fMRI

功能磁共振成像
  • 文章类型: Journal Article
    Traditionally, two fundamentally different theoretical approaches have been used in emotion research to model (human) emotions: discrete emotion theories and dimensional approaches. More recent neurophysiological models like the hierarchical emotion theory suggest that both should be integrated. The aim of this review is to provide neurocognitive evidence for this perspective with a particular focus on experimental studies manipulating anxiety and/or curiosity. We searched for evidence that the neuronal correlates of discrete and dimensional emotional systems are tightly connected. Our review suggests that the ACC (anterior cingulate cortex) responds to both, anxiety, and curiosity. While amygdala activation has been primarily observed for anxiety, at least the NAcc (nucleus accumbens) responds to both, anxiety and curiosity. When these two areas closely collaborate, as indicated by strong connectivity, this may indicate emotion regulation, particularly when the situation is not predictable.
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  • 文章类型: Journal Article
    Schizophrenia, as a chronic and persistent disorder, exhibits working memory deficits across various stages of the disorder, yet the neural mechanisms underlying these deficits remain elusive with inconsistent neuroimaging findings. We aimed to compare the brain functional changes of working memory in patients at different stages: clinical high risk, first-episode psychosis, and long-term schizophrenia, using meta-analyses of functional magnetic resonance imaging studies. Following a systematic literature search, 56 whole-brain task-based functional magnetic resonance imaging studies (15 for clinical high risk, 16 for first-episode psychosis, and 25 for long-term schizophrenia) were included. The separate and pooled neurofunctional mechanisms among clinical high risk, first-episode psychosis, and long-term schizophrenia were generated by Seed-based d Mapping toolbox. The clinical high risk and first-episode psychosis groups exhibited overlapping hypoactivation in the right inferior parietal lobule, right middle frontal gyrus, and left superior parietal lobule, indicating key lesion sites in the early phase of schizophrenia. Individuals with first-episode psychosis showed lower activation in left inferior parietal lobule than those with long-term schizophrenia, reflecting a possible recovery process or more neural inefficiency. We concluded that SCZ represent as a continuum in the early stage of illness progression, while the neural bases are inversely changed with the development of illness course to long-term course.
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  • 文章类型: Journal Article
    Despite over two decades of neuroimaging research, a unanimous definition of the pattern of structural variation associated with autism spectrum disorder (ASD) has yet to be found. One potential impeding issue could be the sometimes ambiguous use of measurements of variations in gray matter volumes (GMV) or gray matter concentrations (GMC). In fact, while both can be calculated using voxel-based morphometry analysis, these may reflect different underlying pathological mechanisms. We conducted a coordinate-based meta-analysis, keeping apart GMV and GMC studies of subjects with ASD. Results showed distinct and non-overlapping patterns for the two measures. GMV decreases were evident in the cerebellum, while GMC decreases were mainly found in the temporal and frontal regions. GMV increases were found in the parietal, temporal, and frontal brain regions, while GMC increases were observed in the anterior cingulate cortex and middle frontal gyrus. Age-stratified analyses suggested that such variations are dynamic across the ASD lifespan. The present findings emphasize the importance of considering GMV and GMC as distinct yet synergistic indices in autism research.
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  • 文章类型: Journal Article
    阿尔茨海默病(AD)是一种具有挑战性的神经退行性疾病,需要早期诊断和干预。这项研究利用了机器学习(ML)和图论指标,从静息态功能磁共振成像(rs-fMRI)数据中得出预测AD的数据。使用西南大学成人寿命数据集(SALD,年龄21-76岁)和开放获取系列成像研究(OASIS,年龄64-95岁)数据集,包含112名参与者,开发了各种ML模型用于AD预测。该研究确定了全面了解AD中脑网络拓扑和功能连通性的关键特征。通过5倍交叉验证,所有模型都表现出相当大的预测能力(准确率在82-92%范围内),支持向量机模型作为最佳模型,准确率为92%。目前的研究表明,前13个地区,基于最重要的区分特征识别,与丘脑失去了重要的联系.黑质的功能连接强度持续下降,网状结构,黑质,parscompacta,与健康成年人和衰老个体相比,AD受试者中的伏隔核。目前的发现证实了早期的研究,采用各种神经成像技术。这项研究标志着整合ML的综合方法的转化潜力,图论和rs-fMRI分析在AD预测中的应用,为AD的更准确诊断和早期预测提供潜在的生物标志物。
    Alzheimer\'s disease (AD) is a challenging neurodegenerative condition, necessitating early diagnosis and intervention. This research leverages machine learning (ML) and graph theory metrics, derived from resting-state functional magnetic resonance imaging (rs-fMRI) data to predict AD. Using Southwest University Adult Lifespan Dataset (SALD, age 21-76 years) and the Open Access Series of Imaging Studies (OASIS, age 64-95 years) dataset, containing 112 participants, various ML models were developed for the purpose of AD prediction. The study identifies key features for a comprehensive understanding of brain network topology and functional connectivity in AD. Through a 5-fold cross-validation, all models demonstrate substantial predictive capabilities (accuracy in 82-92% range), with the support vector machine model standing out as the best having an accuracy of 92%. Present study suggests that top 13 regions, identified based on most important discriminating features, have lost significant connections with thalamus. The functional connection strengths were consistently declined for substantia nigra, pars reticulata, substantia nigra, pars compacta, and nucleus accumbens among AD subjects as compared to healthy adults and aging individuals. The present finding corroborate with the earlier studies, employing various neuroimagining techniques. This research signifies the translational potential of a comprehensive approach integrating ML, graph theory and rs-fMRI analysis in AD prediction, offering potential biomarker for more accurate diagnostics and early prediction of AD.
