6～12岁儿童脑电α波频率分布特点与信息加工速度的关系

本研究以 2 2 8名 6～ 12岁儿童为研究对象 ,采用脑电波超慢涨落分析技术 (简称ET) ,重点探讨了与认知功能有关的α波 ( 8～ 13Hz)的分布特点。研究结果表明 :①α波在全脑 12个脑区的比率 ,因频率成分不同而表现出不同的分布特点 ;②α波在左右对称脑区的分布比率也因频率不同而表现出不同的左右脑优势。除左前颞叶的平均频率显著大于右前颞叶外 ,其他左右脑对称区域的平均频率的差异均不显著。α波平均频率的从高到低依次为枕叶、中央区、顶叶、左前颞叶、后颞叶、额叶、右前颞叶 ;③信息加工速度与α波的关系并不明显 ,快组和慢组被试的 6种频率 ( 8～13Hz)α波的比率均无显著性差异     

6-12岁儿童脑电α波的发展特点

本研究以228名6～12岁儿童为研究对象,采用脑电波超慢涨落分析技术(简称ET),对其12导联脑电波(EEG)进行了记录和分析,重点探讨了α波(8～13Hz)的发展特点.结果表明:①随着年龄的增长,不同频率的α波成分表现出不同的年龄特点.②α波不同成分的比率没有明显的性别差异.③儿童α波的优势成分随年龄变化而改变.④不同年龄被试α波的平均频率存在显著差异,随着年龄的增长,6～12岁儿童α波的平均频率呈明显的上升趋势,但男女之间没有显著的性别差异.     

社会创造性的脑机制:状态与特质的EEGα波活动特点

采用社会问题情境,通过记录38名高、低特质社会创造性被试在社会问题解决过程中的脑电活动,考查不同特质社会创造性的被试在表现不同状态社会创造性时的脑电激活模式。结果表明:无论高频还是低频α波同步化都存在状态创造性的主效应。同时,高、低频段的α波同步化还存在特质创造性与状态创造性之间显著的交互作用,在表现高状态社会创造性时,高特质的被试比低特质的被试出现更高的α波同步化水平。此外,对于高频α波同步化,状态创造性、特质创造性以及大脑半球的三重交互作用达到显著性水平,低特质社会创造性的被试在表现高状态社会创造性时,右脑半球比左脑半球出现更强烈的α波同步化,在其他情况下均无显著差异。未来的研究可以采用时间进程分析、纵向研究设计、脑功能成像技术探查社会创造性的脑机制。     

电针影响脑电和睡眠及心境的研究

本研究的目的是．探讨电针对脑电和被试主观感觉(困倦、心境)的影响。我们对24位健康志愿者施以电针．4—6小时后脑电测量表明．θ波的相对功率在额、颞区呈增加趋势．其中Fp1、Fp2、F3、F4、C3、C4,F7、F8、T5显著增加;α波的相对功率呈减少趋势,其中αI相对功率在左侧额、颞区Fp1、F3、F7、T5显著减少;α2．在F4、C3、C4,O1和T3显著减少;β频段的相对功率有增有减．其中β1在C3、C4显著减少,在O2、T3、T4显著增加;β2的相对功率在F3、C3显著减少,O1、O2T4、T5、T6显著增加。电针后的问卷调查表明,多数被试有困感,电针对睡眠深度、睡眠时间、醒来次数以及晨间心境有不同程度影响。     

坐忘、正念、冥想治疗焦虑的心理与脑电变化研究

采用不同压力管理策略(坐忘、正念、冥想)考察其对焦虑的干预效用,并用脑电探究其脑机制差异。首先用焦虑量表筛选出高焦虑被试60名,随机分入坐忘、正念、冥想和对照组,并对被试实施持续4周的干预,用焦虑量表进行后测,再采用EEG比较脑电波差异。研究发现:坐忘、正念与冥想都能降低个体的状态焦虑,坐忘对降低特质焦虑作用更大(t_(TAI)=-3.14,P0.01);坐忘在额叶激活了更高的α波,正念在顶叶激活了更高的θ波,冥想组α波的均值高于对照组。因此,不同的压力管理策略对焦虑的干预效用显著,而且三者的脑电存在差异。     

