fMRI

功能磁共振成像
  • 文章类型: Case Reports
    原发性脑肿瘤与死亡率和发病率升高相关。脑肿瘤手术旨在实现最大程度的肿瘤切除,同时最大程度地减少对健康脑组织的损害。神经调节诱导的皮质前康复(NICP)的研究突出了这一潜力,在神经外科手术之前,建立新的大脑连接并将功能活动从大脑的一个区域转移到另一个区域。尽管如此,这些过程背后的神经机制,特别是在占位性病变的背景下,仍然不清楚。患有左额孢子囊肿瘤的患者接受了一项康复治疗方案,该方案通过语言网络提供20次抑制性非侵入性神经调节(rTMS和多通道tDCS),并进行了强化任务训练。康复治疗导致肿瘤与语言网络之间的距离增加。此外,在语言电路内观察到增强的功能连通性。本创新的案例研究表明,对占位病变周围的功能网络区域的抑制促进了网络空间组织的可塑性变化,推测是通过建立远离病变部位的新型功能途径。虽然这些结果很有希望,谨慎性要求需要更大规模的研究来证实和推广这些发现。
    Primary brain neoplasms are associated with elevated mortality and morbidity rates. Brain tumour surgery aims to achieve maximal tumour resection while minimizing damage to healthy brain tissue. Research on Neuromodulation Induced Cortical Prehabilitation (NICP) has highlighted the potential, before neurosurgery, of establishing new brain connections and transfer functional activity from one area of the brain to another. Nonetheless, the neural mechanisms underlying these processes, particularly in the context of space-occupying lesions, remain unclear. A patient with a left frontotemporoinsular tumour underwent a prehabilitation protocol providing 20 sessions of inhibitory non-invasive neuromodulation (rTMS and multichannel tDCS) over a language network coupled with intensive task training. Prehabilitation resulted in an increment of the distance between the tumour and the language network. Furthermore, enhanced functional connectivity within the language circuit was observed. The present innovative case-study exposed that inhibition of the functional network area surrounding the space-occupying lesion promotes a plastic change in the network\'s spatial organization, presumably through the establishment of novel functional pathways away from the lesion\'s site. While these outcomes are promising, prudence dictates the need for larger studies to confirm and generalize these findings.
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  • 文章类型: Journal Article
    玛丽,由于缺血性中风而出现非流利的失语症,接受了10年的个性化语言培训(LT),导致言语和理解力的短暂增强。为了增强这些效果,她的LT方案中加入了多部位经颅直流电刺激(tDCS),共15次.使用可靠变化指数进行的评估表明,该组合改善了她的左下额叶连通性和言语产生两个月,并且在一个月后显着提高了理解力。结果表明,使用多部位经颅直流电刺激(tDCS)可以提高非流利失语症患者语言治疗(LT)的有效性。
    Mary, who experienced non-fluent aphasia as a result of an ischemic stroke, received 10 years of personalized language training (LT), resulting in transient enhancements in speech and comprehension. To enhance these effects, multisite transcranial Direct Current Stimulation (tDCS) was added to her LT regimen for 15 sessions. Assessment using the Reliable Change Index showed that this combination improved her left inferior frontal connectivity and speech production for two months and significantly improved comprehension after one month. The results indicate that using multisite transcranial direct current stimulation (tDCS) can improve the effectiveness of language therapy (LT) for individuals with non-fluent aphasia.
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  • 文章类型: Journal Article
    Steinkrauss和Slotnick(2024)回顾了将海马体与内隐记忆联系起来的神经影像学研究。他们得出的结论是,没有令人信服的证据表明海马体与内隐记忆有关,因为先前的研究被外显记忆(以及其他因素)所混淆。这里,我们提出了一个不同但同样重要的问题:无意识海马活动的报告是否反映了I型错误(即假阳性)?我们发现39%的将海马体与内隐记忆联系起来的研究(18个中的7个)没有报告多重比较的校正。这些结果表明,许多无意识的海马效应可能反映了I型错误。
    Steinkrauss and Slotnick (2024) reviewed neuroimaging studies linking the hippocampus with implicit memory. They conclude that there is no convincing evidence that the hippocampus is associated with implicit memory because prior studies are confounded by explicit memory (among other factors). Here, we ask a different yet equally important question: do reports of unconscious hippocampal activity reflect a Type-I error (i.e. a false positive)? We find that 39% of studies linking the hippocampus with implicit memory (7 of 18) do not report correcting for multiple comparisons. These results indicate that many unconscious hippocampal effects may reflect a Type-I error.
