BACKGROUND & AIMS: :This article describes the effects of dexmedetomidine (DEX) - the active ingredient of medetomidine, which is the latest popular sedative for functional magnetic resonance imaging (fMRI) in rodents - on multiple unit activity, local field potential (LFP), cerebral blood flow (CBF), pial vessel diameter [indicative of cerebral blood volume (CBV)], and blood oxygenation level-dependent (BOLD) fMRI. These measurements were obtained from the rat somatosensory cortex during 10 s of forepaw stimulation. We found that the continuous intravascular systemic infusion of DEX (50 μg/kg/h, doses typically used in fMRI studies) caused epileptic activities, and that supplemental isoflurane (ISO) administration of ~0.3% helped to suppress the development of epileptic activities and maintained robust neuronal and hemodynamic responses for up to 3 h. Supplemental administration of N(2)O in addition to DEX nearly abolished hemodynamic responses even if neuronal activity remained. Under DEX + ISO anesthesia, spike firing rate and the delta power of LFP increased, whereas beta and gamma power decreased, as compared with ISO-only anesthesia. DEX administration caused pial arteries and veins to constrict nearly equally, resulting in decreases in baseline CBF and CBV. Evoked LFP and CBF responses to forepaw stimulation were largest at a frequency of 8-10 Hz, and a non-linear relationship was observed. Similarly, BOLD fMRI responses measured at 9.4 T were largest at a frequency of 10 Hz. Both pial arteries and veins dilated rapidly (artery, 32.2%; vein, 5.8%), and venous diameter returned to baseline slower than arterial diameter. These results will be useful for designing, conducting and interpreting fMRI experiments under DEX sedation.

背景与目标： ：本文介绍了右美托咪定（DEX）-美托咪定的活性成分，它是啮齿类动物功能磁共振成像（fMRI）的最新流行镇静剂-对多种单位活性，局部场电位（LFP），脑血流的影响（CBF），脉管直径[指示脑血容量（CBV）]和血液氧合水平依赖性（BOLD）fMRI。这些测量值是在前脚刺激10 s的过程中从大鼠的体感皮层获得的。我们发现，持续地进行全身性DEX血管内输注（50μg/ kg / h，fMRI研究中通常使用的剂量）引起癫痫活动，补充异氟烷（ISO）约0.3％的给药有助于抑制癫痫活动的发展，并且维持强劲的神经元和血液动力学反应长达3小时。即使保留神经元活性，除DEX外，N（2）O的补充给药几乎消除了血流动力学反应。与仅使用ISO的麻醉相比，在DEX ISO麻醉下，峰值放电频率和LFP的德尔塔功率增加，而β和γ功率下降。施用DEX可使颈动脉和静脉几乎均等地收缩，从而导致基线CBF和CBV降低。诱发的LFP和CBF对前爪刺激的响应最大，频率为8-10 Hz，并且观察到非线性关系。同样，在9.4 T下测得的BOLD fMRI反应最大，频率为10 Hz。颈动脉和静脉都迅速扩张（动脉，占32.2％；静脉，占5.8％），静脉直径恢复到基线的速度比动脉直径慢。这些结果对于在DEX镇静下设计，进行和解释fMRI实验将是有用的。

BACKGROUND & AIMS: :Transcranial brain mapping techniques, such as functional near-infrared spectroscopy (fNIRS) and transcranial magnetic stimulation (TMS), have been playing an increasingly important role in studies of human brain functions. Given a brain function of interest, fNIRS probes and TMS coils should be properly placed on the scalp to ensure that the function is effectively measured or modulated. However, since brain activity is inside the skull and invisible to the researcher during placement, this blind targeting may cause the device to partially or completely miss the functional target, resulting in inconsistent experimental results and divergent clinical outcomes, especially when participants' structural MRI data are not available. To address this issue, we propose here a framework for targeting a designated function directly from the scalp. First, a functional brain atlas for the targeted brain function is constructed via a meta-analysis of large-scale functional magnetic resonance imaging datasets. Second, the functional brain atlas is presented on the scalp surface by using a transcranial mapping previously established from an structural MRI dataset (n ​= ​114), resulting in a novel functional transcranial brain atlas (fTBA). Finally, a low-cost, portable scalp-navigation system is used to localize the transcranial device on the individual's scalp with the guidance of the fTBA. To demonstrate the feasibility of the targeting framework, both fNIRS and TMS mapping experiments were conducted. The results show that fTBA-guided fNIRS positioning can detect functional activity with high sensitivity and specificity for working memory and motor systems; Moreover, compared with traditional TMS targeting approaches (e.g. the International 10-20 System and the conventional 5-cm rule), the fTBA suggested motor stimulation site is closesr to both the motor hotspot and the center of gravity of motor evoked potentials (MEP-COG). In summary, the proposed method unblinds the transcranial function targeting process using prior information, providing an effective and straightforward approach to transcranial brain mapping studies, especially those without participants' structural MRI data.