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  • 文章类型: Journal Article
    生命早期接触环境污染物与青少年抑郁症患病率和严重程度的增加有关;然而,这种关联的神经生物学机制尚不清楚.在目前的纵向研究中,我们调查了青春期早期(9~13岁)的污染负担是否与内隐情绪调节期间的脑激活和脑连接改变以及整个青春期抑郁症状的变化有关.
    一百四十五名参与者(n=87名女性;9-13岁)提供了住址,从中我们确定了它们在人口普查区的相对污染负担,并在扫描仪中执行隐式情感调节任务。参与者还完成了3个时间点的抑郁症状评估问卷,每隔大约2年,从中我们计算了人内抑郁症状的斜率。我们进行了全脑激活和连通性分析,以检查在积极和消极刺激的内隐情绪调节期间,污染负担是否与脑功能改变有关,以及这些影响如何与青春期抑郁症状的斜率有关。
    更大的污染负担与更大的双侧内侧前额叶皮层激活和更强的双侧内侧前额叶皮层与默认模式网络内区域的连通性有关(例如,颞顶交界处,后扣带皮质,precuneus)在负面情绪的内隐调节期间,在暴露于较高污染负担的人群中,这与青春期抑郁症状的增加有关。
    生活在污染负担较大的社区中的青少年在负面情绪的内隐调节过程中表现出改变的默认模式网络功能,这与青春期抑郁症状的增加有关。
    暴露于环境污染与青少年患抑郁症的风险增加有关;然而,这种关联的神经生物学机制尚不清楚.我们发现,在负面情绪的内隐调节过程中,生活在人口普查道污染负担较高的社区中的青少年在内侧前额叶皮层和默认模式网络内的区域之间具有更强的功能连通性,这反过来又与这些暴露于污染的年轻人的青春期抑郁症状增加有关。
    UNASSIGNED: Exposure to environmental pollutants early in life has been associated with increased prevalence and severity of depression in adolescents; however, the neurobiological mechanisms underlying this association are not well understood. In the current longitudinal study, we investigated whether pollution burden in early adolescence (9-13 years) was associated with altered brain activation and connectivity during implicit emotion regulation and changes in depressive symptoms across adolescence.
    UNASSIGNED: One hundred forty-five participants (n = 87 female; 9-13 years) provided residential addresses, from which we determined their relative pollution burden at the census tract level, and performed an implicit affective regulation task in the scanner. Participants also completed questionnaires assessing depressive symptoms at 3 time points, each approximately 2 years apart, from which we calculated within-person slopes of depressive symptoms. We conducted whole-brain activation and connectivity analyses to examine whether pollution burden was associated with alterations in brain function during implicit emotion regulation of positively and negatively valenced stimuli and how these effects were related to slopes of depressive symptoms across adolescence.
    UNASSIGNED: Greater pollution burden was associated with greater bilateral medial prefrontal cortex activation and stronger bilateral medial prefrontal cortex connectivity with regions within the default mode network (e.g., temporoparietal junction, posterior cingulate cortex, precuneus) during implicit regulation of negative emotions, which was associated with greater increases in depressive symptoms across adolescence in those exposed to higher pollution burden.
    UNASSIGNED: Adolescents living in communities characterized by greater pollution burden showed altered default mode network functioning during implicit regulation of negative emotions that was associated with increases in depressive symptoms across adolescence.
