project demonstrates the difficulties to combine optimal welfare demands with economical and technical fesibility aspects in one method. Measurements of EEG (electroencephalogram) and ECG (electrocardiogram) have shown that the method laid down in the german legislation does not perfectly stun all eels. This method was improved by applying a „prestun“ with 220 V for 1sec., followed by a 5 min phase at 45 V to prolongue the time of unconsciousness after the stun. Inflating nitrogen gas into the stunning bath additionally causes asphyxia during the stun. By this method 93% of the eels were stunned or even killed. Applying 220 V for bigger batches of eels (~400 kg) will cause big problems with the energy supply. Therefore this method is restricted to batches of 20 - 50 kg. The method laid down in the german legislation probably can be improved. Eels were stunned successfully without water, avoiding the problems of regional differences in the conductivity of the water. Other types of current and other frequencies and a combination of both should be tested as well as alternative electrode geometries also with respect to blood spots which occasionally occurred in the muscles preferably of bigger eels (>800 g). For the time being the method laid down in the german legislation is a reasonable compromise and under animal welfare aspects represents a considerable improvement.

Estudio de señales cerebrales y aplicación a cojín elevador para discapacitados.

[ES]Estudio de obtención de señales cerebrales, creación de sensores de electroencefalograma y circuito que procesa frecuencias cerebrales para control de un prototipo de cojín elevador que ayude a personas discapacitadas a levantarse de un asiento con el fin de dar los primeros pasos en la creación de un exoesqueleto controlado cerebralmente.

Desarrollo de un prototipo de exoesqueleto básico activado con una señal cerebral.

[ES]En este documento se estudia el desarrollo de una aplicación electrónica para la ayuda a gente con movilidad reducida a través de unos sensores cerebrales que permitan el análisis de la iniciativa de la persona a realizar acciones que de otra manera no podría realizar. El concepto completo consiste en el diseño del sensor que el paciente se colocaría en la cabeza, el tratamiento de la información extraída y la actuación por medio de una solución mecánica, como un conjunto cilindro-pistón para el futuro desarrollo de un sistema de ayuda a la movilidad.

Influência dos receptores opioides no efeito hipotensor arterial do propofol em humanos

O propofol é uma droga hipnótico-sedativa, amplamente utilizada em anestesiologia, devido à sua elevada eficácia hipnótica e ao seu despertar rápido e praticamente isento de efeitos residuais. A depressão cardiovascular, que é o efeito adverso mais importante e indesejável do propofol, parece estar intimamente relacionada à dose administrada, à velocidade de injeção do medicamento, à idade e ao estado físico dos pacientes, assim como, às condições de volemia e de reserva cardiovascular dos mesmos, podendo ser intensificada, ainda, pela associação de uma droga opioide ao propofol. A hipotensão arterial induzida pelo propofol parece possuir uma origem multifatorial, pois já foi evidenciada a participação de diversos sistemas nos efeitos produzidos pelo propofol, inclusive, a participação da via opioide no efeito antinociceptivo da droga. Portanto, o objetivo desse estudo foi investigar a participação dos receptores opioides no efeito hipotensor arterial do propofol. A pesquisa foi do tipo randomizada, transversal, aberta e comparativa. Foram estudados 40 pacientes estado físico ASA 1, submetidos a anestesia geral para cirurgias eletivas. Os desfechos avaliados neste estudo foram as pressões arteriais sistólica (PAS), diastólica (PAD) e média (PAM), a pressão venosa central (PVC) e a frequência cardíaca (FC). Portanto, após a monitorização contínua dos pacientes com cardioscopia com análise de ST, pressão arterial invasiva, pressão venosa central, oxicapnometria, análise eletroencefalográfica bispectral (BIS) e gasimetrias arteriais e venosas, estes foram divididos aleatoriamente através de programa de distribuição aleatória gerada por computador, de acordo com os 5 grupos existentes (n = 8 para todos os grupos). Foram 3 grupos de pacientes pré-medicados intravenosamente (iv) com naloxona 1 μg/Kg (PN1) ou 3 μg/Kg (PN3), ou com salina para controle (CP), 2 minutos antes da administração iv de propofol (2,5 mg/Kg). Outros 2 grupos controle da naloxona foram pré-medicados com naloxona 1 μg/Kg (CN1) ou 3 μg/Kg (CN3), mas não receberam propofol. Os resultados demonstraram que há mais de um mecanismo envolvido no efeito hipotensor arterial do propofol, que é composto por uma rápida redução inicial da PAM opioide-independente e uma lenta redução final da PAM, que foi dependente, ao menos parcialmente, de ação opioide. O propofol, na dose de 2,5 mg/Kg, reduziu a PAS, PAD e PAM de forma significativa e independente do efeito hipnótico do anestésico, dos valores iniciais de PVC e de modificações na FC dos pacientes, apesar de ter sido evidenciada a inibição do baroreflexo induzida pelo anestésico. A hipotensão induzida pelo propofol pôde ser parcialmente reduzida, de forma significativa e dose-dependente, pela prévia administração iv de naloxona de 3 μg/Kg, menor dose efetiva. Este efeito da naloxona ocorreu, principalmente, através de um aumento significativo da PAD, sem importar em modificações significativas da PAS, FC, PVC, BIS ou do ECG. Foi concluído que a hipotensão arterial induzida pelo propofol possui uma origem multifatorial, sendo produzida parcialmente por um mecanismo que é opioide-dependente e sensível ao pré-tratamento dos pacientes com a naloxona. Nosso estudo não recebeu nenhum financiamento externo.

