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At present, our knowledge about seasonal affective disorder (SAD) is based mainly up on clinical symptoms, epidemiology, behavioral characteristics and light therapy. Recently developed measures of resting‐state functional brain activity might provide neurobiological markers of brain disorders. Studying functional brain activity in SAD could enhance our understanding of its nature and possible treatment strategies. Functional network connectivity (measured using ICA‐dual regression), and amplitude of low‐frequency fluctuations (ALFF) were measured in 45 antidepressant‐free patients (39.78 ± 10.64, 30 ♀, 15 ♂) diagnosed with SAD and compared with age‐, gender‐ and ethnicity‐matched healthy controls (HCs) using resting‐state functional magnetic resonance imaging. After correcting for Type 1 error at high model orders (inter‐RSN correction), SAD patients showed significantly increased functional connectivity in 11 of the 47 identified RSNs. Increased functional connectivity involved RSNs such as visual, sensorimotor, and attentional networks. Moreover, our results revealed that SAD patients compared with HCs showed significant higher ALFF in the visual and right sensorimotor cortex. Abnormally altered functional activity detected in SAD supports previously reported attentional and psychomotor symptoms in patients suffering from SAD. Further studies, particularly under task conditions, are needed in order to specifically investigate cognitive deficits in SAD. Hum Brain Mapp 35:161–172, 2014. © 2012 Wiley Periodicals, Inc.  相似文献   

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Moral injury is closely associated with posttraumatic stress disorder (PTSD) and characterized by disturbances in social and moral cognition. Little is known about the neural underpinnings of moral injury, and whether the neural correlates are different between moral injury and PTSD. A sample of 26 U.S. military veterans (two females: 28–55 years old) were investigated to determine how subjective appraisals of morally injurious events measured by Moral Injury Event Scale (MIES) and PTSD symptoms are differentially related to spontaneous fluctuations indexed by amplitude of low frequency fluctuation (ALFF) as well as functional connectivity during resting‐state functional magnetic resonance imaging scanning. ALFF in the left inferior parietal lobule (L‐IPL) was positively associated with MIES subscores of transgressions, negatively associated with subscores of betrayals, and not related with PTSD symptoms. Moreover, functional connectivity between the L‐IPL and bilateral precuneus was positively related with PTSD symptoms and negatively related with MIES total scores. Our results provide the first evidence that morally injurious events and PTSD symptoms have dissociable neural underpinnings, and behaviorally distinct subcomponents of morally injurious events are different in neural responses. The findings increase our knowledge of the neural distinctions between moral injury and PTSD and may contribute to developing nosology and interventions for military veterans afflicted by moral injury.  相似文献   

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A growing literature has focused on the brain's ability to augment processing in local regions by recruiting distant communities of neurons in response to neural decline or insult. In particular, both younger and older adult populations recruit bilateral prefrontal cortex (PFC) as a means of compensating for increasing neural effort to maintain successful cognitive function. However, it remains unclear how local changes in neural activity affect the recruitment of this adaptive mechanism. To address this problem, we combined graph theoretical measures from functional MRI with diffusion weighted imaging and repetitive transcranial magnetic stimulation (rTMS) to resolve a central hypothesis: how do aged brains flexibly adapt to local changes in cortical activity? Specifically, we applied neuromodulation to increase or decrease local activity in a cortical region supporting successful memory encoding (left dorsolateral PFC or DLPFC) using 5 or 1 Hz rTMS, respectively. We then assessed a region's local within‐module degree, or the distributed between‐module degree (BMD) between distant cortical communities. We predicted that (1) local stimulation‐related deficits may be counteracted by boosting BMD between bilateral PFC, and that this effect should be (2) positively correlated with structural connectivity. Both predictions were confirmed; 5 Hz rTMS increased local success‐related activity and local increases in PFC connectivity, while 1 Hz rTMS decreases local activity and triggered a more distributed pattern of bilateral PFC connectivity to compensate for this local inhibitory effect. These results provide an integrated, causal explanation for the network interactions associated with successful memory encoding in older adults. Hum Brain Mapp 38:5987–6004, 2017 . © 2017 Wiley Periodicals, Inc.  相似文献   