    Exposure to environmental pollution is related to increased risk for depression in youth; however, the neurobiological mechanisms underlying this association are unknown. We found that adolescents living in neighborhoods with greater census tract–level pollution burden had stronger functional connectivity between the medial prefrontal cortex and regions within the default mode network during implicit regulation of negative emotions, which in turn was associated with greater increases in depressive symptoms across adolescence in these pollution-exposed youths.
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  • 文章类型: Journal Article
    音乐是影响我们的情感和记忆的强大媒介。神经科学研究已经证明了音乐能够参与与情绪相关的大脑区域,奖励,动机,和自传记忆。虽然音乐在调节情绪中的作用已经得到了广泛的探索,我们的研究调查音乐是否可以改变记忆的情感内容。建立在记忆可以在检索时更新的理论上,我们测试了在记忆回忆中引入情感音乐是否会在原始记忆痕迹中引入虚假的情感元素。我们开发了一个单独编码的3天情景记忆任务,回忆,和检索阶段。我们的主要假设是,在记忆回忆过程中播放的情感音乐会增加将新颖的情感成分引入原始记忆的可能性。行为发现揭示了两个关键结果:1)在记忆回忆过程中接触音乐的参与者更有可能融入与配对音乐效价一致的新颖情感成分,和2)1天后检索的记忆表现出比原始记忆更强的情感基调,与前一天的回忆中配对的音乐的效价一致。此外,功能磁共振成像结果显示,在用音乐回忆故事的过程中,神经参与发生了变化,包括杏仁核,前海马,和下顶叶小叶。杏仁核和其他大脑区域之间的连接增强,包括额叶和视觉皮层,在回忆音乐时被观察到,可能有助于更情绪化的故事重建。这些发现阐明了音乐之间的相互作用,情感,和记忆,提供对将情感音乐注入记忆回忆过程的后果的见解。
    Music is a powerful medium that influences our emotions and memories. Neuroscience research has demonstrated music\'s ability to engage brain regions associated with emotion, reward, motivation, and autobiographical memory. While music\'s role in modulating emotions has been explored extensively, our study investigates whether music can alter the emotional content of memories. Building on the theory that memories can be updated upon retrieval, we tested whether introducing emotional music during memory recollection might introduce false emotional elements into the original memory trace. We developed a 3-day episodic memory task with separate encoding, recollection, and retrieval phases. Our primary hypothesis was that emotional music played during memory recollection would increase the likelihood of introducing novel emotional components into the original memory. Behavioral findings revealed two key outcomes: 1) participants exposed to music during memory recollection were more likely to incorporate novel emotional components congruent with the paired music valence, and 2) memories retrieved 1 day later exhibited a stronger emotional tone than the original memory, congruent with the valence of the music paired during the previous day\'s recollection. Furthermore, fMRI results revealed altered neural engagement during story recollection with music, including the amygdala, anterior hippocampus, and inferior parietal lobule. Enhanced connectivity between the amygdala and other brain regions, including the frontal and visual cortex, was observed during recollection with music, potentially contributing to more emotionally charged story reconstructions. These findings illuminate the interplay between music, emotion, and memory, offering insights into the consequences of infusing emotional music into memory recollection processes.
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  • 文章类型: Journal Article
    大脑如何处理熟悉的人的面孔?神经心理学研究认为,颞极(TP)区域将面孔与人的身份联系起来,但是该区域的磁化率伪影阻碍了fMRI的研究。使用优化的数据采集和分析方法来克服这种伪影,我们在TP中识别出熟悉的面部反应,在个体大脑中可靠地观察到。这个区域对熟悉面孔的视觉图像比陌生面孔反应强烈,对象,和场景。然而,TP不仅对面部图像做出反应,而且还涉及各种高级社会认知任务,包括语义,情节,和心理任务理论。TP的响应曲线与周围皮层的附近区域形成对比,该区域专门对面部做出响应,但不是社会认知任务。TP在功能上与与社会认知相关的关联皮层中的分布式网络相连,而PR在功能上与腹侧视觉皮层的面部偏爱区域有关。这项工作确定了人脸处理系统中缺少的一个环节,该环节专门处理熟悉的面孔,并且可以很好地将有关面部的视觉信息与有关其他人的高阶概念信息集成在一起。结果表明,用于人和面部处理的单独流到达位于皮质层次结构顶部的前颞区。
    How does the brain process the faces of familiar people? Neuropsychological studies have argued for an area of the temporal pole (TP) linking faces with person identities, but magnetic susceptibility artifacts in this region have hampered its study with fMRI. Using data acquisition and analysis methods optimized to overcome this artifact, we identify a familiar face response in TP, reliably observed in individual brains. This area responds strongly to visual images of familiar faces over unfamiliar faces, objects, and scenes. However, TP did not just respond to images of faces, but also to a variety of high-level social cognitive tasks, including semantic, episodic, and theory of mind tasks. The response profile of TP contrasted with a nearby region of the perirhinal cortex that responded specifically to faces, but not to social cognition tasks. TP was functionally connected with a distributed network in the association cortex associated with social cognition, while PR was functionally connected with face-preferring areas of the ventral visual cortex. This work identifies a missing link in the human face processing system that specifically processes familiar faces, and is well placed to integrate visual information about faces with higher-order conceptual information about other people. The results suggest that separate streams for person and face processing reach anterior temporal areas positioned at the top of the cortical hierarchy.