Characterization of the sleep architecture in two species of fruit bat

Bats (Chiroptera) are the second-most abundant mammalian order in the world, occupying a diverse range of habitats and exhibiting many different life history traits. In order to contribute to this highly underrepresented group we describe the sleep architecture of two species of frugivorous bat, the greater short-nosed fruit bat (Cynopterus sphinx) and the lesser dawn fruit bat (Eonycteris spelaea). Electroencephalogram (EEG) and electromyogram (EMG) data were recorded from multiple individuals (>= 5) by telemetry over a 72-h period in a laboratory setting with light/dark cycles equivalent to those found in the wild. Our results show that over a 24-h period both species spent more time asleep than awake (mean 15 h), less than previous reported for Chiroptera (20 h). C sphinx spent significantly more of its non-rapid eye movement sleep (NREM) and rapid eye movement sleep (REM) quotas during the light phase, while E. spelaea divided its sleep-wake architecture equally between both light and dark phases. Comparing the sleep patterns of the two species found that C. sphinx had significantly fewer NREM and REM episodes than E. spelaea but each episode lasted for a significantly longer period of time. Potential hypotheses to explain the differences in the sleep architecture of C. sphinx with E. spelaea, including risk of predation and social interaction are discussed. (C) 2010 Published by Elsevier B.V.

Confidence in beliefs about pain predicts expectancy effects on pain perception and anticipatory processing in right anterior insula.

Psychological factors play a major role in exacerbating chronic pain. Effective self-management of pain is often hindered by inaccurate beliefs about the nature of pain which lead to a high degree of emotional reactivity. Probabilistic models of perception state that greater confidence (certainty) in beliefs increases their influence on perception and behavior. In this study, we treat confidence as a metacognitive process dissociable from the content of belief. We hypothesized that confidence is associated with anticipatory activation of areas of the pain matrix involved with top-down modulation of pain. Healthy volunteers rated their beliefs about the emotional distress that experimental pain would cause, and separately rated their level of confidence in this belief. Confidence predicted the influence of anticipation cues on experienced pain. We measured brain activity during anticipation of pain using high-density EEG and used electromagnetic tomography to determine neural substrates of this effect. Confidence correlated with activity in right anterior insula, posterior midcingulate and inferior parietal cortices during the anticipation of pain. Activity in the right anterior insula predicted a greater influence of anticipation cues on pain perception, whereas activity in right inferior parietal cortex predicted a decreased influence of anticipatory cues. The results support probabilistic models of pain perception and suggest that confidence in beliefs is an important determinant of expectancy effects on pain perception.

Study on the localization of the electric dipole sources

The research of dipole source localization has great significance in both clinical research and applications. For example, the EEG recording from the scalp is widely used for the localization of sources of electrical activity in the brain. This paper presents a closed formula that describes the electric field of dipoles at arbitrary position, which is a linear transformer called the transfer matrix. The expression of transfer matrix and its many useful characteristics are given, which can be used for the analysis of the electrical fields of dipoles. This paper also presents the closed formula for determining the location and magnitude of single dipole or multi-dipoles according to its electrical field distribution. A calculation result for a single dipole shows that the dipole will be located at the midpoint of a line segment if there are equivalent fields at its two ends.