背景与目标： ：经颅脑标测技术，例如功能性近红外光谱（fNIRS）和经颅磁刺激（TMS），在人类脑功能研究中发挥着越来越重要的作用。给定感兴趣的大脑功能，应将fNIRS探针和TMS线圈正确放置在头皮上，以确保有效地测量或调节该功能。但是，由于大脑活动处于颅骨内部，并且在放置过程中对研究人员不可见，因此这种盲目瞄准可能会导致设备部分或完全错过功能目标，从而导致不一致的实验结果和不同的临床结果，尤其是当参与者的结构MRI数据时不可用。为了解决这个问题，我们在这里提出了一个直接从头皮定位目标功能的框架。首先，通过大规模功能磁共振成像数据集的荟萃分析，构建了用于目标大脑功能的功能性大脑图集。其次，使用先前从结构MRI数据集建立的经颅映射（n = 114），将功能性脑图谱呈现在头皮表面上，从而产生一种新颖的经功能性颅脑图谱（fTBA）。最后，在fTBA的指导下，使用一种低成本的便携式头皮导航系统将经颅器械定位在个人头皮上。为了证明靶向框架的可行性，进行了fNIRS和TMS映射实验。结果表明，fTBA引导的fNIRS定位可以高灵敏度和高特异性地检测工作记忆和运动系统的功能活动。此外，与传统的TMS定位方法（例如，International 10-20 System和常规的5 cm规则）相比，fTBA建议的运动刺激部位靠近运动热点和运动诱发电位的重心（MEP- COG）。总而言之，所提出的方法利用先验信息对跨颅功能靶向过程进行了盲目处理，为跨颅脑绘图研究（尤其是没有参与者的MRI结构数据的研究）提供了一种有效而直接的方法。

BACKGROUND & AIMS: :Acquired disorders of gesture imitation are amenable to treatment, but with poor generalisation toward gestures not included in the training program. We investigated the neural basis of this item-specific recovery in a patient with a slowly progressive posterior cortical atrophy, by means of an fMRI study comparing imitation of rehabilitated and not-rehabilitated gestures. Results suggested that in our patient gesture imitation recruited the mirror system and additional areas relevant to gesture analysis and preparation. Imitation of rehabilitated gestures activated the mirror neuron system, and also left dorsolateral prefrontal cortex and putamen, and the right anterior temporal cortex. This suggests that item-specific recovery was based on interaction of circuitry of imitation with neural systems involved in emotional and motivational processing.

背景与目标： ：获得性手势模仿障碍可以接受治疗，但对培训计划中未包括的手势的概括性较差。我们通过功能磁共振成像研究比较了康复姿势和未康复姿势的模仿，研究了缓慢进展的后皮质萎缩患者这一特定恢复的神经基础。结果表明，在我们的患者手势模仿中，招募了镜子系统以及与手势分析和准备有关的其他区域。复原手势的模仿激活了镜像神经元系统，还激活了左外侧前额叶皮层和壳核，以及右侧前颞叶皮层。这表明特定项目的恢复是基于模仿电路与涉及情绪和动机处理的神经系统的相互作用。

BACKGROUND & AIMS: :The number of studies using functional magnetic resonance imaging (fMRI) has grown very rapidly since the first description of the technique in the early 1990s. Most published studies have utilized data analysis methods based on voxel-wise application of general linear models (GLM). On the other hand, temporal clustering analysis (TCA) focuses on the identification of relationships between cortical areas by measuring temporal common properties. In its most general form, TCA is sensitive to the low signal-to-noise ratio of BOLD and is dependent on subjective choices of filtering parameters. In this paper, we introduce a method for wavelet-based clustering of time-series data and show that it may be useful in data sets with low signal-to-noise ratios, allowing the automatic selection of the optimum number of clusters. We also provide examples of the technique applied to simulated and real fMRI datasets.