不同类型音乐对悲伤情绪舒缓作用的EEG研究

该研究采用EEG法探究音乐对悲伤情绪舒缓作用。选取中国古典、流行、摇滚及班得瑞音乐及悲伤影片。播放影片诱发悲伤情绪后,用音乐进行舒缓,同步采集脑电,分析得脑电功率谱(PS)及重心频率(GF)。结果表明,影片显著降低了GF及α频段PS;古典音乐GF最高,且诱发的α段PS最高,摇滚乐最低;脑对音乐加工的性别差异显著,半球差异不显著;主观体验悲伤度与α波PS显著负相关。所选音乐均具情绪舒缓作用,中国古典音乐最佳;α波PS,可作为反映悲伤-快乐情绪体验变化的脑电指标。     

书法负荷对大脑两半球反应时影响的探索性研究

高尚仁(1986)在书法心理学研究中发现,中国人在书写书法时脑电活动率(β/α)显著增长,大脑右半球脑电活动率高于左半球,而且有书法经验者大脑右半球脑电活动率提高的幅度较左半球明显为高。因此他认为右半球在书法功能上占优,书法经验有影响两半球功能分工的趋势。但他的研究未能发现书法前后脑电活动率的差异。本研究以大学生被试书写书法负荷前后反应时的变化来探测左、右半球活动能力的变化情况,以期从反应能力上进一步证实高尚仁的研究。     

健康男孩和女孩脑电波的发展——一个追踪研究的结果

 利用连续脑电波图,花了七年时间追踪研究了47名男性和49名女性被试(年龄:4—17岁).分析了儿童期和青年期各种脑电波参数的背景活动和局部解剖分布;考查了个体间的差别、与年龄相关的变化、性别差异及不同脑电波参数的发展速率.发现:4至17岁这段时间,σ波减少而α波增加.女孩比男孩更多地表现为:在枕叶先增加α慢波,减少σ波.随后,这种变化减少,同时α快波增加.     

人类镜像系统参与音乐情绪的自动加工：来自EEG的证据

大脑中线电极诱发的μ抑制波(包括α和β频段)是人类镜像系统活动的电生理指标。尽管音乐情绪表现被认为是通过模仿个体的心理状态来实现的, 但是尚未有研究探讨人类镜像系统与音乐情绪加工的关系。本研究通过EEG技术, 采用跨通道情绪启动范式, 探究人类镜像系统是否参与和弦情绪的自动加工。愉悦或不愉悦的和弦启动情绪一致与不一致的目标面孔。行为结果显示, 被试对情绪一致面孔的反应显著快于情绪不一致面孔的反应。EEG结果显示, 在听觉刺激出现后的500~650 ms之间, 与情绪一致条件相比, 情绪不一致条件诱发了β频段的去同步化。在听觉刺激出现后的300~450 ms, 无论是情绪一致, 还是不一致条件, 都诱发了α频段的去同步化。源分析结果显示, μ抑制波主要出现在人类镜像系统的相关脑区。这些结果表明, 音乐情绪的自动加工与人类镜像系统的活动密切相关。     

儿童亲社会行为发展研究述评

有关儿童亲社会行为的早期研究多集中在发展趋势上。一些研究发现,儿童很早就表现出亲社会行为的倾向,最初的亲社会行为伴随具体、确定的奖赏,以后逐渐发展为自发自愿、不求外加报酬的利他行为。Stabu的研究发现,儿童的助人行为是随着年龄的增长而变化的,5岁至8岁期间的助人行为是随着年龄的增加而增加的,而9岁至12岁期间的助人行为呈下降趋势。顾鹏飞、李伯黍的研究发     

Cyclic cortical reorganization during early childhood.