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  • 文章类型: Journal Article
    Logopenic变体原发性进行性失语症(lvPPA)的特征是流利的言语中的单词发现缺陷和语音错误。针对左颞顶交界处(TPJ)或左额下回(IFG)的经颅直流电刺激(tDCS)显示出改善lvPPA语言功能的证据。本案例研究评估了两轮单独的高清tDCS(HD-tDCS)(4mA;30次会议)对一名57岁患有lvPPA的女性的语言和功能神经影像学的影响。刺激集中在两个不同的区域:(1)左TPJ,和(2)左(IFG)。结果表明,在两轮自然语音任务中,内容与地板上的单词的比例都有所提高,并且在TPJ(改善)和IFG(恶化)刺激后,对抗命名发生了变化。任务过程中的fMRI连通性在第1轮之后显示出左侧的正相关,而在第2轮之后与默认模式网络的组件存在反相关。与语言相关的功能网络的静息状态隔离在两轮之后都有所增加,IFG刺激后,同一网络的基于任务的隔离增加。这些结果表明,使用HD-tDCS对两个区域的刺激可能会改善lvPPA的语言功能,同时在神经元活动和功能连接方面引起目标区域以外的广泛变化。
    Logopenic variant primary progressive aphasia (lvPPA) is characterized by word-finding deficits and phonologic errors in fluent speech. Transcranial direct current stimulation (tDCS) targeting either left temporoparietal junction (TPJ) or left inferior frontal gyrus (IFG) show evidence of improving language function in lvPPA. The present case study evaluated the effects of two separate rounds of high definition tDCS (HD-tDCS) (4 mA; 30 sessions) on language and functional neuroimaging in a 57-year-old woman with lvPPA. Stimulation was centred on two different regions across rounds: (1) left TPJ, and (2) left (IFG). Results showed an improved proportion of content to floorholder words during a naturalistic speech task through both rounds as well as change in confrontation naming after TPJ (improvement) and IFG (worsened) stimulation. fMRI connectivity during task showed left lateralized positive correlations following round 1 and anti-correlations with components of the default mode network following round 2. Resting state segregation of a language-associated functional network increased following both rounds, and task-based segregation of the same network increased following IFG stimulation. These results suggest that stimulation to both regions using HD-tDCS may improve language function in lvPPA, while simultaneously eliciting widespread changes beyond the targeted area in neuronal activity and functional connectivity.
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  • 文章类型: Journal Article
    大多数用于分析基于fMRI的功能连接(FC)和基因组数据的软件包都与编程语言接口一起使用,缺乏易于导航的GUI前端。这加剧了在这些类型的数据中发现的两个问题:面对高维度的特征,人口统计学混淆和质量控制。原因是使用编程接口来创建识别所有相关性所需的所有必要可视化内容太慢且麻烦,混杂效应,或数据集中的质量控制问题。特别是FC通常每个主题包含成千上万的功能,并且只能使用可视化进行总结和有效探索。为了纠正这种情况,我们开发了ImageNomer,一种数据可视化和分析工具,可以检查受试者水平和队列水平的人口统计,基因组,和成像功能。该软件是基于Python的,在独立的Docker映像中运行,并包含基于浏览器的GUI前端。我们通过在费城神经发育队列(PNC)数据集中预测成就分数时识别意外的种族混淆来证明ImageNomer的有用性,其中包含健康青少年的多任务fMRI和单核苷酸多态性(SNP)数据。在过去,许多研究尝试使用FC来识别功能磁共振成像中与成就相关的特征.使用ImageNomer可视化种族之间成就得分的趋势,如果可以使用FC预测种族,我们发现明显的混淆效应潜力。使用ImageNomer软件中的相关性分析,我们表明,与广泛成就测试(WRAT)得分相关的FC实际上与种族高度相关。进一步调查,我们发现,尽管FC和SNP(基因组)特征都可以占WRAT评分变异的10-15%,当控制种族时,这种预测能力就消失了。我们还使用ImageNomer来研究双相和精神分裂症中间表型网络(BSNIP)数据集中的种族-FC相关性。在这项工作中,我们展示了ImageNomerGUI工具在数据探索和混淆检测方面的优势.此外,这项工作将种族认定为FC数据中的一个强混淆因素,并对在健康青少年的fMRI和SNP数据中发现与成就相关的无偏见特征的可能性产生怀疑.
