高功能自闭症儿童面孔加工的ERP研究

目的:探讨7-9岁高功能自闭症儿童面孔加工时事件相关电位(Electrical event-relateds,ERP)的变化及其意义。方法:选择7-9岁自闭症儿童(实验组)与普通儿童(对照组)各15名,以中国人中性面孔及常见物件为刺激材料,记录和比较两类儿童在面孔刺激下的脑电成分。结果:剔除无效数据后,有效被试:实验组12人、对照组14人,两组年龄和性别组成无显著性差异(P0.05)。而,自闭症组按键反应时间、面孔反应时间显著长于对照组(按键反应F=9.26,P0.05;面孔反应t=5.32,P0.05)。在面孔刺激因素下,自闭症组平均波峰明显小于对照组(t=4.62,P0.05)。在物件刺激因素下,两组平均波峰无显著差异(t=0.21,P0.05)。而两组的潜伏期组别主效应不显著(F=1.63,P0.05)。结论:自闭症儿童面孔结构编码过程异常,对面孔的关注度比普通儿童低。本文证实了自闭症儿童知觉/认知缺陷的存在,为更进一步研究提供了理论依据。     

高功能自闭症儿童面孔加工的ERP研究

目的：探讨7-9岁高功能自闭症儿童面孔加工时事件相关电位（Electrical event-relateds,ERP）的变化及其意义。方法：选择7-9岁自闭症儿童（实验组）与普通儿童（对照组）各15名,以中国人中性面孔及常见物件为刺激材料,记录和比较两类儿童在面孔刺激下的脑电成分。结果：剔除无效数据后,有效被试：实验组12人、对照组14人,两组年龄和性别组成无显著性差异（P〉0.05）。而,自闭症组按键反应时间、面孔反应时间显著长于对照组（按键反应F=9.26,P〈0.05;面孔反应t=5.32,P〈0.05）。在面孔刺激因素下,自闭症组平均波峰明显小于对照组（t=4.62,P〈0.05）。在物件刺激因素下,两组平均波峰无显著差异（t=0.21,P〉0.05）。而两组的潜伏期组别主效应不显著（F=1.63,P〉0.05）。结论：自闭症儿童面孔结构编码过程异常,对面孔的关注度比普通儿童低。本文证实了自闭症儿童知觉/认知缺陷的存在,为更进一步研究提供了理论依据。     

Dissociation of category versus item priming in face processing: an event-related potential study

The underlying specificity of visual object categorization and discrimination can be elucidated by studying different types of repetition priming. Here we focused on this issue in face processing. We investigated category priming (i.e. the prime and target stimuli represent different exemplars of the same object category) and item priming (i.e. the prime and target stimuli are exactly the same image), using an immediate repetition paradigm. Twenty-three subjects were asked to respond as fast and accurately as possible to categorize whether the target stimulus was a face or a building image, but to ignore the prime stimulus. We recorded event-related potentials (ERPs) and reaction times (RTs) simultaneously. The RT data showed significant effects of category priming in both face trials and building trials, as well as a significant effect of item priming in face trials. With respect to the ERPs, in face trials, no priming effect was observed at the P100 stage, whereas a category priming effect emerged at the N170 stage, and an item priming effect at the P200 stage. In contrast, in building trials, priming effects occurred already at the P100 stage. Our results indicated that distinct neural mechanisms underlie separable kinds of immediate repetition priming in face processing.     

MMN responses during implicit processing of changes in emotional prosody: an ERP study using Chinese pseudo-syllables

In this study, we tested the underlying mechanisms of early emotional prosody perception, especially examined whether change detection in oddball paradigm was caused by emotional category and physical properties. Using implicit oddball paradigms, the current study manipulated the cues for detecting deviant stimuli from standards in three conditions: the simultaneous changes in emotional category and physical properties (EP condition), change in emotional category alone (E condition), and change in physical properties alone (P condition). ERP results revealed that physical property change increased brain responses to deviant stimuli in the EP than in the E condition at early stage 90–160 ms, suggesting that physical property change of emotional sounds can also be detected at the early stage. At the later stage 160–260 ms, the simultaneous and respective changes in emotional category and physical properties were reliably detected, and the sum of the brain responses to the corresponding changes in E and P conditions was equal to the brain responses to the simultaneous changes in EP condition. Source analysis further revealed that stimuli-driven regions (inferior parietal lobule), temporal and frontal cortices were activated at early stage, while only frontal cortices for higher cognitive processing were activated at later stage. These findings suggest that emotional prosody changes in physical properties and emotion category are perceived as domain-general change information in emotional prosody perception.     