EEG coherence was computed from 8 left and 8 right intrahemispheric electrode pairs from 253 children ranging in mean age from 6 months to 7 years. The first derivative of mean coherence was computed in order to study growth spurts or rapid changes in mean coherence over the early childhood period. Growth spurts in EEG coherence were approximately 6 months to 1 year in duration and involved a cyclical process composed of a sequential lengthening of intracortical connections in the left hemisphere and a sequential contraction of intracortical connections in the right hemisphere. Each growth spurt cycle had a period of approximately 2 to 4 years and involved both a rostral-caudal expansion and contraction as well as a lateral-to-medial rotation. Data support the view that the functions of the left and right hemisphere are established early in human development through complementary developmental sequences and that these sequences appear to recapitulate differences in adult hemispheric function.     

Variations in EEG coherence as an index of the affective content of dreams from REM sleep: relationships with face imagery

EEG coherence was examined in relation to four measures of socioemotional dream content, including a new measure--the proportional representation of a character's face. Twenty-four healthy subjects, recorded for sleep stages and EEG activity, were awakened from REM sleep to report dream mentation and to rate it on these variables. Coherence scores were calculated for homologous interhemispheric electrode pairs (Fp1-Fp2, F3-F4, F7-F8, C3-C4, P3-P4, O1-O2, T3-T4, T5-T6) and for left and right intrahemispheric pairs for delta, theta, alpha, beta1, and beta2 frequencies. These were correlated with the mentation measures. Positive correlations were found between average interhemispheric coherence in most bands and the character face measure. A breakdown by gender revealed that this relationship was most evident for women, whereas for men positive correlations were observed between coherence and negative self-feeling. That similar relationships also obtained for both left and right intrahemispheric coherence is consistent with the hypothesis that dreamed socioemotional interactions reflect the integrative functioning of many brain regions in both hemispheres.     

Developmental transition of EEG spectra to alpha band in a sample of children with developmental disabilities

Developmental transition of EEG spectra to alpha band of 14 children with developmental disabilities (from 7 yr. and 3 mo. to 16 yr. and 1 mo. of age at the first EEG recording: M= 13.2, SD=2.6; 6 girls and 8 boys) was studied by auto-power spectrum analysis longitudinally. The results showed the mean age (14.1 yr. to 14.8 yr. in the four regions of the frontal, central, parietal, and occipital regions) for subjects and their mean frequency (4.2 Hz to 4.7 Hz in the 4 regions) at which EEG shift started from theta band, and those means (15.1 yr. to 15.7 yr. and 9.5 Hz to 9.6 Hz in the 4 regions) at which EEG shift reached the alpha band. Prior EEG research on healthy children has shown that approximately 10 years of age is critical for developmental transition of EEG spectra to alpha frequencies. It is suggested that the present data showed a delay of this critical age for this sample of children with developmental disabilities relative to 10 years for healthy children reported by Katada, et al. and Benninger, et al.     

轻度认知功能障碍患者工作记忆中 脑电能量及皮质联络功能的变化特征

探讨轻度认知功能障碍患者（MCI）工作记忆状态下脑电能量及皮质联络功能的变化特征。被试为从社区选取的35名轻度认知功能障碍患者和34名健康志愿者。采用简单计算回忆方法,结果发现工作记忆加工过程中会引起4.0~18.0Hz范围内功率值的改变,且MCI组高于正常对照组;MCI患者在中央、顶、颞叶的半球间相干系数均显著高于正常对照组。研究结果提示MCI患者可能存在中央、顶、颞叶皮层的功能减退,工作记忆状态下通过代偿机制仍能维持加工的有效性     

Modification of EEG power spectra and EEG connectivity in autobiographical memory: a sLORETA study