    Most packages for the analysis of fMRI-based functional connectivity (FC) and genomic data are used with a programming language interface, lacking an easy-to-navigate GUI frontend. This exacerbates two problems found in these types of data: demographic confounds and quality control in the face of high dimensionality of features. The reason is that it is too slow and cumbersome to use a programming interface to create all the necessary visualizations required to identify all correlations, confounding effects, or quality control problems in a dataset. FC in particular usually contains tens of thousands of features per subject, and can only be summarized and efficiently explored using visualizations. To remedy this situation, we have developed ImageNomer, a data visualization and analysis tool that allows inspection of both subject-level and cohort-level demographic, genomic, and imaging features. The software is Python-based, runs in a self-contained Docker image, and contains a browser-based GUI frontend. We demonstrate the usefulness of ImageNomer by identifying an unexpected race confound when predicting achievement scores in the Philadelphia Neurodevelopmental Cohort (PNC) dataset, which contains multitask fMRI and single nucleotide polymorphism (SNP) data of healthy adolescents. In the past, many studies have attempted to use FC to identify achievement-related features in fMRI. Using ImageNomer to visualize trends in achievement scores between races, we find a clear potential for confounding effects if race can be predicted using FC. Using correlation analysis in the ImageNomer software, we show that FCs correlated with Wide Range Achievement Test (WRAT) score are in fact more highly correlated with race. Investigating further, we find that whereas both FC and SNP (genomic) features can account for 10-15% of WRAT score variation, this predictive ability disappears when controlling for race. We also use ImageNomer to investigate race-FC correlation in the Bipolar and Schizophrenia Network for Intermediate Phenotypes (BSNIP) dataset. In this work, we demonstrate the advantage of our ImageNomer GUI tool in data exploration and confound detection. Additionally, this work identifies race as a strong confound in FC data and casts doubt on the possibility of finding unbiased achievement-related features in fMRI and SNP data of healthy adolescents.
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  • 文章类型: Case Reports
    言语缺失是神经发育综合征的一种临床表型,为神经语言模型提供见解。我们介绍了一例双边perisylvianpolymicrogyria(BPP)和完全没有言语的情况,并且语言理解和生产困难相当大。我们通过采用多模态神经成像方法来广泛表征听觉语音感知和产生电路。结果显示运动和听觉语言区域的皮质广泛增厚。尽管丘脑投射相对保留,但听觉皮层对言语刺激缺乏敏感性,但没有内在的功能组织。在处理的早期阶段涉及的皮层下结构表现出对语音的敏感性提高。弓形束,BPP中建议的语言标记,显示与健康对照相似的体积和完整性。额叶倾斜的道,与oomotor功能相关,部分重建。这些发现强调了评估语音产生结构之外的听觉皮层以理解BPP中的语音缺失的重要性。尽管皮质发生了深刻的改变,内在的运动网络和运动-言语通路基本保持完整。该病例强调了使用多种MRI模式进行全面表型分析的必要性,以发现语言发育严重中断的原因。
    The absence of speech is a clinical phenotype seen across neurodevelopmental syndromes, offering insights for neural language models. We present a case of bilateral perisylvian polymicrogyria (BPP) and complete absence of speech with considerable language comprehension and production difficulties. We extensively characterized the auditory speech perception and production circuitry by employing a multimodal neuroimaging approach. Results showed extensive cortical thickening in motor and auditory-language regions. The auditory cortex lacked sensitivity to speech stimuli despite relatively preserved thalamic projections yet had no intrinsic functional organization. Subcortical structures implicated in early stages of processing exhibited heightened sensitivity to speech. The arcuate fasciculus, a suggested marker of language in BPP, showed similar volume and integrity to a healthy control. The frontal aslant tract, linked to oromotor function, was partially reconstructed. These findings highlight the importance of assessing the auditory cortex beyond speech production structures to understand absent speech in BPP. Despite profound cortical alterations, the intrinsic motor network and motor-speech pathways remained largely intact. This case underscores the need for comprehensive phenotyping using multiple MRI modalities to uncover causes of severe disruption in language development.