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In the normal aging process, the functional connectome restructures and shows a shift from more segregated to more integrated brain networks, which manifests itself in highly different cognitive performances in older adults. Underpinnings of this reorganization are not fully understood, but may be related to age‐related differences in structural connectivity, the underlying scaffold for information exchange between regions. The structure–function relationship might be a promising factor to understand the neurobiological sources of interindividual cognitive variability, but remain unclear in older adults. Here, we used diffusion weighted and resting‐state functional magnetic resonance imaging as well as cognitive performance data of 573 older subjects from the 1000BRAINS cohort (55–85 years, 287 males) and performed a partial least square regression on 400 regional functional and structural connectivity (FC and SC, respectively) estimates comprising seven resting‐state networks. Our aim was to identify FC and SC patterns that are, together with cognitive performance, characteristic of the older adults aging process. Results revealed three different aging profiles prevalent in older adults. FC was found to behave differently depending on the severity of age‐related SC deteriorations. A functionally highly interconnected system is associated with a structural connectome that shows only minor age‐related decreases. Because this connectivity profile was associated with the most severe age‐related cognitive decline, a more interconnected FC system in older adults points to a process of dedifferentiation. Thus, functional network integration appears to increase primarily when SC begins to decline, but this does not appear to mitigate the decline in cognitive performance.  相似文献   

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Machine learning methods have increasingly been used to map out brain‐behavior associations (BBA), and to predict out‐of‐scanner behavior of unseen subjects. Given the brain changes that occur in the context of aging, the accuracy of these predictions is likely to depend on how similar the training and testing data sets are in terms of age. To this end, we examined how well BBAs derived from an age‐group generalize to other age‐groups. We partitioned the CAM‐CAN data set (N = 550) into the young, middle, and old age‐groups, then used the young and old age‐groups to construct prediction models for 11 behavioral outcomes using multimodal neuroimaging features (i.e., structural and resting‐state functional connectivity, and gray matter volume/cortical thickness). These models were then applied to all three age‐groups to predict their behavioral scores. When the young‐derived models were used, a graded pattern of age‐generalization was generally observed across most behavioral outcomes—predictions are the most accurate in the young subjects in the testing data set, followed by the middle and then old‐aged subjects. Conversely, when the old‐derived models were used, the disparity in the predictive accuracy across age‐groups was mostly negligible. These findings hold across different imaging modalities. These results suggest the asymmetric age‐generalization of BBAs—old‐derived BBAs generalized well to all age‐groups, however young‐derived BBAs generalized poorly beyond their own age‐group.  相似文献   

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Hippocampal circuit alterations that differentially affect hippocampal subfields are associated with age‐related memory decline. Additionally, functional organization along the longitudinal axis of the hippocampus has revealed distinctions between anterior and posterior (A‐P) connectivity. Here, we examined the functional connectivity (FC) differences between young and older adults at high‐resolution within the medial temporal lobe network (entorhinal, perirhinal, and parahippocampal cortices), allowing us to explore how hippocampal subfield connectivity across the longitudinal axis of the hippocampus changes with age. Overall, we found reliably greater connectivity for younger adults than older adults between the hippocampus and parahippocampal cortex (PHC) and perirhinal cortex (PRC). This drop in functional connectivity was more pronounced in the anterior regions of the hippocampus than the posterior ones, consistent for each of the hippocampal subfields. Further, intra‐hippocampal connectivity also reflected an age‐related decrease in functional connectivity within the anterior hippocampus in older adults that was offset by an increase in posterior hippocampal functional connectivity. Interestingly, the anterior–posterior dysfunction in older adults between hippocampus and PHC was predictive of lure discrimination performance on the Mnemonic similarity task (MST), suggesting a role in memory performance. While age‐related dysfunction within the hippocampal subfields has been well‐documented, these results suggest that the age‐related dysfunction in hippocampal connectivity across the longitudinal axis may also contribute significantly to memory decline in older adults.  相似文献   