The aim of the present study was to explore the modifications of scalp EEG power spectra and EEG connectivity during the autobiographical memory test (AM-T) and during the retrieval of an autobiographical event (the high school final examination, Task 2). Seventeen healthy volunteers were enrolled (9 women and 8 men, mean age 23.4 ± 2.8 years, range 19–30). EEG was recorded at baseline and while performing the autobiographical memory (AM) tasks, by means of 19 surface electrodes and a nasopharyngeal electrode. EEG analysis was conducted by means of the standardized LOw Resolution Electric Tomography (sLORETA) software. Power spectra and lagged EEG coherence were compared between EEG acquired during the memory tasks and baseline recording. The frequency bands considered were as follows: delta (0.5–4 Hz); theta (4.5–7.5 Hz); alpha (8–12.5 Hz); beta1 (13–17.5 Hz); beta2 (18–30 Hz); gamma (30.5–60 Hz). During AM-T, we observed a significant delta power increase in left frontal and midline cortices (T = 3.554; p < 0.05) and increased EEG connectivity in delta band in prefrontal, temporal, parietal, and occipital areas, and for gamma bands in the left temporo-parietal regions (T = 4.154; p < 0.05). In Task 2, we measured an increased power in the gamma band located in the left posterior midline areas (T = 3.960; p < 0.05) and a significant increase in delta band connectivity in the prefrontal, temporal, parietal, and occipital areas, and in the gamma band involving right temporo-parietal areas (T = 4.579; p < 0.05). These results indicate that AM retrieval engages in a complex network which is mediated by both low- (delta) and high-frequency (gamma) EEG bands.     

Reduced electroencephalographic coherence asymmetry in the Chernobyl accident survivors

An electroencephalograph (EEG) study was carried out from 1990 to 2006, using power spectra, averaged coherence, and integral EEG coherence asymmetry coefficients to compare 189 clean-up workers of the Chernobyl accident with 63 age-matched healthy controls. Most of the Chernobyl workers showed three abnormal EEG patterns, as indicated by EEG power mapping. The higher power, most prominent in slow alpha and theta bands, or in fast alpha frequencies, were observed in persons 3-5 years after the clean-up works (the early stage). The lower EEG power in alpha band was found in Chernobyl workers 10 or more years after the accident (the late stage). EEG coherence analysis revealed the existence of two stages in EEG alterations following the Chernobyl clean-up. In the early stage, an increase of EEG coherence in the central brain areas was observed, whereas at the later stage, a decrease of EEG coherence, most prominent in the frontal brain areas, and reduced brain asymmetry prevailed. These results allow us to propose that the described EEG signs may be a reflection of radiation-induced brain dysfunction at the late period after the Chernobyl clean-up and were similar to the EEG markers of brain ageing. The results, in comparison to data of the literature, provide additional support to the premature brain ageing hypothesis in Chernobyl survivors as a result of the radiation brain damage after-effect.     

Intellectual disabilities and developmental EEG transition to alpha band: a comment on Shibagaki, et al. (2006)

In 2006 Shibagaki, et al. estimated mean chronological age at which dominant EEG frequency reached alpha band in 11 children with intellectual disabilities (M age, 15 yr.). Consistent with previous studies, the results showed a delay in the critical age relative to healthy children and earlier maturation at posterior scalp sites, with the exception of several children who persistently showed EEG slower than alpha band. A flaw in the study might be that having only 2 children younger than 10 yr. was insufficient. A remaining problem for researchers would be to identify whether the developmental delay in EEG correlates with IQ in intellectually disabled children.     