面孔分类中空间高低频表征的神经机制：一个颅内脑电研究

来自多方面的研究表明,面孔的分类和识别位于特定脑区．同时,已有行为实验研究表明,图像的空间高低频特征在面孔分类的不同范畴中起不同的贡献,例如身份更多被低频信号传递,性别被高低频共同传递,而表情更多被高频传递．然而,空间频率在面孔分类中的贡献,其表征和神经机制目前相关研究很少．利用特定癫痫患者植入颅内电极的监控期,呈现不同类型面孔图像,同时记录其颅内脑电,用事件相关电位方法考察了据认为是面孔特定成分的相关电位的潜伏期在170 ms的波形(N170波形)的变化;用电极反应显著性分析考察了空间频率在不同分类特征上的贡献．结果表明,空间高频(HSF)图像的N170潜伏期显著延迟．只呈现空间低频(LSF)图像,N170的潜伏期对普通人面孔会延迟,而对熟悉的名人则没有这个差异．女性面孔诱发的N170在HSF条件下潜伏期明显晚于LSF条件,而男性面孔诱发的波形则不存在这个差异．表情在N170上没有体现出任何差异．但是基于电极的显著性分析表明,有更多的额叶电极参与了表情的加工;身份特征加工有更多电极在空间低频上表现出差异,而性别加工则空间高低频比较平衡．与以往行为结果不同的是,表情加工也有更多低频贡献,而且表情的差异可以在早达114 ms的时候就发生．这符合表情信息在颞枕区域有一个快速基本加工,再传递到其他脑区的认知模型．因此,空间高低频信息在身份和性别上的贡献,可能发生在经典的面孔加工脑区,由N170表达,表情信息不由N170表达,而是在颞枕较广泛的范围内快速加工再传递到别的脑区,如额叶．这是首次利用颅内脑电就空间频率在面孔分类中的贡献的神经机制进行研究,为深入理解脑内面孔各种特征加工的动态过程提供了一个新的切入点．     

Effect of empathy trait on attention to various facial expressions: evidence from N170 and late positive potential (LPP)

Background

The present study sought to clarify the relationship between empathy trait and attention responses to happy, angry, surprised, afraid, and sad facial expressions. As indices of attention, we recorded event-related potentials (ERP) and focused on N170 and late positive potential (LPP) components.

Methods

Twenty-two participants (12 males, 10 females) discriminated facial expressions (happy, angry, surprised, afraid, and sad) from emotionally neutral faces under an oddball paradigm. The empathy trait of participants was measured using the Interpersonal Reactivity Index (IRI, J Pers Soc Psychol 44:113–126, 1983).

Results

Participants with higher IRI scores showed: 1) more negative amplitude of N170 (140 to 200 ms) in the right posterior temporal area elicited by happy, angry, surprised, and afraid faces; 2) more positive amplitude of early LPP (300 to 600 ms) in the parietal area elicited in response to angry and afraid faces; and 3) more positive amplitude of late LPP (600 to 800 ms) in the frontal area elicited in response to happy, angry, surprised, afraid, and sad faces, compared to participants with lower IRI scores.

Conclusions

These results suggest that individuals with high empathy pay attention to various facial expressions more than those with low empathy, from very-early stage (reflected in N170) to late-stage (reflected in LPP) processing of faces.     