背景与目标： 自1990年代初对这项技术进行首次描述以来，使用功能磁共振成像（fMRI）的研究数量迅速增长。大多数已发表的研究都利用了基于一般线性模型（GLM）的体素化应用的数据分析方法。另一方面，时态聚类分析（TCA）侧重于通过测量时态共同属性来识别皮层区域之间的关系。在其最一般的形式中，TCA对BOLD的低信噪比敏感，并且取决于主观选择的滤波参数。在本文中，我们介绍了一种基于小波的时间序列数据聚类方法，并表明该方法在信噪比低的数据集中很有用，从而可以自动选择最佳聚类数。我们还提供了应用于模拟和真实fMRI数据集的技术示例。

BACKGROUND & AIMS: :Presurgical planning with fMRI benefits from increased reliability and the possibility to reduce measurement time introduced by using ultra-high field. Echo-planar imaging suffers, however, from geometric distortions which scale with field strength and potentially give rise to clinically significant displacement of functional activation. We evaluate the effectiveness of a dynamic distortion correction (DDC) method based on unmodified single-echo EPI in the context of simulated presurgical planning fMRI at 7T and compare it with static distortion correction (SDC). The extent of distortion in EPI and activation shifts are investigated in a group of eleven patients with a range of neuropathologies who performed a motor task. The consequences of neglecting to correct images for susceptibility-induced distortions are assessed in a clinical context. It was possible to generate time series of EPI-based field maps which were free of artifacts in the eloquent brain areas relevant to presurgical fMRI, despite the presence of signal dropouts caused by pathologies and post-operative sites. Distortions of up to 5.1mm were observed in the primary motor cortex in raw EPI. These were accurately corrected with DDC and slightly less accurately with SDC. The dynamic nature of distortions in UHF clinical fMRI was demonstrated via investigation of temporal variation in voxel shift maps, confirming the potential inadequacy of SDC based on a single reference field map, particularly in the vicinity of pathologies or in the presence of motion. In two patients, the distortion correction was potentially clinically significant in that it might have affected the localization or interpretation of activation and could thereby have influenced the treatment plan. Distortion correction is shown to be effective and clinically relevant in presurgical planning at 7T.

背景与目标： ：使用fMRI进行术前计划得益于更高的可靠性以及使用超高磁场引入的减少测量时间的可能性。然而，回波平面成像受几何失真的影响，几何失真随场强而缩放，并可能在临床上引起功能激活的明显位移。我们在7T模拟的术前计划fMRI的背景下，评估了基于未经修改的单回波EPI的动态失真校正（DDC）方法的有效性，并将其与静态失真校正（SDC）进行了比较。在一组执行运动任务的十一名神经病患者中，研究了EPI畸变和激活转移的程度。在临床环境中评估了忽略针对易感性失真的校正图像的后果。尽管存在由病理和术后部位引起的信号缺失，但有可能生成基于EPI的时间序列的时间序列，该序列在与术前功能磁共振成像相关的雄辩的大脑区域中没有伪影。在原始EPI中的初级运动皮层中观察到高达5.1mm的变形。这些已使用DDC进行了准确校正，而使用SDC进行了一些较不准确。通过研究体素位移图中的时间变化，证实了UHF临床功能磁共振成像中变形的动态性质，证实了基于单个参考场图的SDC的潜在不足，尤其是在病理学附近或存在运动的情况下。在两名患者中，畸变矫正可能在临床上具有重大意义，因为它可能影响了激活的定位或解释，从而影响了治疗计划。畸变矫正在7T的术前计划中被证明是有效的并且在临床上具有相关性。

BACKGROUND & AIMS: :Deception is a form of manipulation aimed at misleading another person by conveying false or truthful messages. Manipulative truthful statements could be considered as sophisticated deception and elicit an increased cognitive load. However, only one fMRI study reported its neural correlates. To provide independent evidence for sophisticated deception, we carried out an fMRI study replicating the experimental paradigm and Bayesian statistical approach utilized in that study. During the experiment, participants played a game against an opponent by sending deliberate deceptive or honest messages. Compared to truth-telling, deceptive intentions, regardless of how they were fulfilled, were associated with increased BOLD signals in the bilateral temporoparietal junction (TPJ), left precuneus, and right superior temporal sulcus (STS). The right TPJ participates in the attribution of mental states, acting in a social context, and moral behaviour. Moreover, the other revealed brain areas have been considered nodes in the theory of mind brain neural system. Therefore, the obtained results reflect an increased demand for socio‑cognitive processes associated with deceptive intentions. We replicated the original study showing the involvement of the right TPJ and expanded upon it by revealing the involvement of the left TPJ, left precuneus and right STS in actions with deceptive intentions.