吗啡给药及戒断期间大鼠眶额叶脑区功能活动特征户外环境下自由活动猕猴顶叶及海马神经元单位放电的胞外记录方法

已有的研究表明，眶额叶在解剖上与现在已知的药物滥用相关的脑区是紧密联系在一起的。例如，眶额叶在药物滥用和强迫性重复行为中起作用，且随着脑成像技术的应用，越来越多的证据表明眶额叶参与了药物滥用。但是我们并不了解在阿片给药和戒断期间眶额叶脑区活动是如何变化的。因此，我们在实验中采用了Mn2+增强的核磁共振成像（Manganese-enhanced magnetic resonance　imaging，MEMRI，4.7T）技术和脑电（EEG）记录的方法，以研究大鼠眶额叶在给与阿片类药物（盐酸吗啡）以及戒断过程中的动态变化。 MEMRI是一种近年才发展起来的新型技术。研究表明，Mn2+是Ca2+的类似物，可以通过Ca2+通道进入兴奋性的神经元里面并结合到胞内的蛋白质和核酸上的Ca2+和Mg2+结合位点上 (MILDVAN and COHN, 1963; EISINGER et al., 1965)。另外，Mn2+的顺磁性也为它成为核磁共振成像的造影剂提供了前提条件。可是成功应用MEMRI的前提就是要在适当的时间把合适剂量的Mn2+传递到靶点上。因此，Mn2+在注射到靶点后，是否能够在有效的时间内反映大脑活动的变化就成为一个非常重要并且在技术上较为棘手的问题。在给实验大鼠脑区微量注射Mn2+（80mMol/L，200nl）的同时，通过微量注射兴奋性神经递质谷氨酸（Glu 0.5mM/L）或抑制性递质γ-aminobutyric acid（GABA 0.5M/L）以改变靶点神经元兴奋性的方法，检测Mn2+能否反映脑区的活动变化。另外，我们随机选取实验动物，分别在注射Mn2+ 3小时、5小时和8小时后对三组大鼠（n=5）进行10％福尔马林灌流，并且通过观察大鼠眶额叶脑区Mn2+强度的变化来研究最佳的灌流时间。我们的实验结果表明，Mn2++Glu组的右侧脑区/左侧脑区的Mn2+亮度比Mn2+空白对照组增加了20％（p=0.016, student t-test, *p <0.05），也远大于Mn2++GABA组（p=0.047, *p<0.05）。结果表明，当神经元被兴奋的时候，较多的Mn2+可以通过Ca2+通道进入兴奋的神经元内，使得Mn2+的成像亮度增加。由于Mn2+成像亮度的增加可以反映神经元的兴奋活动，因此可以显示出靶点区的脑活动。另外，在研究灌流时间对Mn2+亮度影响的实验中发现，注射Mn2+ 5小时后灌流得到的信噪比分别比注射Mn2+3小时（p＝0.055）和8小时（p=0.004，*p<0.05）高出24％和32％。总之，我们采用微量注射Mn2+（80mM/L,200nl）后5小时用10%福尔马林心脏灌流的方法获得了较好的结果。另外在试验中我们首先观测了大鼠吗啡戒断后的行为学指标和检测大鼠戒断后条件化位置偏好的程度。实验结果表明大鼠可以建立非常明显的条件化位置偏好，但在湿狗抖等行为学指标上无明显症状。这说明大鼠对于吗啡(10mg/kg, 一天两次，持续12天)形成了明显的心理依赖而无明显的生理依赖。此外，MEMRI的结果表明，在吗啡给药的第1天和第6天，大鼠眶额叶的Mn2+强度与空白对照组相比有显著的降低( one-way ANOVA, Post Hoc Dunnett’s C Tests), F (6,28)=7.242, P<0.001)；而在戒断第3天又恢复到正常水平，在戒断第5天和第7天Mn2+强度跟空白对照组相比没有显著性差别(one-way ANOVA, *p<0.05)。脑电（EEG）的结果表明，急性吗啡诱导的gamma波段的EEG显著降低(Two-way ANOVA, F(1,10)=13.626,p=0.006)。然而在戒断第1天gamma波段的EEG与空白对照组相比是增加的。在戒断第3天和戒断第5天，gamma波段的EEG与空白对照组相比也有显著性增强。以上研究结果表明：大鼠眶额叶脑区的动态变化与整个吗啡给药和戒断过程是密切相关的；此外，MEMRI在探讨药物滥用以及成瘾等机制上有很大的应用前景。