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  • 文章类型: Journal Article
    使用功能磁共振成像,从女性盲人受试者的常规活动中提取精确的时间控制。研究结果揭示了一种特定的神经机制,用于对情景记忆中的召回顺序事件进行时间控制。
    Using fMRI, precise temporal control was extracted from routine activities in a female blind subject. Findings reveal a specific neural machinery for temporal control of recalled sequential events in episodic memory.
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  • 文章类型: Case Reports
    日常生活活动(ADL)的损害是中风后康复的主要问题。上肢运动障碍,具体来说,与生活质量低有关。在目前的病例报告中,我们使用任务型和静息状态功能磁共振成像(fMRI)工具,研究了1例重度上肢运动障碍的慢性卒中后患者高压氧治疗(HBOT)诱导的运动康复的神经反应机制和功能重组.
    我们研究了一名61岁的右撇子男性患者的运动任务fMRI激活和静息状态功能连接(rsFC),该患者患有右上肢偏瘫和身体虚弱,在他受到严重侮辱两年后,每天60个HBOT疗程的治疗前后。在基线和治疗结束时使用Fugl-Meyer评估(FMA)和手握最大自主收缩(MVC)评估运动功能。
    遵循HBOT,FMA评分从17(严重损害)提高到31(中度损害)。在涉及受影响的手的试验期间进行干预后,在补充运动皮质(SMA)和运动前皮质(PMA)两侧观察到fMRI激活增加.侧化指数(LI)从1降至0.63,表明对侧半球的募集。感兴趣的区域,ROI到ROI,分析显示,干预后半球间连通性增加(P=0.002),网络间连通性增加(z评分:0.35±0.21~0.41±0.21,P<0.0001).使用右SMA作为种子的基于种子到体素的rsFC分析显示与左后顶叶皮层的连通性增加,左侧初级体感皮层,和运动前皮层。
    这项研究为慢性卒中后患者HBOT诱导的大脑可塑性和功能改善提供了更多见解。
    UNASSIGNED: Impairments in activities of daily living (ADL) are a major concern in post-stroke rehabilitation. Upper-limb motor impairments, specifically, have been correlated with low quality of life. In the current case report, we used both task-based and resting state functional MRI (fMRI) tools to investigate the neural response mechanisms and functional reorganization underlying hyperbaric oxygen therapy (HBOT)-induced motor rehabilitation in a chronic post-stroke patient suffering from severe upper-limb motor impairment.
    UNASSIGNED: We studied motor task fMRI activation and resting-state functional connectivity (rsFC) in a 61-year-old right-handed male patient who suffered hemiparesis and physical weakness in the right upper limb, 2 years after his acute insult, pre- and post-treatment of 60 daily HBOT sessions. Motor functions were assessed at baseline and at the end of the treatment using the Fugl-Meyer assessment (FMA) and the handgrip maximum voluntary contraction (MVC).