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Recent studies have suggested that emotional reactivity changes with age, but the neural basis is still unclear. The insula may be critical for the emotional reactivity. The current study examined how ageing affects emotional reactivity using the emotional reactivity task data from a human sample (Cambridge Center for Age and Neuroscience, N = 243, age 18–88 years). The resting-state magnetic resonance measurements from the same sample were used to investigate the potential mechanisms of the insula. In the initial analysis, we conducted partial correlation assessments to examine the associations between emotional reactivity and age, as well as between the gray matter volume (GMV) of the insula and age. Our results revealed that emotional reactivity, especially positive emotional reactivity, decreased with age and that the GMV of the insula was negatively correlated with age. Subsequently, the bilateral insula was divided into six subregions to calculate the whole brain resting-state functional connectivity (rsFC). The mediating effect of the rsFC on age and emotional reactivity was then calculated. The results showed that the rsFC of the left anterior insula (AI) with the right hippocampus, and the rsFCs of the right AI with the striatum and the thalamus were mediated the relationship between positive emotional reactivity and age. Our findings suggest that attenuating emotional reactivity with age may be a strategic adaptation fostering emotional stability and diminishing emotional vulnerability. Meanwhile, the findings implicate a key role for the AI in the changes in positive emotional reactivity with age.  相似文献   

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目的 利用静息态fMRI探讨长期海洛因成瘾者前额叶功能连接的变化情况.方法 13例长期海洛因成瘾者和14例正常者接受静息态fMRI检查,对数据进行相关的预处理后,以前额叶为种子点与全脑每个体素进行相关分析,比较海洛因成瘾组与正常对照组前额叶功能连接的变化情况.结果 以左侧前额叶为种子点进行功能连接分析,海洛因成瘾组左侧前额叶与左侧海马、右侧前扣带回、左侧额中回、右侧额中回、右侧楔前叶功能连接明显低于正常对照组:以右侧前额叶为种子点进行功能连接分析,海洛因成瘾组右侧前额叶与左侧眶额叶、左侧额中回功能连接明显低于正常对照组.结论 长期海洛因成瘾者前额叶与相关脑区的功能连接减弱,前额叶可能参与了海洛因成瘾的维持与戒断后复吸.
Abstract：
Objective To explore the changes of functional connectivity of the prefrontal cortex in chronic heroin addicts under resting-state functional MRI (fMRI). Methods Resting fMRI examination was performed on 13 chronic heroin addicts and 14 healthy volunteers. After pre-processing the resting-state fMRI data, the prefrontal cortex was selected as the seed region, with which a whole-brain voxel temporal correlation in Iow frequency fMRI fluctuations was analyzed and the changes of functional connectivity of the prefrontal lobe in both chronic heroin addicts and healthy volunteers were calculated with SPM5 software. Results Compared with that in the control group, the functional connectivity between the left prefrontal cortex and the left hippocampus, right anterior cingulate, left middle frontal gyrus, right middle frontal gyrus, right precuneus in the heroin addiction group was significantly decreased. The functional connectivity between the right prefrontal cortex and the left orbital frontal cortex, left middle frontal gyrus in thc heroin addiction group was also significantly decreased as compared with that in the control group. Conclusion Functional connectivity of prefrontal cortex in chronic heroin addicts decreases, indicating that the prefrontal cortex may be involved in the maintenance of heroin addiction and relapse after withdrawal.  相似文献   