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  • 文章类型: Journal Article
    目标:暴食症(BED)成人,与那些没有床的人相比,在大脑的奖励相关区域显示出较高的血氧水平依赖性(BOLD)对食物提示的反应。尚不清楚认知行为疗法(CBT)是否可以逆转这种奖励系统的过度激活。这项随机对照试验(RCT)评估了CBT与等待列表对照(WLC)后对暴饮暴食线索的BOLD反应的变化。
    方法:将患有BED的女性(N=40)随机分为CBT或WLC。参与者在基线和16周时完成评估,包括饮食和食欲的测量以及功能磁共振成像(fMRI)以测量BOLD反应,同时聆听暴饮暴食和中性放松线索的个性化脚本。使用具有混合效应的一般线性模型分析数据。
    结果:总保留率为87.5%。与WLC相比,CBT在暴饮暴食发作方面的减少幅度明显更大(平均值±标准误差下降14.6±2.7与过去28天5.7±2.8发作,分别为;p=0.03)。在fMRI过程中,CBT和WLC对暴饮暴食刺激的神经反应变化没有显着差异。与WLC相比,CBT在基于奖励的饮食驱动方面有了更大的改进,去抑制,和通过问卷评估的饥饿(ps<0.05)。
    结论:CBT可有效减少暴饮暴食,但是,与我们的假设相反,CBT并不能改善大脑奖励区域对听觉暴饮暴食刺激的BOLD反应。需要进一步的研究来评估BEDCBT改善的潜在机制。
    背景:ClinicalTrials.gov标识符:NCT03604172。
    OBJECTIVE: Adults with binge-eating disorder (BED), compared with those without BED, demonstrate higher blood-oxygen-level-dependent (BOLD) response to food cues in reward-related regions of the brain. It is not known whether cognitive behavioral therapy (CBT) can reverse this reward system hyperactivation. This randomized controlled trial (RCT) assessed changes in BOLD response to binge-eating cues following CBT versus wait-list control (WLC).
    METHODS: Females with BED (N = 40) were randomized to CBT or WLC. Participants completed assessments at baseline and 16 weeks including measures of eating and appetite and functional magnetic resonance imaging (fMRI) to measure BOLD response while listening to personalized scripts of binge-eating and neutral-relaxing cues. Data were analyzed using general linear models with mixed effects.
    RESULTS: Overall retention rate was 87.5%. CBT achieved significantly greater reductions in binge-eating episodes than WLC (mean ± standard error decline of 14.6 ± 2.7 vs. 5.7 ± 2.8 episodes in the past 28 days, respectively; p = 0.03). CBT and WLC did not differ significantly in changes in neural responses to binge-eating stimuli during the fMRI sessions. Compared with WLC, CBT had significantly greater improvements in reward-based eating drive, disinhibition, and hunger as assessed by questionnaires (ps < 0.05).
    CONCLUSIONS: CBT was effective in reducing binge eating, but, contrary to our hypothesis, CBT did not improve BOLD response to auditory binge-eating stimuli in reward regions of the brain. Further studies are needed to assess mechanisms underlying improvements with CBT for BED.
    BACKGROUND: ClinicalTrials.gov identifier: NCT03604172.