背景与目标： ：欺骗是一种操纵手段，旨在通过传达虚假或真实的信息来误导他人。操纵真实的陈述可以被认为是复杂的欺骗，并会增加认知负担。但是，只有一项功能磁共振成像研究报告了其神经相关性。为了提供复杂欺骗的独立证据，我们进行了一项功能磁共振成像研究，该研究复制了该研究中使用的实验范式和贝叶斯统计方法。在实验过程中，参与者通过发送故意的欺骗性或诚实信息与对手进行比赛。与讲真话相比，无论其实现方式如何，欺骗性意图都与双侧颞顶交界处（TPJ），左前突和右颞颞沟（STS）中的BOLD信号增加有关。权利TPJ参与精神状态的归因，在社会环境中的行为和道德行为。此外，在大脑大脑神经系统理论中，其他被揭示的大脑区域也被认为是节点。因此，获得的结果反映出对与欺骗意图相关的社会认知过程的需求增加。我们复制了显示右TPJ参与的原始研究，并通过揭示左TPJ，左足前突和右STS在具有欺骗性意图的行为中的参与来扩大了研究范围。

BACKGROUND & AIMS: BACKGROUND AND STUDY AIMS: Cortical mapping (CM) with direct cortical stimulation (DCS) in awake craniotomy is used to preserve cognitive functions such as language. Nevertheless, patient collaboration during this procedure is influenced by previous neurological symptoms and growing discomfort with DCS duration. Our study aimed to evaluate the impact of navigated task-specific functional magnetic resonance imaging (nfMRI) on the practical aspects of DCS. MATERIAL AND METHODS: We recruited glioma patients scheduled for awake craniotomy for prior fMRI-based CM, acquired during motor and language tasks (i.e., verb generation, semantic and syntactic decision tasks). Language data was combined to generate a probabilistic map indicating brain regions activated with more than one paradigm. Presurgical neurophysiological language tests (i.e., verb generation, picture naming, and semantic tasks) were also performed. We considered for subsequent study only the patients with a minimum rate of correct responses of 50% in all tests. These patients were then randomized to perform intraoperative language CM either using the multimodal approach (mCM), using nfMRI and DCS combined, or electrical CM (eCM), with DCS alone. DCS was done while the patient performed picture naming and nonverbal semantic decision tasks. Methodological features such as DCS duration, number of stimuli, total delivered stimulus duration per task, and frequency of seizures were analyzed and compared between groups. The correspondence between positive responses obtained with DCS and nfMRI was also evaluated. RESULTS: Twenty-one surgeries were included, thirteen of which using mCM (i.e., test group). Patients with lower presurgical neuropsychological performance (correct response rate between 50 and 80% in language tests) showed a decreased DCS duration in comparison with the control group. None of the compared methodological features showed differences between groups. Correspondence between DCS and nfMRI was 100/84% in the identification of the precentral gyrus for motor function/opercular frontal inferior gyrus for language function, respectively. CONCLUSION: Navigated fMRI data did not influence DCS in practice. Presurgical language disturbances limited the applicability of DCS mapping in awake surgery.

背景与目标： 背景与研究目的：在清醒的开颅手术中使用带有直接皮质刺激（DCS）的皮质映射（CM）来保留诸如语言之类的认知功能。然而，在此过程中的患者协作会受到先前的神经症状和DCS持续时间的不适感的影响。我们的研究旨在评估导航任务特定功能磁共振成像（nfMRI）对DCS实用方面的影响。
材料和方法：我们招募了计划进行清醒开颅手术的脑胶质瘤患者，以进行基于功能磁共振成像的先前CM，并在运动和语言任务（即动词生成，语义和句法决策任务）中获得。语言数据被合并以生成一个概率图，该概率图指示了被多个范式激活的大脑区域。还进行了术前神经生理语言测试（即动词生成，图片命名和语义任务）。对于随后的研究，我们仅考虑所有测试中正确反应率最低为50％的患者。然后将这些患者随机分为两组，分别使用多模式方法（mCM），nfMRI和DCS组合或电CM（eCM）单独使用DCS进行术中语言CM。在患者执行图片命名和非言语语义决策任务的同时进行了DCS。分析方法特征，例如DCS持续时间，刺激次数，每项任务的总传递刺激持续时间以及癫痫发作频率，并在各组之间进行比较。还评估了DCS和nfMRI获得的阳性反应之间的对应关系。
结果：包括21例手术，其中13例使用mCM（即测试组）。与对照组相比，术前神经心理性能较低的患者（语言测试中正确的应答率在50％至80％之间）显示DCS持续时间缩短。比较的方法学特征均未显示组之间的差异。 DCS和nfMRI之间的对应关系在识别运动功能的中央前回/语言功能的额叶下回分别为100/84％。
结论：f功能性MRI数据在实践中不影响DCS。术前语言障碍限制了DCS绘图在清醒手术中的适用性。