类别验证任务中否定加工的ERP研究

有研究提出了否定加工的两阶段模拟假说,认为否定加工的第一阶段是模拟被否定的状态,第二阶段是整合否定以模拟真实状态.为了对该假说进行检验,本研究采用ERP技术探讨了20名被试完成类别验证任务时的脑内时程动态变化.任务有4种条件：肯定类别对（例如,蔬菜-白菜）,肯定无关对（例如,蔬菜-蜜蜂）,否定类别对（例如,蔬菜-蜜蜂）和否定无关对（例如,蔬菜-白菜）.其中类别上画有一横线表示＂不是该类别的事物＂,例如,蔬菜表示＂不是蔬菜＂.结果表明,否定类别对比否定无关对和肯定类别对都引发了更负的N400,这说明,否定加工中建立了被否定状态的表征,支持了两阶段模拟假说.此外,肯定类别对比否定类别对引发了更正的LPC,这一结果揭示了两阶段模拟假说中第二阶段即整合否定模拟真实状态的神经机制.可能是因为肯定类别关系的加工涉及再认和记忆信息的提取,而否定类别关系的加工如两阶段模拟假说所预期的包含两个阶段,涉及推理过程,因而前者比后者引发了更正的LPC.     

隐喻加工复合模式的ERP研究

本研究使用S1→S2范式研究中国人大脑隐喻加工模式是否与"等级显性理论"一致。被试对隐喻匹配任务和不相关匹配模式进行"是"和"否"隐喻的判断,同时脑电设备记录他们进行任务加工时的事件相关电位(ERP)。通过对相关电极N400的分析发现,右脑加工两个任务时,激活程度呈递增的趋势,与"等级显性理论"一致。另外,两个任务中顶叶空间加工区参与程度的差异说明,隐喻意义的整合需要对相似性、熟悉度等确定后再进行空间联系。     

Effect of empathy trait on attention to faces: an event-related potential (ERP) study

Background

Empathy is deeply linked with the ability to adapt to human social environments. The present study investigated the relationship between the empathy trait and attention elicited by discriminating facial expressions.

Methods

Event-related potentials were measured while 32 participants (17 men and 15 women) discriminated facial expressions (happy or angry) and colors of flowers (yellow or purple) under an oddball paradigm. The empathy trait of participants was measured using the Interpersonal Reactivity Index (Davis, 1980).

Results

The empathy trait correlated positively with both the early portion (300 to 600 ms after stimulus onset) and late portion (600 to 800 ms after stimulus onset) of late positive potential (LPP) amplitude elicited by faces, but not with LPP elicited by flowers.

Conclusions

This result suggests that, compared to people with low empathy, people with high empathy pay more attention when discriminating facial expressions. The present study suggests that differences exist in methods of adapting to social environments between people with high and low empathy.     

健康早产儿睡眠时闪光视觉诱发电位的自回归分析

本研究旨在探讨闪光视觉诱发电位 (flashvisualevokedpotential,FVEP)与健康早产儿视神经及脑发育间的关系。应用自回归分析法对 36名健康早产儿 (胎龄 2 8周 2天～ 4 2周 )FVEP记录进行了分析 ,平均 8 5个(7～ 11个 )FVEP成分波被检出。依衰减频率分布的直方图将其分为 4组。总功率 (TP)、Ⅰ～Ⅳ组成分波功率(P)、Ⅱ～Ⅳ组衰减时间均随胎龄增加 ,有显著变化 (P <0 0 1orP <0 0 5 )。提示神经系统对闪光刺激的生物电反应在早产儿脑及视神经发育评价上具有重要的临床意义     

The hierarchy of directional interactions in visual motion processing

It is well known that context influences our perception of visual motion direction. For example, spatial and temporal context manipulations can be used to induce two well-known motion illusions: direction repulsion and the direction after-effect (DAE). Both result in inaccurate perception of direction when a moving pattern is either superimposed on (direction repulsion), or presented following adaptation to (DAE), another pattern moving in a different direction. Remarkable similarities in tuning characteristics suggest that common processes underlie the two illusions. What is not clear, however, is whether the processes driving the two illusions are expressions of the same or different neural substrates. Here we report two experiments demonstrating that direction repulsion and the DAE are, in fact, expressions of different neural substrates. Our strategy was to use each of the illusions to create a distorted perceptual representation upon which the mechanisms generating the other illusion could potentially operate. We found that the processes mediating direction repulsion did indeed access the distorted perceptual representation induced by the DAE. Conversely, the DAE was unaffected by direction repulsion. Thus parallels in perceptual phenomenology do not necessarily imply common neural substrates. Our results also demonstrate that the neural processes driving the DAE occur at an earlier stage of motion processing than those underlying direction repulsion.     