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Alcohol use disorder (AUD) is associated with changes in frontostriatal connectivity, but functional magnetic resonance imaging (fMRI) functional connectivity (FC) approaches are usually not adapted to these circuits. We developed a circuit‐specific fMRI analysis approach to detect dynamic changes in frontostriatal FC inspired by medial‐ventral‐rostral to lateral‐dorsal‐caudal frontostriatal gradients originally identified in nonhuman primate tract‐tracing data. In our PeaCoG (“ pea k co nnectivity on a g radient”) approach we use information about the location of strongest FC on empirical frontostriatal connectivity gradients. We have recently described a basic PeaCoG version with conventional FC, and now developed a dynamic PeaCoG approach with sliding‐window FC. In resting state data of n = 66 AUD participants and n = 40 healthy controls we continue here the analyses that we began with the basic version. Our former result of an AUD‐associated ventral shift in right orbitofrontal cortex PeaCoG is consistently detected in the dynamic approach. Temporospatial variability of dynamic PeaCoG in the left dorsolateral prefrontal cortex is reduced in AUD and associated with self‐efficacy to abstain and days of abstinence. Our method has the potential to provide insight into the dynamics of frontostriatal circuits, which has so far been relatively unexplored, and into their role in mental disorders and normal cognition.  相似文献   

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The importance of studying connectivity in the aging brain is increasingly recognized. Recent studies have shown that connectivity within the default mode network is reduced with age and have demonstrated a clear relation of these changes with cognitive functioning. However, research on age‐related changes in other functional networks is sparse and mainly focused on prespecified functional networks. Using functional magnetic resonance imaging, we investigated age‐related changes in functional connectivity during a visual oddball task in a range of functional networks. It was found that compared with young participants, elderly showed a decrease in connectivity between areas belonging to the same functional network. This was found in the default mode network and the somatomotor network. Moreover, in all identified networks, elderly showed increased connectivity between areas within these networks and areas belonging to different functional networks. Decreased connectivity within functional networks was related to poorer cognitive functioning in elderly. The results were interpreted as a decrease in the specificity of functional networks in older participants. Hum Brain Mapp 35:319–330, 2014. © 2012 Wiley Periodicals, Inc.  相似文献   

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目的 利用静息态功能磁共振(fMRI)分析网络游戏成瘾者与伏核存在功能连接的脑区,了解伏核功能异常在网络游戏成瘾发病机制中的作用.方法 网络游戏成瘾者和健康对照组各17例,扫描前上网玩耍自己喜欢的网络游戏,60 min后突然中止网络使用,对被试的网络游戏渴求程度进行心理学测评;休息30 min后进行静息态fMRI扫描,分别选取左、右侧伏核为感兴趣区进行脑功能连接分析,确定与双侧伏核有功能连接的脑区,并将激活程度与网络游戏渴求程度进行相关分析.结果 网络游戏成瘾青少年对网络游戏内容的渴望程度、喜欢程度、再次上网的渴望程度明显高于健康对照组(P＜0.05);网络游戏成瘾组的伏核与前扣带回、中脑、海马功能连接明显高于健康对照组,而与前额叶、颞叶及枕叶功能连接明显低于健康对照组(P＜0.05);网络游戏成瘾者伏核与前额叶、前扣带回、中脑及海马的功能连接程度和网络游戏渴求程度存在相关性(r=0.70、0.76、0.65、0.79,P＜0.05).结论 网络游戏成瘾者伏核功能异常,提示伏核是网络游戏成瘾“奖赏系统”的重要组成部分,伏核功能异常可能参与了网络游戏成瘾的产生与维持.  相似文献   