BACKGROUND & AIMS: :Objective: Recent studies suggested that diabetic optic neuropathy(DON) independently increases the incidence of brain diseases like cerebral infarction and hemorrhage. In this study, voxel-level degree centrality (DC) was used to study potential changes in functional network brain activity in DON patients. Methods: The study included 14 DON patients and 14 healthy controls (HCs) matched by age, sex, and weight. All subjects underwent resting functional magnetic resonance imaging. Receiver operating characteristic curves and Pearson correlation analysis were performed. Results: The DC values of the left frontal mid orb (LFMO) and right middle frontal Gyrus (RMFG)/right frontal sup (RFS) were significantly lower in DON patients compared to HCs. The DC value of the left temporal lobe (LTL) was also significantly higher than in HCs. Conclusion: Three different brain regions show DC changes in DON patients, suggesting common optic neuropathy in the context of diabetes and providing new ideas for treating optic nerve disease in patients with long-term diabetes. Abbreviations: DC = degree centrality; DON = diabetic optic neuropathy; HC = healthy control; LFMO = left frontal mid orb; RMFS = right middle frontal gyrus; RFS = right frontal sup; LTL = left temporal lobe; FFA = fluorescein fundus angiography; fMRI = functional magnetic resonance imaging; VMHC = voxel-mirrored homotopic connectivity; ALFF = low-frequency fluctuation amplitude; AUC = area under the curve; BCVA = best corrected visual acuity.

背景与目标： ：目的：最近的研究表明，糖尿病性视神经病变（DON）独立增加了脑梗塞和出血等脑部疾病的发生率。在这项研究中，体素水平度中心（DC）用于研究DON患者的功能网络脑部活动的潜在变化。方法：该研究包括14例DON患者和14例按年龄，性别和体重配对的健康对照（HCs）。所有受试者均接受静息功能磁共振成像。进行接收机工作特性曲线和Pearson相关分析。结果：与HCs相比，DON患者的左额中球（LFMO）和右中额回（RMFG）/右额上视（RFS）的DC值显着降低。左颞叶（LTL）的DC值也显着高于HCs。结论：三个不同的大脑区域显示DON患者DC的变化，提示在糖尿病背景下常见的视神经病变，并为治疗长期糖尿病患者的视神经疾病提供了新的思路。缩写：DC =中心度； DON =糖尿病性视神经病变； HC =健康对照； LFMO =左额中球； RMFS =右中额回； RFS =右前额； LTL =左颞叶； FFA =荧光素眼底血管造影；功能磁共振成像=功能磁共振成像; VMHC =体素镜像同位连接； ALFF =低频波动幅度； AUC =曲线下面积； BCVA =最佳矫正视力。

BACKGROUND & AIMS: :Advances in breast cancer (BC) treatments have resulted in significantly improved survival rates. However, BC chemotherapy is often associated with several side effects including cognitive dysfunction. We applied multivariate pattern analysis (MVPA) to functional magnetic resonance imaging (fMRI) to find a brain connectivity pattern that accurately and automatically distinguishes chemotherapy-treated (C+) from non-chemotherapy treated (C-) BC females and healthy female controls (HC). Twenty-seven C+, 29 C-, and 30 HC underwent fMRI during an executive-prefrontal task (Go/Nogo). The pattern of functional connectivity associated with this task discriminated with significant accuracy between C+ and HC groups (72%, p = .006) and between C+ and C- groups (71%, p = .012). However, the accuracy of discrimination between C- and HC was not significant (51%, p = .46). Compared with HC, behavioral performance of the C+ and C- groups during the task was intact. However, the C+ group demonstrated altered functional connectivity in the right frontoparietal and left supplementary motor area networks compared to HC, and in the right middle frontal and left superior frontal gyri networks, compared to C-. Our results provide further evidence that executive function performance may be preserved in some chemotherapy-treated BC survivors through recruitment of additional neural connections.

背景与目标： ：乳腺癌（BC）治疗方面的进展已显着提高了存活率。但是，BC化疗通常与多种副作用相关，包括认知功能障碍。我们将多元模式分析（MVPA）应用到功能磁共振成像（fMRI）中，以找到一种大脑连接模式，该模式可以准确，自动地将化学疗法治疗的（C）与非化学疗法治疗的（C-）BC女性和健康女性对照（HC）区分开来）。在执行前额任务（Go / Nogo）时，对27 C，29 C和30 HC进行了功能磁共振成像。 C和HC组之间（72％，p = .006）以及C和C-组之间（71％，p = .012）的准确度高，可以区分与此任务相关的功能连接模式。但是，C-和HC区分的准确性不高（51％，p = 0.46）。与HC相比，C和C-组在任务期间的行为表现是完整的。但是，与C-组相比，C组在右额顶和左侧辅助运动区域网络中以及右中额叶和左上额回回网络中的功能连接性均发生了改变。我们的结果提供了进一步的证据，即通过募集额外的神经连接，在某些经化学疗法治疗的BC幸存者中可以保留执行功能。