抑制前额叶和海马的星形胶质细胞功能对大鼠工作记忆的影响，长期服用芬克罗酮改善老年大鼠学习记忆障碍的突触可塑性机制

长期以来，星形胶质细胞（astrocyte，AS）被认为具有细胞隔离、支持、保护和营养神经元的作用。近来，人们逐渐发现，AS还有许多其他重要的功能。例如，谷氨酸是中枢神经系统中重要的兴奋性神经递质，AS摄取和合成谷氨酸的作用可能影响学习、神经发育及发情周期等多种脑功能，并影响突触形成和突触传递效能。有研究发现，成年海马齿状回颗粒下层具有神经干细胞潜能的AS，可以分化成新生神经元。此外，海马成熟的AS还参与调节神经发生，决定神经干细胞的分化方向。大鼠海马新生神经元与海马依赖性记忆（happocampal- dependent memory）密切相关。提示，AS与学习记忆密切相关。但迄今为止，尚未见AS参与工作记忆的报道。本研究以特异性抑制AS细胞的化合物fluorocitrate（FC）作为工具药来探讨AS在大鼠工作记忆中的作用及作用机制。FC可抑制AS三羧酸循环中乌头酸酶（aconitase）的活性，从而抑制AS摄取谷氨酸的功能，其作用是可逆的，目前已经被广泛用于研究AS的功能。我们通过慢性导管在大鼠双侧前额叶（prefrontal cortex，PFC），双侧海马（hippocampus，HIP）和单侧侧脑室（lateral ventricle，LV）分别注射FC，记录注射后15-75min内自由活动大鼠的脑电图（EEG）功率变化，以判断FC对大鼠PFC和HIP神经元兴奋性的影响，并在注射后15-75min内完成T-迷宫空间交互延缓(spatial delayed alternation task)反应测试，分析动物的空间工作记忆功能。结果发现在双侧PFC和双侧HIP分别注射1，2，5nM FC （0.5μl），仅2，5nM显著增加HIP EEG的功率（ p < 0.05 vs. SAL），但对交互延缓反应成绩无明显影响，所有剂量对PFC的EEG功率没有显著影响，且不影响动物操作交互延缓反应作业的成绩（ALL p > 0.1 vs. SAL）。在单侧LV注射0.05，0.5nM FC （10μl）后，PFC的EEG功率没有明显变化，而HIP的EEG功率有增加。该剂量的FC对大鼠操作空间交互延缓作业的成绩无明显影响。在单侧LV注射2nM FC（10μl）同时显著增加PFC和HIP的EEG功率，并显著提高大鼠操作空间交互延缓反应作业中的正确率，改善大鼠的工作记忆（ p < 0.05 vs. SAL）。单侧LV注射5nM FC（10μl）同时显著降低PFC和HIP的EEG功率（ALL p < 0.05 vs. SAL）和大鼠操作作业的正确率，损伤大鼠的工作记忆（ p < 0.05 vs. SAL）。表明只有在PFC和HIP的EEG功率同时受到影响的时候，大鼠操作作业的正确率才会发生显著改变。已有研究指出，前额叶和海马均参与工作记忆调控。在LV给FC将同时作用于双侧PFC和双侧HIP。因此，我们认为，FC对大鼠空间交互延缓作业成绩的影响可能是通过抑制PFC和HIP的AS功能产生的。在单侧LV注射低浓度（0.05，0.5nM）的FC对大鼠空间交互延缓作业成绩和EEG功率水平均无明显影响，可能与脑内AS的功能尚可，谷氨酸水平升高不明显有关，而高浓度（5nM）FC可能较强地抑制AS摄取胞外谷氨酸的功能，胞外谷氨酸水平过度升高，损伤神经元的活性，使EEG功率降低，结果导致工作记忆受损。高浓度FC也可能直接损伤神经元的活性。本研究结果表明，FC短期抑制PFC和HIP的AS功能，将使PFC和HIP胞外谷氨酸水平升高，从而改变PFC和HIP神经元的兴奋性，使大鼠的空间工作记忆功能发生改变。揭示了工作记忆不仅依赖于PFC-HIP回路中神经元的正常功能，也与PFC-HIP回路中AS的功能正常与否密切相关。