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Previous research in young adults has demonstrated that both motor learning and transcranial direct current stimulation (tDCS) trigger decreases in the levels of gamma‐aminobutyric acid (GABA) in the sensorimotor cortex, and these decreases are linked to greater learning. Less is known about the role of GABA in motor learning in healthy older adults, a knowledge gap that is surprising given the established aging‐related reductions in sensorimotor GABA. Here, we examined the effects of motor learning and subsequent tDCS on sensorimotor GABA levels and resting‐state functional connectivity in the brains of healthy older participants. Thirty‐six older men and women completed a motor sequence learning task before receiving anodal or sham tDCS to the sensorimotor cortex. GABA‐edited magnetic resonance spectroscopy of the sensorimotor cortex and resting‐state (RS) functional magnetic resonance imaging data were acquired before and after learning/stimulation. At the group level, neither learning nor anodal tDCS significantly modulated GABA levels or RS connectivity among task‐relevant regions. However, changes in GABA levels from the baseline to post‐learning session were significantly related to motor learning magnitude, age, and baseline GABA. Moreover, the change in functional connectivity between task‐relevant regions, including bilateral motor cortices, was correlated with baseline GABA levels. These data collectively indicate that motor learning‐related decreases in sensorimotor GABA levels and increases in functional connectivity are limited to those older adults with higher baseline GABA levels and who learn the most. Post‐learning tDCS exerted no influence on GABA levels, functional connectivity or the relationships among these variables in older adults.  相似文献   

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Previous studies have demonstrated that four latent variables, or reference abilities (RAs), can account for the majority of age‐related changes in cognition: these being episodic memory, fluid reasoning, speed of processing, and vocabulary. In the current study, we focused on RA‐selective functional connectivity patterns that vary with both age and behavior. We analyzed fMRI data from 287 community‐dwelling adults (20–80 years) on a battery of tests relating to the four RAs (three tests per RA = 12 tests). Functional connectivity values were calculated between a pre‐defined set of 264 ROIs (nodes). Across all participants, we (a) identified connections (edges) that correlated with an RA‐specific indicator variable and, indexing only these edges; (b) performed linear regression analysis per edge, regressing indicator correlations (Model 1) and connectivity values (Model 2) on Age, Behavioral Performance, and the Interaction term; and (c) took the conjunction of significant edges between models. Results revealed a different subset of edges for each RA whose connectivity strength and domain‐selectivity varied with age and behavior. Strikingly, the fluid reasoning RA was particularly vulnerable to the effects of age and displayed the most extensive connectivity and selectivity “footprint” for behavior. These findings indicate that different functional networks are recruited across RA, with fluid reasoning displaying a special status among them.  相似文献   

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Age‐related behavioral declines may be the result of deterioration of white matter tracts, affecting brain structural (SC) and functional connectivity (FC) during resting state. To date, it is not clear if the combination of SC and FC data could better predict cognitive/motor performance than each measure separately. We probed these relationships in the cingulum bundle, a major white matter pathway of the default mode network. We aimed to attain deeper knowledge about: (a) the relationship between age and the cingulum's SC and FC strength, (b) the association between SC and FC, and particularly (c) how the cingulum's SC and FC are related to cognitive/motor performance separately and combined. We examined these associations in a healthy and well‐educated sample of 165 older participants (aged 64‐85). SC and FC were acquired using probabilistic tractography to derive measures to capture white matter integrity within the cingulum bundle (fractional anisotropy, mean, axial and radial diffusivity) and a seed‐based resting‐state functional MRI correlation approach, respectively. Participants performed cognitive tests measuring processing speed, memory and executive functions, and motor tests measuring motor speed and grip force. Our data revealed that only SC but not resting state FC was significantly associated with age. Further, the cingulum's SC and FC showed no relation. Different relationships between cognitive/motor performance and SC/FC separately were found, but no additive effect of the combined analysis of cingulum's SC and FC for predicting cognitive/motor performance was apparent. Hum Brain Mapp 37:855–867, 2016. © 2015 Wiley Periodicals, Inc .  相似文献   