BACKGROUND & AIMS: :Similar "what/where" functional segregations have been proposed for both visual and auditory cortical processing. In this fMRI study, we investigated if the same segregation exists in the crossmodal domain, when visual and auditory stimuli have to be matched in order to perform either a recognition or a localization task. Recent neuroimaging research highlighted the contribution of different heteromodal cortical regions during various forms of crossmodal binding. Interestingly, crossmodal effects during audiovisual speech and object recognition have been found in the superior temporal sulcus, while crossmodal effects during the execution of spatial tasks have been found over the intraparietal sulcus, suggesting an underlying "what/where" segregation. In order to directly compare the specific involvement of these two heteromodal regions, we scanned ten male right-handed subjects during the execution of two crossmodal matching tasks. Participants were simultaneously presented with a picture and an environmental sound, coming from either the same or the opposite hemifield and representing either the same or a different object. The two tasks required a manual YES/NO response respectively about location or semantic matching of the presented stimuli. Both group and individual subject analysis were performed. Task-related differences in BOLD response were observed in the right intraparietal sulcus and in the left superior temporal sulcus, providing a direct confirmation of the "what-where" functional segregation in the crossmodal audiovisual domain.

背景与目标： 对于视觉和听觉皮层处理，已经提出了类似的“什么/在哪里”功能隔离。在这项功能磁共振成像研究中，我们调查了在视觉和听觉刺激必须匹配以执行识别或定位任务时，交叉模态域中是否存在相同的隔离。最近的神经影像学研究强调了在各种形式的交叉峰结合中不同异峰皮质区域的贡献。有趣的是，在上颞沟中发现了视听语音和物体识别过程中的交叉峰效应，而在顶壁沟中发现了执行空间任务期间的交叉峰效应，表明了潜在的“什么/在哪里”隔离。为了直接比较这两个异峰区域的具体参与情况，我们在执行两个交叉峰匹配任务期间扫描了十个男性惯用右手的受试者。与会者同时获得来自同一或相反半场的图像和环境声音，并代表相同或不同的物体。这两个任务需要分别对所显示刺激的位置或语义匹配进行手动“是/否”响应。进行小组和个体受试者分析。在右侧顶壁沟和左侧颞上沟中观察到与任务相关的BOLD反应差异，这直接证实了跨模态视听域中“何处”功能分离。

BACKGROUND & AIMS: :Delineation of large-scale functional networks (FNs) from resting state functional MRI data has become a standard tool to explore the functional brain organization in neuroscience. However, existing methods sacrifice subject specific variation in order to maintain the across-subject correspondence necessary for group-level analyses. In order to obtain subject specific FNs that are comparable across subjects, existing brain decomposition techniques typically adopt heuristic strategies or assume a specific statistical distribution for the FNs across subjects, and therefore might yield biased results. Here we present a novel data-driven method for detecting subject specific FNs while establishing group level correspondence. Our method simultaneously computes subject specific FNs for a group of subjects regularized by group sparsity, to generate subject specific FNs that are spatially sparse and share common spatial patterns across subjects. Our method is built upon non-negative matrix decomposition techniques, enhanced by a data locality regularization term that makes the decomposition robust to imaging noise and improves spatial smoothness and functional coherences of the subject specific FNs. Our method also adopts automatic relevance determination techniques to eliminate redundant FNs in order to generate a compact set of informative sparse FNs. We have validated our method based on simulated, task fMRI, and resting state fMRI datasets. The experimental results have demonstrated our method could obtain subject specific, sparse, non-negative FNs with improved functional coherence, providing enhanced ability for characterizing the functional brain of individual subjects.

背景与目标： ：从静止状态的功能性MRI数据中划定大型功能网络（FNs）已成为探索神经科学中功能性大脑组织的标准工具。然而，现有方法牺牲了受试者特定的变异性，以维持组水平分析所必需的跨学科对应。为了获得在各个受试者之间可比较的特定于受试者的FN，现有的大脑分解技术通常采用启发式策略或对各个受试者的FN采取特定的统计分布，因此可能会产生偏差的结果。在这里，我们提出了一种新的数据驱动方法，用于在建立组级别对应关系时检测主题特定的FN。我们的方法同时为一组由组稀疏性正规化的主题计算特定主题FN，以生成空间稀疏且在各个主题之间共享公共空间模式的特定主题FN。我们的方法建立在非负矩阵分解技术的基础上，并通过数据局部性正则化术语进行了增强，该术语使分解对图像噪声具有鲁棒性，并提高了主题特定FN的空间平滑度和功能相干性。我们的方法还采用自动相关性确定技术来消除冗余FN，以便生成一组紧凑的信息稀疏FN。我们已经基于模拟，任务功能磁共振成像和静止状态功能磁共振成像数据集验证了我们的方法。实验结果表明，我们的方法可以获得具有改进的功能一致性的受试者特异性，稀疏，非阴性FN，从而增强了表征单个受试者的功能性大脑的能力。