Influence of body position on cortical pain-related somatosensory processing: an ERP study

Background

Despite the consistent information available on the physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge on the possible perceptual-cortical alterations is still poor. The present study investigated the effects of 2-h head-down bed rest on subjective and cortical responses elicited by electrical, pain-related somatosensory stimulation.

Methodology/Principal Findings

Twenty male subjects were randomly assigned to two groups, head-down bed rest (BR) or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials were elicited by electrical stimuli administered randomly to the left wrist and divided into four conditions: control painless condition, electrical pain threshold, 30% above pain threshold, 30% below pain threshold. Subjective pain ratings collected during the EEG session showed significantly reduced pain perception in BR compared to Control group. Statistical analysis on four electrode clusters and sLORETA source analysis revealed, in sitting controls, a P1 component (40–50 ms) in the right somatosensory cortex, whereas it was bilateral and differently located in BR group. Controls'' N1 (80–90 ms) had widespread right hemisphere activation, involving also anterior cingulate, whereas BR group showed primary somatosensory cortex activation. The P2 (190–220 ms) was larger in left-central locations of Controls compared with BR group.

Conclusions/Significance

Head-down bed rest was associated to an overall decrease of pain sensitivity and an altered pain network also outside the primary somatosensory cortex. Results have implications not only for astronauts'' health and spaceflight risks, but also for the clinical aspects of pain detection in bedridden patients at risk of fatal undetected complications.     

The syntactic and semantic processing of mass and count nouns: an ERP study

The present study addressed the question of whether count and mass nouns are differentially processed in the brain. In two different ERP (Event-Related Potentials) tasks we explored the semantic and syntactic levels of such distinction. Mass and count nouns typically differ in concreteness, hence the effect of this important variable was factorially examined in each task. Thus the stimuli presented were: count concrete, count abstract, mass concrete or mass abstract. The first experiment (concrete/abstract semantic judgment task) involved the interaction between the N400 concreteness effect and the Mass/Count condition, revealing a substantial effect between mass and count nouns at the semantic level. The second experiment (sentence syntactic violation task) showed a Mass/Count distinction on left anterior negativity (LAN) and on P600 components, confirming the difference at the syntactic level. This study suggests that the brain differentiates between count and mass nouns not only at the syntactic level but also at the semantic level. Implications for our understanding of the brain mechanisms underlying the Mass/Count distinction are discussed.     

Study of effects of low level microwave field by method of face masking

The aim of this study was to examine experimentally effects of low level, modulated microwaves on human central nervous system function utilizing the phenomenon of visual masking. Ten healthy volunteers, four males and six females, were exposed to electromagnetic field (450 MHz, 0.16 mW/cm2) with 7 Hz modulation frequency. Two photo series (visual stimuli) of unfamiliar, young male faces were presented to the subjects, one picture after another. All the photos were frontal views of unfamiliar faces, which could be recognized only by their unique combinations of features. The task was to identify the pictures from a group of six photos and to decide which order they were presented in. The phenomenon of visual masking is revealed as anamorphosis in subject's perception of two instantaneous visual stimuli presented within a short time interval. When both stimuli were to be recognized correctly and put in the right order, there was a statistically significant difference (P < 0.05) between the identification of the stimulus with microwave electromagnetic field and sham exposure. Recognition of both stimuli in a pair was better under the sham exposure conditions but the actual difference was only 5%. It was concluded that early stages of visual information processing are overwhelmingly robust and routine (and adaptively significant) activities, so that the low level 7 Hz modulated electromagnetic field effects exerted upon it are extremely weak.     

Secondary somatosensory area is involved in vibrotactile temporal-structure processing: MEG analysis of slow cortical potential shifts in humans

Abstract

Purpose: Temporal-structure discrimination is an essential dimension of tactile processing. Exploring object surface by touch generates vibrotactile input with various temporal dynamics, which gives diversity to tactile percepts. Here, we examined whether slow cortical potential shifts (SCPs) (<1?Hz) evoked by long vibrotactile stimuli can reflect active temporal-structure processing.