    UNASSIGNED: Following HBOT, the FMA score improved from 17 (severe impairment) to 31 (moderate impairment). Following the intervention during trials involving the affected hand, there was an observed increase in fMRI activation in both the supplementary motor cortex (SMA) and the premotor cortex (PMA) bilaterally. The lateralization index (LI) decreased from 1 to 0.63, demonstrating the recruitment of the contralesional hemisphere. The region of interest, ROI-to-ROI, analysis revealed increased post-intervention inter-hemispheric connectivity (P = 0.002) and a between-network connectivity increase (z-score: 0.35 ± 0.21 to 0.41 ± 0.21, P < 0.0001). Seed-to-voxel-based rsFC analysis using the right SMA as seed showed increased connectivity to the left posterior parietal cortex, the left primary somatosensory cortex, and the premotor cortex.
    UNASSIGNED: This study provides additional insights into HBOT-induced brain plasticity and functional improvement in chronic post-stroke patients.
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  • 文章类型: Journal Article
    思维空白(MB)被称为无法报告我们过去的心理内容。与具有可报告内容的精神状态相反,比如走神或感官知觉,MB的神经相关性最近才开始阐明。与MB研究有关的一个值得注意的特殊性是MB被指示报告的方式,比如故意要求参与者“清空他们的思想”。“这些指令被证明可以诱导额脑区域的fMRI激活,通常与元认知和自我评估过程相关,这表明MB可能是故意抑制精神内容的结果。这里,我们的目的是通过在没有诱导的情况下确定MB的神经相关性来检验这一假设。在31名参与者(22名女性)中使用功能磁共振成像结合经验抽样,MB报告的单变量分析显示枕骨失活,额叶,顶叶,和丘脑区,但前额区没有激活。通过对先前显示与诱导MB有关的区域进行贝叶斯感兴趣区域分析,证实了这些发现。与其他精神状态相比,我们在MB报告期间报告了额叶失活的证据。MB报告和面向内容的精神状态之间的对比分析也显示了左角回的失活。我们认为这些效应表征了MB的神经元谱,关键的丘脑皮质节点无法沟通和制定可报告的内容。总的来说,我们表明,MB的研究说明导致不同的神经激活。这些结果提供了与MB现象学相关的机械见解,并指出了MB以不同形式表达的可能性。本研究探讨了当个人报告无法识别的想法时,大脑活动如何变化,一种被称为思维消隐(MB)的现象。它旨在检测自发报告MB时大脑激活和失活的变化,与先前报道的MB诱导时的神经反应相反。通过脑成像和经验采样,这项研究指出许多区域的大脑活动减少,包括那些先前在诱导MB期间被检测为激活的mesio-frontally。这些结果增强了我们对自发思维复杂性的理解,并有助于对意识和可报告经验进行更广泛的讨论。
    Mind-blanking (MB) is termed as the inability to report our immediate-past mental content. In contrast to mental states with reportable content, such as mind-wandering or sensory perceptions, the neural correlates of MB started getting elucidated only recently. A notable particularity that pertains to MB studies is the way MB is instructed for reporting, like by deliberately asking participants to \"empty their minds.\" Such instructions were shown to induce fMRI activations in frontal brain regions, typically associated with metacognition and self-evaluative processes, suggesting that MB may be a result of intentional mental content suppression. Here, we aim at examining this hypothesis by determining the neural correlates of MB without induction. Using fMRI combined with experience-sampling in 31 participants (22 female), univariate analysis of MB reports revealed deactivations in occipital, frontal, parietal, and thalamic areas, but no activations in prefrontal regions. These findings were confirmed using Bayesian region-of-interest analysis on areas previously shown to be implicated in induced MB, where we report evidence for frontal deactivations during MB reports compared with other mental states. Contrast analysis between reports of MB and content-oriented mental states also revealed deactivations in the left angular gyrus. We propose that these effects characterize a neuronal profile of MB, where key thalamocortical nodes are unable to communicate and formulate reportable content. Collectively, we show that study instructions for MB lead to differential neural activation. These results provide mechanistic insights linked to the phenomenology of MB and point to the possibility of MB being expressed in different forms.SIGNIFICANCE STATEMENT This study explores how brain activity changes when individuals report unidentifiable thoughts, a phenomenon known as mind-blanking (MB). It aims to detect changes in brain activations and deactivations when MB is reported spontaneously, as opposed to the neural responses that have been previously reported when MB is induced. By means of brain imaging and experience-sampling, the study points to reduced brain activity in a wide number of regions, including those mesio-frontally which were previously detected as activated during induced MB. These results enhance our understanding of the complexity of spontaneous thinking and contribute to broader discussions on consciousness and reportable experience.