BACKGROUND & AIMS: :Gender specific effects on human eating have been previously reported. Here we investigated sex-based differences in neural activation via whole-brain blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in response to high energy-dense (high-ED) vs. low-ED visual and auditory food cues in obese men vs. women in both fed and fasted states. The results show that in response to high vs. low ED foods in the fed state, obese men (vs. women) had greater activation in brain areas associated with motor control regions (e.g. supplementary motor areas) whereas women showed greater activation in cognitive-related regions. In the fasted state, obese men had greater activation in a visual-attention region whereas obese women showed greater activation in affective and reward related processing regions (e.g. caudate). Overall the results support our a priori hypothesis that obese women (vs. men) have greater neural activation in regions associated with cognition and emotion-related brain regions. These findings may improve our understanding of sex specific differences among obese individuals in eating behavior.

背景与目标： ：先前已经报道了性别对人类饮食的影响。在这里，我们通过对高能量密度（high-ED）与低ED视觉和听觉食物的反应，通过全脑血氧水平依赖性（BOLD）功能磁共振成像（fMRI）研究了神经激活中基于性别的差异在进食和禁食状态下，肥胖男性与女性的暗示。结果表明，在进食状态下，高ED和低ED食物相对应，肥胖男性（相对于女性）在与运动控制区域（例如，补充运动区域）相关的大脑区域具有更大的激活，而女性在认知-运动方面表现出更大的激活。相关区域。在禁食状态下，肥胖男性在视觉注意区域的激活程度更高，而肥胖女性在与情感和奖励相关的加工区域（例如尾状）的激活程度更高。总体而言，这些结果支持了我们的先验假设，即肥胖女性（相对于男性）在与认知和情绪相关的大脑区域相关的区域具有更大的神经激活作用。这些发现可能会增进我们对肥胖个体饮食行为之间性别差异的理解。

BACKGROUND & AIMS: BACKGROUND:In this case series, functional magnetic resonance imaging was used to examine brain networks that mediate different aspects of language function in 4 young adults (17-22 years) with a history of left middle cerebral artery (MCA) stroke in childhood (40 years of age). Although it is widely believed that altered lateralization patterns are more likely to occur following early brain injuries compared with later brain injuries, the presumed plasticity of the young brain has been challenged in recent years, particularly in the domain of language. METHODS:We explored this issue by contrasting the brain activation patterns of individuals with childhood left MCA stroke and adult left MCA stroke while performing two language tasks: verb generation and picture-word matching. Importantly, both groups showed significant recovery of language function, based on standard clinical indicators. RESULTS:Controls showed left lateralized activation for both tasks, although much more pronounced for verb generation. Adult stroke patients also showed left lateralization for both tasks, though somewhat weaker than controls. Childhood stroke patients exhibited significantly weaker lateralization than the adult group for verb generation, but there was no significant group difference for picture-word matching. CONCLUSIONS:These preliminary findings suggest that successful reorganization of language function is more likely to involve bilateral recruitment following left MCA stroke in childhood than in adulthood. Of importance, although childhood stroke patients had primarily subcortical lesions, there were substantial alterations in cortical activation patterns.

背景与目标： 背景：在本案例系列中，功能磁共振成像被用来检查介导4名年轻人（17岁至22岁）有儿童左中脑动脉中风病史的语言网络，这些语言介导语言功能的不同方面（40岁）岁）。尽管人们普遍认为，与早期脑部受伤相比，早期脑部受伤后更容易发生偏侧化模式，但近年来，尤其是在语言领域，年轻的大脑的可塑性受到了挑战。
方法：我们通过对比儿童左MCA卒中和成人MCA卒中个体的大脑激活模式，同时执行两种语言任务：动词生成和图片词匹配，探讨了这个问题。重要的是，根据标准的临床指标，两组都显示出语言功能的显着恢复。
结果：控件显示这两个任务的左侧横向激活，尽管在动词生成方面更为明显。成年卒中患者在这两项任务中也表现出左侧偏侧性，尽管比对照组弱一些。童年期中风患者在动词生成方面比成人组表现出明显弱化的偏侧性，但是在图片-单词匹配方面没有显着的组别差异。
结论：这些初步研究结果表明，语言功能的成功重组与儿童成年后MCA卒中后的双边招募有关。重要的是，尽管儿童中风患者主要患有皮层下病变，但皮层激活模式有实质性改变。

