人脑自适应多尺度功能连接的性别差异

已有脑成像研究展示了男女脑功能差异, 但功能磁共振信号的频率划分通常基于主观经验, 使脑功能性别差异的生物学解释遭遇瓶颈。本文提出人脑自适应多尺度功能连接算法, 刻画功能连接的时空多尺度特性, 揭示出0.06~0.10 Hz的性别差异：男性较强的连接主要与边缘网络和腹侧注意网络有关, 女性较强的连接主要与腹侧注意网络、视觉网络和额顶网络有关。     

抑郁症的脑功能异常:来自静息态功能磁共振成像的证据

静息态功能磁共振成像是指在静息状态下测量的BOLD信号,即受试者安静地躺在扫描仪中,不给受试者任何特定的任务,受试者也不用做任何反应,此时受试者的大脑活动处于自发状态。通过使用该技术可以为抑郁症发作的临床现象提供神经影像学依据,以期为将来抑郁症的治疗提供生物标记。因此,本文综述了大量抑郁症患者在静息态脑功能方面的差异研究,发现了单、双相抑郁症,首、复发抑郁症,早发性、晚发性抑郁症,难治、非难治性抑郁症等不同类型的抑郁症在包括局部一致性(Re Ho)和低频振幅(ALFF)在内的功能分化以及包括功能连接密度(FCD)、功能同伦(VMHC)、复杂网络(Complex Network)和ROI功能连接在内的功能整合两大指标的改变。     

Extraversion modulates functional connectivity hubs of resting‐state brain networks

Personality dimension extraversion describes individual differences in social behaviour and socio‐emotional functioning. The intrinsic functional connectivity patterns of the brain are reportedly associated with extraversion. However, whether or not extraversion is associated with functional hubs warrants clarification. Functional hubs are involved in the rapid integration of neural processing, and their dysfunction contributes to the development of neuropsychiatric disorders. In this study, we employed the functional connectivity density (FCD) method for the first time to distinguish the energy‐efficient hubs associated with extraversion. The resting‐state functional magnetic resonance imaging data of 71 healthy subjects were used in the analysis. Short‐range FCD was positively correlated with extraversion in the left cuneus, revealing a link between the local functional activity of this region and extraversion in risk‐taking. Long‐range FCD was negatively correlated with extraversion in the right superior frontal gyrus and the inferior frontal gyrus. Seed‐based resting‐state functional connectivity (RSFC) analyses revealed that a decreased long‐range FCD in individuals with high extraversion scores showed a low long‐range functional connectivity pattern between the medial and dorsolateral prefrontal cortex, middle temporal gyrus, and anterior cingulate cortex. This result suggests that decreased RSFC patterns are responsible for self‐esteem, self‐evaluation, and inhibitory behaviour system that account for the modulation and shaping of extraversion. Overall, our results emphasize specific brain hubs, and reveal long‐range functional connections in relation to extraversion, thereby providing a neurobiological basis of extraversion.     

运动技能水平与躯体感觉输入对运动表象的影响

运动表象质量与运动技能水平有关,运动表象质量随着运动技能水平的提高而上升。器械使用可使人脑产生可塑性改变,使用者会将器械纳入身体图式。然而,两者影响运动表象的神经心理机制还不清楚。本研究采用功能性磁共振成像探析篮球运动员与新手在不同持球条件下表象投篮时脑功能活动的差异。结果表明运动员表象质量较好,镜像神经系统激活高于新手;持球条件下运动员表象质量显著高于不持球条件下,镜像神经系统激活程度显著低于不持球条件下。研究说明持器械可以显著提高运动员的表象质量,器械使用带来镜像神经系统的可塑性变化。     