1.初级视觉皮层功能，GABA系统功能在衰老过程中的变化; 2.奖赏机制，极低频磁场的生物学效应研究

1 初级视觉皮层功能，GABA系统功能在衰老过程中的变化 本章首先对衰老过程中神经形态学和神经电生理学上的研究进行了综述，然后报道了作者的博士学位论文研究工作。实验采用神经电生理的手段，探讨初级视觉皮层（primary visual cortex；V1）功能，以及GABA（gamma-aminobutyric acid）系统功能在衰老过程中的变化。 实验1和2均采用单细胞记录技术，检测了中年猴V1细胞的方位选择性、方向选择性、自发放和最大反应，并与年轻和老年猴进行对比；比较了年轻和老年猴V1细胞的感受野外周抑制能力。在实验3中，我们记录了年轻和中年大鼠在给予GABA直接或间接的激动剂，戊巴比妥钠或氯胺酮{通过拮抗NMDA（N-methyl-D-aspartate）受体}后，其皮层的EEG（electroencephalogram）活动，并分析与年龄相关的差异。结果如下： 实验1：中年猴V1细胞的方向选择性和自发放介于年轻猴和老年猴之间，而方位选择性和最大反应与年龄之间没有相关性。 实验2：感受野外周区的最优刺激明显降低了年轻和老年猴具有高方位选择性细胞的比例。同时，年轻猴所有细胞，以及老年猴高方位选择性细胞具有较高的最大抑制比，与它们相比，老年猴无明显方位偏好细胞的最大抑制比显著降低； 实验3：戊巴比妥钠注射后，在年轻和中年大鼠上，alpha (8-12 Hz) 和beta (12-20 Hz) 频段EEG功率增加，theta (4-8 Hz) 功率减少，这些变化在中年大鼠上较为明显。氯胺酮注射后，中年大鼠theta功率比年轻大鼠具有更大幅度的降低。 我们的结果表明，视觉皮层功能的下调在衰老早期就已发生，其机制可能与抑制系统功能普遍降低有关. 2 奖赏机制，极低频磁场的生物学效应研究 本章首先对自然奖赏和药物成瘾机制、极低频磁场生物学效应，以及极低频磁场对奖赏系统的影响进行了综述，然后报道了作者的博士论文研究工作。实验目的是探讨大鼠眶额叶皮质（orbitofrontal cortex；OFC）活动与食物奖赏刺激的相关性，以及极低频磁场对小鼠空间认知能力的影响。 实验1采用EEG记录技术，检测了大鼠OFC在食物奖赏和渴求过程中EEG各频段的功率变化。在实验2中，使用了一种探索型Y-迷宫实验范式，它仅依赖于啮齿类动物天生的探索欲望，避免了奖赏效应的干扰，利用此新型迷宫，我们检测了25和50 Hz磁场对小鼠空间识别记忆能力的影响。其结果如下： 实验1：大鼠OFC的delta频段（2-4 Hz）EEG活动与食物刺激显著相关，其相对功率在食物渴求时下降，在食物奖赏时升高。 实验2：与短时照射相比，长时的50 Hz磁场照射降低了小鼠对新异臂的探索能力，而25和50 Hz磁场暴露都不影响小鼠的活动力。 本研究表明，食物奖赏与OFC的delta频段EEG活动密切相关，而我们以前发现，大鼠和猴OFC的gamma（20-100 Hz）活动与吗啡成瘾相关，提示了OFC在自然奖赏和药物成瘾中具有不同的作用；另外，本实验首次证明，极低频磁场损害了小鼠不依赖于奖赏系统的空间认知能力，而我们先前发现，极低频磁场可以强化吗啡诱导的条件化位置偏好，从而说明极低频磁场对吗啡成瘾具有独特的生物学效应。