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We studied the relationship between age‐related differences in inter‐ and intra‐hemispheric structural and functional connectivity in the bilateral motor network. Our focus was on the correlation between connectivity and declined motor performance in older adults. Structural and functional connectivity were estimated using diffusion weighted imaging and resting‐state electro‐encephalography, respectively. A total of 48 young and older healthy participants were measured. In addition, motor performances were assessed using bimanual coordination tasks. To pre‐select regions‐of‐interest (ROIs), a neural model was adopted that accounts for intra‐hemispheric functional connectivity between dorsal premotor area (PMd) and primary motor cortex (M1) and inter‐hemispheric connections between left and right M1 (M1L and M1R). Functional connectivity was determined via the weighted phase‐lag index (wPLI) in the source‐reconstructed beta activity during rest. We quantified structural connectivity using kurtosis anisotropy (KA) values of tracts derived from diffusion tensor‐based fiber tractography between the aforementioned areas. In the group of older adults, wPLI values between M1L–M1R were negatively associated with the quality of bimanual motor performance. The additional association between wPLI values of PMdL––M1L and PMdR–M1L supports that functional connectivity with the left hemisphere mediated (bimanual) motor control in older adults. The correlational analysis between the selected structural and functional connections revealed a strong association between wPLI values in the left intra‐hemispheric PMdL–M1L pathway and KA values in M1L–M1R and PMdR–M1L pathways in the group of older adults. This suggests that weaker structural connections in older adults correlate with stronger functional connectivity and, hence, poorer motor performance.  相似文献   

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目的 探讨青少年网络游戏成瘾者静息态下前扣带回功能连接的变化情况,从功能连接的角度解释前扣带回在网络游戏成瘾中的作用.方法 选择自2011年3月至10月在安徽医科大学附属省立医院心理门诊就诊的网络成瘾者17例为成瘾组,同期招募17例健康志愿者为正常对照组.对34例被试者一般情况进行了解并比较两组之间差异;成瘾组和正常对照组分别进行静息态fMRI扫描,数据采集后进行预处理,分别以左、右前扣带回为感兴趣脑区与全脑进行功能连接分析,比较成瘾组和正常对照组前扣带回功能连接的变化情况.结果 成瘾组每日或每周平均网络游戏时间及网络游戏渴求程度明显高于正常对照组,差异有统计学意义(P＜0.05);在静息态下,正常对照组与网络成瘾组的前扣带回都与前额叶、中后扣带回、伏核、中脑、颞叶及枕叶等脑区存在功能连接关系,与全脑其他脑区比较差异(体素差异)有统计学意义(P＜0.05);但与正常对照组比较,在静息态下成瘾组前扣带回与中脑、扣带回皮层、伏核及辅助运动区功能连接增强,与双侧前额叶、颞叶及枕叶功能连接减弱(P＜0.05).结论 网络游戏成瘾者前扣带回功能连接存在异常并可能与网络游戏成瘾的产生和维持有关.  相似文献   

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Age is accompanied by differences in the organization of functional brain networks, which impact behavior in adulthood. Functional networks become less segregated and more integrated with age. However, sex differences in network segregation declines with age are not well‐understood. Further, network segregation in the context of female reproductive stage is relatively understudied, though unmasking such relationships would be informative for elucidating biological mechanisms that contribute to sex‐specific differences in aging. In the current work, we used data from the Cambridge Centre for Ageing and Neuroscience (Cam‐CAN) repository to evaluate differences in resting‐state network segregation as a product of sex and reproductive stage. Reproductive stage was categorized using the Stages of Reproductive Aging Workshop (STRAW+10) criteria. Replicating prior work, we investigated the following functional networks: auditory, cerebellar‐basal ganglia, cingulo‐opercular task control, default mode, dorsal attention, fronto‐parietal task control, salience, sensory somatomotor mouth, sensory somatomotor hand, ventral attention, and visual. First, our results mirror findings from previous work indicating that network segregation is lower with increasing age. Second, when analyzing associations between network segregation and age within each sex separately, we find qualitative differences between females and males. Finally, we report significant effects of reproductive stage on network segregation, though these findings are likely driven by age. Broadly, our results suggest that impacts of sex may be important to evaluate when investigating network segregation differences across adulthood, though further work is needed to determine the unique role of menopause and sex hormones on the organization of functional brain networks within aging females.  相似文献   

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