阿尔兹海默症及轻度认知障碍静息态大尺度脑网络功能连接的改变

静息态功能磁共振成像作为非侵入性可视化成像方法, 且数据采集简便易行, 已成为探索阿尔兹海默症及轻度认知障碍脑功能变异的主要成像手段。近年来静息态研究显示在其前驱症状期轻度认知障碍阶段患者已显现出静息态脑网络的变异, 而阿尔兹海默症患者的网络改变更加弥散。研究发现随着病程推进, 患者显示出默认网络连接逐渐减弱以及额叶认知网络连接先增强后减弱的整体趋势。此外, 脑结构和功能网络的改变并非单向因果关系, 二者在病程进展中存在交互作用。未来研究可以从诊断的标志性神经通路、疗效的大尺度脑网络标记, 以及疾病的异质性等角度入手, 进一步探索静息态脑网络作为阿尔兹海默症诊断和病程监控指标的可能性。     

青老年组不同难度下心算活动的脑功能磁共振成像研究

应用功能磁共振成像技术研究不同心算难度下脑区的活动以及年龄的影响。14名志愿者（20～29岁青年和60～69岁老年被试各7名）参加了该实验。实验任务为2个难度水平的连续减法心算,分别为1000—3和1000—17。结果表明：（1）心算加工激活了额叶和顶叶的许多脑区;（2）大脑左半球是心算加工的优势半球,但随着心算难度加大,大脑一侧化程度下降,而年老加剧了这一趋势;（3）青年组进行简单心算（1000—3）时,额中回未见明显激活,而老年组进行简单心算时,该脑区被明显激活。总体上,额叶和顶叶在心算活动中起着重要作用,而任务难度和年龄对心算加工时脑活动的影响以额中回区最为明显。     

The role of body image and self‐perception in anorexia nervosa: the neuroimaging perspective

Anorexia nervosa is a severe psychiatric illness characterized by intense fear of gaining weight, relentless pursuit of thinness, deep concerns about food and a pervasive disturbance of body image. Functional magnetic resonance imaging tries to shed light on the neurobiological underpinnings of anorexia nervosa. This review aims to evaluate the empirical neuroimaging literature about self‐perception in anorexia nervosa. This narrative review summarizes a number of task‐based and resting‐state functional magnetic resonance imaging studies in anorexia nervosa about body image and self‐perception. The articles listed in references were searched using electronic databases (PubMed and Google Scholar) from 1990 to February 2016 using specific key words. All studies were reviewed with regard to their quality and eligibility for the review. Differences in brain activity were observed using body image perception and body size estimation tasks showing significant modifications in activity of specific brain areas (extrastriate body area, fusiform body area, inferior parietal lobule). Recent studies highlighted the role of emotions and self‐perception in anorexia nervosa and their neural substrate involving resting‐state networks and particularly frontal and posterior midline cortical structures within default mode network and insula. These findings open new horizons to understand the neural substrate of anorexia nervosa.     

Specific and nonspecific thalamocortical functional connectivity in normal and vegetative states

Recent theoretical advances describing consciousness from information and integration have highlighted the unique role of the thalamocortical system in leading to integrated information and thus, consciousness. Here, we examined the differential distributions of specific and nonspecific thalamocortical functional connections using resting-state fMRI in a group of healthy subjects and vegetative-state patients. We found that both thalamic systems were widely distributed, but they exhibited different patterns. Nonspecific connections were preferentially associated with brain regions involved in higher-order cognitive processing, self-awareness and introspective mentalizing (e.g., the dorsal prefrontal and anterior cingulate cortices). In contrast, specific connections were prevalent in the ventral and posterior part of the prefrontal and precuneus, known involved in representing externally-directed attentions. Significant reductions of functional connectivity in both systems, especially the nonspecific system, were observed in VS. These data suggest that brain networks sustaining information and integration may be differentiated by the nature of their thalamic functional connectivity.     

从使动句加工的功能性磁共振成像看中文句法加工的独立性

大脑中的句法加工模式是神经认知科学研究的重要课题, 而句法加工是否存在独立性一直是研究者争论较多的问题。有形态标记的英语等印欧语语言的句法可以通过形态变化表现, 而汉语不具备与印欧语有明确对应关系的形态变化, 因此汉语的句法变化几乎不能通过外在形态标记。通过3T场强功能性磁共振成像, 以汉语语义等值使动句为研究材料, 对不依赖形态变化来标记句法变化的汉语句法加工的独立性进行了初步研究。结果显示, 大脑左侧额叶对于汉语句法加工具有重要的作用, 尤其是大脑左侧额叶中回的BA44区和额叶下回的BA47区都对汉语句法加工较为敏感, 这表明即使不通过形态改变来标记句法变化, 汉语句子加工中的句法加工仍然可以被分离, 句法独立性的加工主要由大脑左侧额叶中回及大脑左侧额叶下回等脑区承担, 大脑左侧颞叶并未参与汉语句法的独立性加工。     