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  • 文章类型: Journal Article
    沉思神经科学越来越多地使用神经成像探索冥想。然而,冥想背后的大脑机制仍然难以捉摸。这里,我们实施了一个机制框架来探索冥想和休息期间专家冥想者的时空动力学,和休息时的控制。我们首先通过为每个条件定义概率亚稳态(PMS)空间来应用无模型方法,由一系列动态模式的不同发生概率组成。此外,我们通过将每个条件的PMS调整为全脑模型来实现基于模型的方法,这使我们能够在计算机扰动中探索从静息状态到冥想的过渡,反之亦然。因此,我们评估了不同脑区的扰动性和局部-全局机制效应的敏感性.总的来说,与休息相比,我们的工作揭示了冥想中独特的全脑动态,以及局部人工扰动如何诱导跃迁。它激发了未来的工作,将冥想作为一种健康实践,并作为脑部疾病的潜在疗法。
    我们的工作探索了一组专家冥想者和控制者的大脑动力学。首先,我们用一系列大脑模式来描述冥想和休息,每个都有其不同的发生概率。然后,我们生成了每种情况的全脑模型,这使我们能够人为地干扰系统,以引起休息和冥想之间的过渡。我们的研究结果为冥想研究开辟了新的途径,作为健康和疾病的实践。
    Contemplative neuroscience has increasingly explored meditation using neuroimaging. However, the brain mechanisms underlying meditation remain elusive. Here, we implemented a mechanistic framework to explore the spatiotemporal dynamics of expert meditators during meditation and rest, and controls during rest. We first applied a model-free approach by defining a probabilistic metastable substate (PMS) space for each condition, consisting of different probabilities of occurrence from a repertoire of dynamic patterns. Moreover, we implemented a model-based approach by adjusting the PMS of each condition to a whole-brain model, which enabled us to explore in silico perturbations to transition from resting-state to meditation and vice versa. Consequently, we assessed the sensitivity of different brain areas regarding their perturbability and their mechanistic local-global effects. Overall, our work reveals distinct whole-brain dynamics in meditation compared to rest, and how transitions can be induced with localized artificial perturbations. It motivates future work regarding meditation as a practice in health and as a potential therapy for brain disorders.
    Our work explores brain dynamics in a group of expert meditators and controls. First, we characterized meditation and rest with a repertoire of brain patterns, each with its distinct probability of occurrence. Then, we generated whole-brain models of each condition, which enabled us to artificially perturb the systems to induce transitions between rest and meditation. Our results open new avenues in meditation research as a practice in health and disease.
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  • 文章类型: Journal Article
    脑动力学可以被建模为从功能磁共振成像(fMRI)信号中的不同脑区域的活动开始的时间脑网络。当验证关于时间网络的假设时,重要的是使用一个适当的统计空模型,与处理过的经验数据共享一些特征。这项工作的目的是通过引入随机时间双曲(RTH)图模型来为脑网络的时间零模型理论做出贡献,随机双曲(RH)图的扩展,在复杂网络研究中,以其重现现实世界网络关键属性的能力而闻名。我们专注于时间小世界,在静态情况下,已经在现实世界的复杂网络中进行了广泛的研究,并且与大脑网络有效交换信息的能力有关。我们将RTH图模型与时间网络的标准空模型进行了比较,并表明空模型最能再现静息大脑活动的小世界性。这种重现真实大脑网络基本特征的能力,与经典模型相比,只添加了一个参数,表明RTH图模型是验证有关时间脑网络假设的有前途的工具。
    我们表明,随机时间双曲(RTH)图是一个合适的零模型,用于测试有关大脑动力学的假设,在将其与当前的最新状态和其他两个几何零模型进行比较之后。这个理论模型的静态版本捕获了各种现实世界网络的属性,它的时间版本展示了时间小世界的属性,为此,我们提出了一个新的适当的时间定义。特别是,我们表明,该模型最好地再现了从fMRI信号中提取的经验时间网络中测量的时间小世界性。
    Brain dynamics can be modeled as a temporal brain network starting from the activity of different brain regions in functional magnetic resonance imaging (fMRI) signals. When validating hypotheses about temporal networks, it is important to use an appropriate statistical null model that shares some features with the treated empirical data. The purpose of this work is to contribute to the theory of temporal null models for brain networks by introducing the random temporal hyperbolic (RTH) graph model, an extension of the random hyperbolic (RH) graph, known in the study of complex networks for its ability to reproduce crucial properties of real-world networks. We focus on temporal small-worldness which, in the static case, has been extensively studied in real-world complex networks and has been linked to the ability of brain networks to efficiently exchange information. We compare the RTH graph model with standard null models for temporal networks and show it is the null model that best reproduces the small-worldness of resting brain activity. This ability to reproduce fundamental features of real brain networks, while adding only a single parameter compared with classical models, suggests that the RTH graph model is a promising tool for validating hypotheses about temporal brain networks.
    We show that the random temporal hyperbolic (RTH) graph is a suitable null model for testing hypotheses about brain dynamics, after comparing it with the current state of the art and two other geometric null models. The static version of this theoretical model captures properties of various real-world networks, and its temporal version exhibits the temporal small-world property, for which we propose a new proper temporal definition. In particular, we show that the model best reproduces the temporal small-worldness measured in the empirical temporal network extracted from fMRI signals.
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