BACKGROUND & AIMS: :This paper addresses the issue of the central correlates of the "Kohnstamm phenomenon", i.e. the long-lasting involuntary muscle contraction which develops after a prolonged isometric voluntary contraction. Although this phenomenon was described as early as 1915, the mechanisms underlying these post-effects are not yet understood. It was therefore proposed to investigate whether specific brain areas may be involved in the motor post-effects induced by either wrist muscle contraction or vibration using the fMRI method. For this purpose, experiments were carried out on the right wrist of 11 healthy subjects. Muscle activity (EMG) and regional cerebral blood flow were recorded during isometric voluntary muscle contraction and muscle vibration, as well as during the subsequent involuntary contractions (the post-effects) which occurred under both conditions. Brain activations were found to occur during the post-contraction and post-vibration periods, which were very similar under both conditions. Brain activation involved motor-related areas usually responsible for voluntary motor command (primary sensory and motor cortices, premotor cortex, anterior and posterior cingulate gyrus) and sensorimotor integration structures such as the posterior parietal cortex. Comparisons between the patterns of brain activation associated with the involuntary post-effects and those accompanying voluntary contraction showed that cerebellar vermis was activated during the post-effect periods whereas the supplementary motor area was activated only during the induction periods. Although post-effects originate from asymmetric proprioceptive inputs, they might also involve a central network where the motor and somatosensory areas and the cerebellum play a key role. In functional terms, they might result from the adaptive recalibration of the postural reference frame altered by the sustained proprioceptive inputs elicited by muscle contraction and vibration.

背景与目标： ：本文解决了“ Kohnstamm现象”的核心相关性问题，即长期等距自愿收缩后出现的持续性非自愿性肌肉收缩。尽管早在1915年就已经描述了这种现象，但尚未理解这些后效应的潜在机制。因此，建议使用fMRI方法研究特定的大脑区域是否可能与腕部肌肉收缩或振动引起的运动后效应有关。为此，在11名健康受试者的右手腕上进行了实验。在等距自愿性肌肉收缩和肌肉振动期间，以及随后在这两种情况下发生的非自愿收缩（后效应）过程中，均记录了肌肉活动（EMG）和局部脑血流量。发现大脑的激活发生在收缩后和振动后的时期，在两种情况下都非常相似。脑部激活涉及通常与自主运动命令有关的运动相关区域（主要的感觉和运动皮层，运动前皮层，前扣带回和后扣带回）和感觉运动整合结构，例如后顶叶皮层。比较与非自愿性后效应相关的脑部激活模式和伴随自愿性收缩的脑部激活模式，结果表明小脑mis部在后效应期被激活，而辅助运动区仅在诱导期被激活。尽管后效应源于不对称的本体感受输入，但它们也可能涉及一个中央网络，其中运动和体感区以及小脑起着关键作用。从功能上讲，它们可能是由于姿势的参考系的自适应重新校准而产生的，而姿势的参考系是由肌肉收缩和振动引起的持续本体感觉输入改变的。

BACKGROUND & AIMS: :Stimulus-reward coupling without attention can induce highly specific perceptual learning effects, suggesting that reward triggers selective plasticity within visual cortex. Additionally, dopamine-releasing events-temporally surrounding stimulus-reward associations-selectively enhance memory. These forms of plasticity may be evoked by selective modulation of stimulus representations during dopamine-inducing events. However, it remains to be shown whether dopaminergic signals can selectively modulate visual cortical activity. We measured fMRI activity in monkey visual cortex during reward-only trials apart from intermixed cue-reward trials. Reward without visual stimulation selectively decreased fMRI activity within the cue representations that had been paired with reward during other trials. Behavioral tests indicated that these same uncued reward trials strengthened cue-reward associations. Furthermore, such spatially-specific activity modulations depended on prediction error, as shown by manipulations of reward magnitude, cue-reward probability, cue-reward familiarity, and dopamine signaling. This cue-selective negative reward signal offers a mechanism for selectively gating sensory cortical plasticity.

背景与目标： ：注意力不集中的刺激-奖励耦合可以诱导高度特定的知觉学习效果，这表明奖励触发了视觉皮层内的选择性可塑性。另外，多巴胺释放事件-暂时围绕刺激-奖励关联-有选择地增强了记忆。这些形式的可塑性可以通过在多巴胺诱导事件期间选择性地刺激刺激来引起。但是，多巴胺能信号是否可以选择性调节视觉皮层活动仍有待观察。除了混合提示奖赏试验外，我们在仅奖励试验期间测量了猴子视皮层的fMRI活性。没有视觉刺激的奖励选择性地降低了在其他试验中已与奖励配对的提示表征内的功能磁共振成像活动。行为测试表明，这些相同的无提示的奖励试验加强了线索与奖励的联系。此外，这种空间特定的活动调制取决于预测误差，如奖励幅度，提示奖励概率，提示奖励熟悉度和多巴胺信号传导的操纵所示。这种提示选择性的负奖励信号提供了一种选择性地控制感觉皮层可塑性的机制。