人格特质及脑功能连接对社交网络的影响

采用网络分析的方法, 本研究从个体受欢迎程度和个体间亲密程度两方面探究了人格特质对社交网络的影响, 并在此基础上进一步探究了个体间大脑静息态功能连接相似性和社交网络的关系。结果发现：(1)高尽责性的个体在需要“值得信任”特质的社交网络中更受欢迎, 高宜人性的个体在需要“共享时光”的社交网络中更受欢迎; (2)在需要“相同兴趣”特质的社交网络中, 个体间人格相似性和社会距离呈显著负相关关系; (3)同样在需要“相同兴趣”特质的社交网络中, 个体间部分功能连接相似性与社会距离呈显著负相关关系, 这些功能连接主要集中在额顶控制网络以及背侧注意网络; 同时, 部分节点功能连接相似性与社会距离呈显著正相关关系, 这些功能连接主要集中在默认网络。研究结果揭示了人格特质对不同社交网络结构的影响, 以及个体间人格特质相似性和静息态脑网络相似性与社会距离的关系。本研究对理解社交网络的结构, 形成规律以及其中的信息传播规律有着重要启示意义。     

The relative contributions of subjective and objective measures of body shape and size to body image and disordered eating in women

This research explored the relative contributions of subjective perceptions of body weight and body shape/proportion, as well as objective measures of body mass index (BMI) and waist-to-hip ratio (WHR) to disordered eating, exercise involvement, and body image. One hundred and fifty-eight female university students completed questionnaires and provided body measurements for this study. Although an interaction between BMI and WHR was found for some measures (i.e., Eating Disorder Examination Questionnaire total and subscale scores), results indicated that BMI was consistently the better objective predictor of disordered eating and body image. Subjective perceptions of body weight and, to a lesser extent, body shape, were found to account for the greatest proportion of variance in the dependent measures (disordered eating, body esteem, and body dissatisfaction). Overall, these results offer more support for sociocultural theories emphasizing the importance of thinness for women, than evolutionary theories emphasizing the role of WHR.     

Event-related fMRI of category learning: differences in classification and feedback networks

Eighteen healthy young adults underwent event-related (ER) functional magnetic resonance imaging (fMRI) of the brain while performing a visual category learning task. The specific category learning task required subjects to extract the rules that guide classification of quasi-random patterns of dots into categories. Following each classification choice, visual feedback was presented. The average hemodynamic response was calculated across the eighteen subjects to identify the separate networks associated with both classification and feedback. Random-effects analyses identified the different networks implicated during the classification and feedback phases of each trial. The regions included prefrontal cortex, frontal eye fields, supplementary motor and eye fields, thalamus, caudate, superior and inferior parietal lobules, and areas within visual cortex. The differences between classification and feedback were identified as (i) overall higher volumes and signal intensities during classification as compared to feedback, (ii) involvement of the thalamus and superior parietal regions during the classification phase of each trial, and (iii) differential involvement of the caudate head during feedback. The effects of learning were then evaluated for both classification and feedback. Early in learning, subjects showed increased activation in the hippocampal regions during classification and activation in the heads of the caudate nuclei during the corresponding feedback phases. The findings suggest that early stages of prototype-distortion learning are characterized by networks previously associated with strategies of explicit memory and hypothesis testing. However as learning progresses the networks change. This finding suggests that the cognitive strategies also change during prototype-distortion learning.     