6-12岁儿童自发脑电频谱相干的发展及认知水平的脑诱发电位研究

发展心理学中关于儿童心理发展一直以来存在阶段论和连续论两种观点，阶段论和连续论都有各自的支持依据，但目前心理学家倾向于认为儿童心理发展是阶段性和连续性的统一，一些脑电生理的数据也支持这一观点，脑电发展对认知发展有很好的提示作用。但现有的脑电生理研究在探讨这一问题尚存在一些不足。由于童年中期是个体发育成熟前的最后一个关键期，大脑重量、额叶发育都非常显著，因此，本研究自童年中期大脑发育的特点入手，从自发脑电和诱发脑电两个角度考察童年中期儿童自发脑电基本频谱相干的发展特点及不同认知发展水平、不同年龄的儿童认知发展与脑电发展的关系。研究一主要考察童年中期自发脑电频谱相干发展特点；研究二考察重量守恒水平不同的儿童在完成重量守恒任务时的脑电活动的时间进程；研究三考察不同年龄儿童完成认知任务的脑诱发电位表现。所得结果如下： 1. 自发脑电频谱相干研究发现在童年中期大脑发育存在7-8岁的加速期，并在11岁存在转折，在9、12岁达到高峰。支持儿童发展是阶段性和连续性的统一的观点。 2. 不同守恒水平儿童在完成重量守恒任务时，主要表现为晚正成分的波幅差异，且波幅存在守恒水平与电极位置的交互作用，守恒组倾向于激活右侧额中央区，而不守恒组则倾向于激活中央额区。结果不能支持阶段论，但发展是否表现为连续性，有待于进一步探索。 3. 9-10-11岁三组儿童在完成同一任务时的大脑活动存在显著差异，在脑电水平上，主要表现为N2波幅和电位图的差异，11岁组明显不同于9、10岁组。进一步考察9岁组、10岁普通智力组、10岁高智力水平组、11岁组四组儿童的诱发电位特点（潜伏期、波幅和电位图），发现，9岁组与10岁普通智力组之间N2波幅和电位图差异不显著，而10岁高智力水平组与11岁组在N2波幅和电位图上差异不显著。本实验结果提示认知发展在不同年龄段表现为阶段性，而由于同一年龄段的不同水平与其他年龄组存在水平相当的现象，认知发展从整体上看来表现为一定的连续性。 综合EEG与ERP的研究结果，得出结论，童年中期认知发展和脑电发育是阶段性和连续性的统一。

负性情绪对分泌型免疫球蛋白A的影响以及事件相关电位的关联变化

Although the influence of emotional states on immune function has been generally recognized, researches on the effects of negative emotion on individual SIgA levels have reported mixed findings. Our study aimed to elucidate the relationship between changes in EEG activity and cognitive and psychological mechanisms to the immune changes induced by negative emotion. In experiment one, we investigated how the negative emotional arousal that was induced by watching a number of unpleasant pictures altered the concentration of secretory immunoglobulin A (SIgA). Although our results found discrepancies in the changing tendency of SIgA concentration among participants (some participants’ SIgA decreased after watching unpleasant pictures, whereas others increased), further analysis revealed a coherency among the changing of SIgA concentration, participants’ general coping styles and their actual emotion regulation strategies in perceiving unpleasant pictures, and the event-related potentials (ERPs) associated with the watching of unpleasant pictures. The participants whose SIgA increased after watching unpleasant pictures (the increasers) had higher positive coping scores in the Trait Coping Styles Questionnaire (TCSQ) than those whose SIgA decreased (the decreasers). Also, relative to the decreasers, the increasers tended to use more emotion regulation strategies especially when the presented pictures were extremely negative and exhibited a reverse dissociation pattern between the extremely negative pictures and the moderately negative ones in the amplitude of late positive potential (LPP) that was related to the cognitive evaluation of stimuli’s meaning. On this basis, Event-related potentials were recorded first while participants passively viewed unpleasant pictures, and then during an emotion regulation block in which participants were instructed to reappraise unpleasant pictures in the experiment two. We also collected the immune index before and after the passive viewing block and the emotion regulation block. Our study proved that participants felt a less intense emotional response to unpleasant pictures that followed a reappraisal instruction. The decreasing emotional responding to unpleasant pictures decreased the amplitude of the LPP. But larger N2 was induced in the emotion regulation block, because the participants needed to obtained more attentional resources to detect and integrate more stimulus features to use the cognitive reappraisal strategy effectively. The present study has important theoretic and practical significance. For the theoretic significance, our study elucidated the relationship between changes in EEG activity and cognitive and psychological mechanisms to the immune changes induced by negative emotion by using the technologies of ERP, experimental interview and psychological measurement. Meanwhile, our study also provided an explanation for the different changing tendencies of SIgA induced by negative emotions, and it plays an important role in further studying the cognitive neural mechanisms of immune level in response to emotion. As to the practical significance, our study suggests that individuals who use active emotion regulation in the face of negative emotion stimuli may experience significantly increases in immune system function, subsequently lowering the possibility of infection.