CS-specific gamma,theta, and alpha EEG activity detected in stimulus generalization following induction of behavioral memory by stimulation of the nucleus basalis

Tone paired with stimulation of the nucleus basalis (NB) induces behavioral memory that is specific to the frequency of the conditioned stimulus (CS), assessed by cardiac and respiration behavior during post-training stimulus generalization testing. This paper focuses on CS-specific spectral and temporal features of conditioned EEG activation. Adult male Sprague-Dawley rats, chronically implanted with a stimulating electrode in the NB and a recording electrode in the ipsilateral auditory cortex, received either tone (6kHz, 70dB, 2s) paired with co-terminating stimulation of the nucleus basalis (0.2s, 100Hz, 80-105 microA, ITI approximately 45s) or unpaired presentation of the stimuli (approximately 200 trials/day for approximately 14 days). CS-specificity was tested 24h post-training by presenting test tones to obtain generalization gradients for the EEG, heart rate, and respiration. Behavioral memory was evident in cardiac and respiratory responses that were maximal to the CS frequency of 6kHz. FFT analyses of tone-elicited changes of power in the delta, theta, alpha, beta1, beta2, and gamma bands in the paired group revealed that conditioned EEG activation (shift from lower to higher frequencies) was differentially spectrally and temporally specific: theta, and alpha to a lesser extent, decreased selectively to 6kHz during and for several seconds following tone presentation while gamma power increased transiently during and after 6kHz. Delta exhibited no CS-specificity and the beta bands showed transient specificity only after several seconds. The unpaired group exhibited neither CS-specific behavioral nor EEG effects. Thus, stimulus generalization tests reveal that conditioned EEG activation is not unitary but rather reflects CS-specificity, with band-selective markers for specific, associative neural processes in learning and memory.     

Spatiotemporal variations of alpha and sigma band EEG in the waking-sleeping transition period

The aim of this study is to evaluate the spatiotemporal variation of alpha and sigma band EEGs during the waking-sleeping transition or hypnagogic period. Power and coherence from 7 EEG channels (Fp1, F7, Fz, C3, Pz, T5, O1) were studied using EEG records of the period of 5 min. before the onset of Stage 1 to 24 min. after the onset of Stage 1. The EEG spectra were computed for 4 frequency bands (alpha 1: 8.0-9.0 Hz, alpha 2: 9.5-11.0 Hz, alpha 3: 11.5-12.5 Hz, and sigma: 13.0-15.0 Hz). The power of alpha 1 and 2 bands initially started to decrease before the onset of Stage 1. Principal component analysis of the coherence yielded Generalized and Localized Components in each band. The Generalized Component was widespread across scalp areas, while the Localized Component was a restricted local area. The Generalized Components of alpha 1 and 2 bands reached stable levels of NREM sleep about 1 min. after the onset of Stage 1. The component of sigma band reached a stable level of NREM sleep about 0.6 min. before the onset of Stage 2, while the component of alpha 3 band reached a stable level of NREM sleep about 3.4 min. after the onset of Stage 2. These results suggest that the alpha-sigma band EEG structures during the waking-sleeping transition period may not be uniform across EEG bands and that the hypnagogic EEG changes may start before the onset of Stage 1 and continue for several minutes after the onset of Stage 2.     

Electrophysiological spatiotemporal dynamics during implicit visual threat processing

Numerous studies have found evidence for corticolimbic theta band electroencephalographic (EEG) oscillations in the neural processing of visual stimuli perceived as threatening. However, varying temporal and topographical patterns have emerged, possibly due to varying arousal levels of the stimuli. In addition, recent studies suggest neural oscillations in delta, theta, alpha, and beta-band frequencies play a functional role in information processing in the brain. This study implemented a data-driven PCA based analysis investigating the spatiotemporal dynamics of electroencephalographic delta, theta, alpha, and beta-band frequencies during an implicit visual threat processing task. While controlling for the arousal dimension (the intensity of emotional activation), we found several spatial and temporal differences for threatening compared to nonthreatening visual images. We detected an early posterior increase in theta power followed by a later frontal increase in theta power, greatest for the threatening condition. There was also a consistent left lateralized beta desynchronization for the threatening condition. Our results provide support for a dynamic corticolimbic network, with theta and beta band activity indexing processes pivotal in visual threat processing.