计算模型视角下信任形成的心理和神经机制——基于信任博弈中投资者的角度

人际信任渗透在社会交互的各个方面, 是促进和维持合作的重要基石。以往研究者借助信任博弈范式, 主要探讨了人际信任的理论模型、生物基础和影响因素等方面。近年来, 研究者开始将计算模型应用于信任博弈的数据分析中, 深入挖掘人际信任行为背后的心理机制, 将计算模型与神经影像技术结合, 加深对信任行为背后脑机制的理解。目前将计算模型应用于信任博弈范式中的研究主要针对“信任是如何形成的”这一科学问题, 未来要进一步发展计算模型方法, 结合非侵入性脑刺激技术, 应用于精神疾病人群中, 以深入理解正常和异常信任形成的心理和神经机制。     

The effects of seizures on the connectivity and circuitry of the developing brain

Recurring seizures in infants and children are often associated with cognitive deficits, but the reason for the learning difficulties is unclear. Recent studies in several animal models suggest that seizures themselves may contribute in important ways to these deficits. Other studies in animals have shown that recurring seizures result in dendritic spine loss. This change, coupled with a down-regulation in NMDA receptor subunit expression, suggests that repetitive seizures may interrupt the normal development of glutamatergic synaptic transmission. We hypothesize that homeostatic, neuroprotective processes are induced by recurring early-life seizures. These processes, by diminishing glutamatergic synaptic transmission, are aimed at preventing the continuation of seizures. However, by preventing the normal development of glutamatergic synapses, and particularly NMDA receptor-mediated synaptic transmission, such homeostatic processes also reduce synaptic plasticity and diminish the ability of neuronal circuits to learn and store memories.     

Effects of a 6-week aerobic dance intervention on body image and physical self-perceptions in adolescent girls

Research examining the impact of physical activity on body image dissatisfaction and physical self-perceptions has been both limited and equivocal. The current research investigated the effects of 6-week aerobic dance on these variables with 50 British schoolgirls aged 13–14 years. A cross-over design was used with two equivalent groups taught normal physical education and aerobic dance in a different order. The Body Attitude Questionnaire (BAQ) and Children and Youth Physical Self-Perception Profile (CY-PSPP) were administered as pre, mid and post-test to each participant in each group before the first intervention, at the change over and after 12 weeks. The results of this study revealed that participation in 6 weeks of aerobic dance significantly reduced body image dissatisfaction (Attractiveness, Feeling Fat, Salience and Strength and Fitness) and enhanced physical self-perceptions (Body Attractiveness and Physical Self-Worth), although these improvements were not sustained. The implications and future research directions are discussed.     

The effects of exposure to feminist ideology on women's body image

Body image disturbance has become a common problem among women and there is a need to focus on creating empirically supported treatments. Psychoeducational interventions have reduced body image dissatisfaction, but their impact is limited because they do not offer women adaptive methods of interpreting the many appearance-related messages they receive. This study examined if exposure to a feminist perspective may provide alternative interpretations of cultural messages, thereby increasing body image satisfaction. Participants were randomly assigned to a feminist or psychoeducational intervention, or a control group. Exposure to the feminist condition resulted in increased self-identification as a feminist and greater appearance satisfaction, and changes in feminist identity were related to positive changes in body image. The findings indicate that exposure to feminist theories may serve as an effective intervention strategy.     

认知判断中手部动作模拟的fMRI研究

该研究采用功能磁共振成像技术,考察不同条件下进行工具认知判断时手部姿势对认知判断的影响及动作模拟的神经机制。实验发现：手部姿势存在显著的主效应,冲突手部姿势条件下反应时最慢,且冲突手部姿势条件下与不冲突手部姿势条件下、自然状态条件下反应时存在显著差异,自然状态条件与不冲突手部姿势条件下反应时不存在显著差异。另外,f MRI成像结果发现,额中回、额下回、顶下小叶以及辅助运动区在自然状态下有显著激活,表明个体在进行认知判断过程中有动作模拟过程;海马结构、扣带回及楔前叶等与记忆有关的脑区有显著激活,表明身体经验在认知过程的作用。总的研究表明,不同的手部姿势状态对认知判断有不同影响,冲突手部姿势会对动作模拟产生干扰作用,手部动作模拟的神经机制主要涉及镜像神经元区,且在认知判断时存在具身效应。