Materials and methods: Vibrotactile-evoked magnetic brain responses were recorded in 10 right-handed healthy volunteers using a piezoelectric-based stimulator and whole-head magnetoencephalography. A series of vibrotactile train stimuli with various temporal structures were delivered to the right index finger. While all trains consisted of identical number (15) of stimuli delivered within a fixed duration (1500?ms), temporal structures were varied by modulating inter-stimulus intervals (ISIs). Participants judged regularity/irregularity of ISI for each train in the active condition, whereas they ignored the stimuli while performing a visual distraction task in the passive condition. We analysed the spatiotemporal features of SCPs and their behaviour using the minimum norm estimates with the dynamic statistical parametric mapping.

Results: SCPs were localized to contralateral primary somatosensory area (S1), contralateral superior temporal gyrus, and contralateral as well as ipsilateral secondary somatosensory areas (S2). A significant enhancement of SCPs was observed in the ipsilateral S2 (S2i) in the active condition, whereas such effects were absent in the other regions. We also found a significant larger amplitude difference between the regular- and irregular-stimulus evoked S2i responses during the active condition than during the passive condition.

Conclusions: This study suggests that S2 subserves the temporal dimension of vibrotactile processing.     

用脑光学成像术研究不同空间拓扑位置猫初级视皮层的空间频率反应特性

采用基于内源信号的脑光学成像方法,在大范围视皮层研究了不同空间拓扑位置对应的皮层区的对光栅刺激空间频率反应特性。结果表明,周边视野对应区对高空间频率刺激反应极弱或没有反应,中心视野对应区对较宽的空间频率范围内的刺激均有反应,但对高频刺激反应更强;无论在周边对应区还是中心对应区,其视野越靠近中心,其空间频率调谐曲线和截止空间频率越靠近高频,而且这种过渡是平缓的。以上结果说明,猫初级视皮层空间频率反应     

Chronic exposure of primates to 60-Hz electric and magnetic fields: III. Neurophysiologic effects

The neurophysiologic effects of combined 60-Hz electric (E) and magnetic (B) fields, of magnitudes comparable to those produced by high-voltage powerlines, were investigated in 10 monkeys (Macaca nemestrina). Six animals (experimental group) were each exposed to three different levels of E and B fields: 3 kV/m and 0.1 G, 10 kV/m and 0.3 G, and 30 kV/m and 0.9 G. Field exposures were preceded and followed by sham exposures, during which factors of field generation were present (e.g., heat, vibration, noise, etc.) without E and B fields. Each of the five segments (i.e., the three exposure segments and the initial and final sham exposure segments) lasted 3 weeks. Animals were exposed for 18 h/day (fields on at 1600 h, off at 1000 h). Four other animals (external control group) were given sham exposure for the entire 15-week period. Auditory, visual, and somatosensory evoked potentials were recorded twice a week, during the daily 6-h field-off period. E- and B-field exposure had no effect on the early or mid-latency evoked potential components, suggesting that exposure at these levels has no effect on peripheral or central sensory afferent pathways. However, there was a statistically significant decrease in the amplitudes of late components of the somatosensory evoked potential during the 10kV/m and 0.3 G, and 30 kV/m and 0.9 G exposure levels. This result is possibly related to the opiate antagonist effect of electromagnetic field exposure reported by others.     

单眼远视性弱视儿童P-VEP检查的临床研究

目的:分析单眼远视性弱视儿童图形视觉诱发电位(P-VEP)检查情况,探讨外周发病机制,为临床诊疗提供依据。方法:选取2013年1月到2015年10月我院收治的单眼远视性弱视儿童75例(75只眼),另选取同期正常儿童32例(64只眼)为对照组,根据病情将弱视儿童分为轻度(A组)和对侧健眼组(B组),中度(C组)和对侧健眼组(D组),重度(E组)和对侧健眼组(F组),应用P-VEP检查各组P100波及振幅。结果:A组、C组、E组P100波潜伏期较B组、D组、F组和对照组延长(P0.05),振幅较B组、D组、F组和对照组降低(P0.05),A组、C组和、E组P100波潜伏期和振幅比较具有统计学意义(P0.05),B组、D组、F组P100波潜伏期与对照组无统计学意义(P0.05),B组、D组、F组振幅显著低于对照组(P0.05),B组、D组、F组P100波潜伏期和振幅比较无统计学意义(P0.05)。结论:单眼远视性弱视儿童弱视眼会出现P100波潜伏期延长,振幅降低,对侧健康眼会出现振幅降低。     

Causal evidence for the processing of bodily self in the anterior precuneus

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