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  • 文章类型: Journal Article
    受损的反应抑制通常存在于患有注意力缺陷/多动障碍(ADHD)的个体及其未受影响的亲属中。提示反应抑制受损作为ADHD的候选内表型。因此,我们探讨了反应抑制的行为和神经相关性是否与ADHD的多基因风险评分(PRS-ADHD)相关.我们在NeuroIMAGE队列的停止信号任务中获得了神经活动和行为测量的功能磁共振成像,其中注意力不集中和多动冲动症状用Conners父母评定量表进行评估。我们的样本包括178例ADHD病例,103个未受影响的兄弟姐妹,和173名对照(总N=454;8-29年),可进行全基因组基因分型的人。使用PRSice-2软件构建PRS-ADHD。我们发现PRS-ADHD与ADHD症状严重程度有关,对围棋刺激的反应更慢、更多变,并在双侧前纹状体网络的几个区域的反应抑制期间改变了大脑激活。平均反应时间和个体内反应时间变异性介导了PRS-ADHD与ADHD症状的关联(总,注意力不集中,多动-冲动),抑制失败期间左颞极和海马前回的活动介导了PRS-ADHD与多动冲动的关系。我们的研究结果表明,PRS-ADHD与临床上的ADHD严重程度有关,次阈值,和正常水平;更重要的是,我们显示了ADHD的共同遗传病因与反应抑制的行为和神经相关。鉴于我们研究的样本量适中,未来有更高权力的研究有必要探索调解效果,提示ADHD的遗传倾向可能对行为水平的注意力调节产生不利影响,并指出从PRS-ADHD到多动-冲动的可能的应答抑制相关机制途径.
    Impaired response inhibition is commonly present in individuals with attention-deficit/hyperactivity disorder (ADHD) and their unaffected relatives, suggesting impaired response inhibition as a candidate endophenotype in ADHD. Therefore, we explored whether behavioral and neural correlates of response inhibition are related to polygenic risk scores for ADHD (PRS-ADHD). We obtained functional magnetic resonance imaging of neural activity and behavioral measures during a stop-signal task in the NeuroIMAGE cohort, where inattention and hyperactivity-impulsivity symptoms were assessed with the Conners Parent Rating Scales. Our sample consisted of 178 ADHD cases, 103 unaffected siblings, and 173 controls (total N = 454; 8-29 years), for whom genome-wide genotyping was available. PRS-ADHD was constructed using the PRSice-2 software. We found PRS-ADHD to be associated with ADHD symptom severity, a slower and more variable response to Go-stimuli, and altered brain activation during response inhibition in several regions of the bilateral fronto-striatal network. Mean reaction time and intra-individual reaction time variability mediated the association of PRS-ADHD with ADHD symptoms (total, inattention, hyperactivity-impulsivity), and activity in the left temporal pole and anterior parahippocampal gyrus during failed inhibition mediated the relationship of PRS-ADHD with hyperactivity-impulsivity. Our findings indicate that PRS-ADHD are related to ADHD severity on a spectrum of clinical, sub-threshold, and normal levels; more importantly, we show a shared genetic etiology of ADHD and behavioral and neural correlates of response inhibition. Given the modest sample size of our study, future studies with higher power are warranted to explore mediation effects, suggesting that genetic liability to ADHD may adversely affect attention regulation on the behavioral level and point to a possible response inhibition-related mechanistic pathway from PRS-ADHD to hyperactivity-impulsivity.
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