Schizophrenia is a severe mental disorder characterized by impaired perception, delusions, thought disorder, abnormal emotion regulation, altered motor function, and impaired drive. The default mode network （DMN）, s...Schizophrenia is a severe mental disorder characterized by impaired perception, delusions, thought disorder, abnormal emotion regulation, altered motor function, and impaired drive. The default mode network （DMN）, since it was first proposed in 2001, has become a central research theme in neuropsychiatric disorders, including schizophrenia. In this review, first we define the DMN and describe its functional activity, functional and anatomical connectivity, heritability, and inverse correlation with the task positive network. Second, we review empirical studies of the anatomical and functional DMN, and anti-correlation between DMN and the task positive network in schizophrenia. Finally, we review preliminary evidence about the relationship between antipsychotic medications and regulation of the DMN, review the role of DMN as a treatment biomarker for this disease, and consider the DMN effects of individualized therapies for schizophrenia.展开更多
To explore the brain default mode network(DMN)in patients with motor aphasia resulting from cerebral infarction,we used resting state functional magnetic resonance imaging(fMRI)to investigate the possible neural mecha...To explore the brain default mode network(DMN)in patients with motor aphasia resulting from cerebral infarction,we used resting state functional magnetic resonance imaging(fMRI)to investigate the possible neural mechanism.Thirteen patients with motor aphasia resulting from cerebral infarction and ten matched controls were selected in this study.All subjects were examined using resting state fMRI.We chose the posterior cingulate cortex as the region of interest and then used functional connectivity analysis to calculate the DMN functional connectivity and analyze differences in the functional connectivity between the two groups.Compared with normal controls,aphasia patient group showed a significantly decreased functional connectivity in bilateral medial frontal gyrus,superior frontal gyrus,middle frontal gyrus,middle temporal gyrus,precuneus and cuneus.The aphasia patient group showed increased functional connectivity mainly in bilateral medial frontal gyrus,middle frontal gyrus,inferior frontal gyrus,precentral gyrus,insula.The DMN in cerebral infarction motor aphasia patients showed significantly decreased functional connectivity in the resting state.The DMN most likely plays an important role in motor aphasia resulting from cerebral infarction.Furthermore,functional connectivity in the brain regions surrounding the left and right Broca’s areas was significantly enhanced due to compensatory mechanisms.This may be helpful for the recovery of language function in cerebral infarction patients with motor aphasia.展开更多
Functional magnetic resonance imaging studies have shown that the insular cortex has a signif- icant role in pain identification and information integration, while the default mode network is associated with cognitive...Functional magnetic resonance imaging studies have shown that the insular cortex has a signif- icant role in pain identification and information integration, while the default mode network is associated with cognitive and memory-related aspects of pain perception. However, changes in the functional connectivity between the defauk mode network and insula during pain remain unclear. This study used 3.0 T functional magnetic resonance imaging scans in 12 healthy sub- jects aged 24.8 ± 3.3 years to compare the differences in the functional activity and connectivity of the insula and default mode network between the baseline and pain condition induced by intramuscular injection of hypertonic saline. Compared with the baseline, the insula was more functionally connected with the medial prefrontal and lateral temporal cortices, whereas there was lower connectivity with the posterior cingulate cortex, precuneus and inferior parietal lobule in the pain condition. In addition, compared with baseline, the anterior cingulate cortex exhibited greater connectivity with the posterior insula, but lower connectivity with the anterior insula, during the pain condition. These data indicate that experimental low back pain led to dysfunction in the connectivity between the insula and default mode network resulting from an impairment of the regions of the brain related to cognition and emotion, suggesting the impor- tance of the interaction between these regions in pain processing.展开更多
AIM:To analyze changes in amplitude of low-frequency fluctuations(ALFFs)and default mode network(DMN)connectivity in the brain,using resting-state functional magnetic resonance imaging(rs-fMRI),in high myopia(HM)patie...AIM:To analyze changes in amplitude of low-frequency fluctuations(ALFFs)and default mode network(DMN)connectivity in the brain,using resting-state functional magnetic resonance imaging(rs-fMRI),in high myopia(HM)patients.METHODS:Eleven patients with HM(HM group)and 15 age-and sex-matched non-HM controls(non-HM group)were recruited.ALFFs were calculated and compared between HM group and non-HM group.Independent component analysis(ICA)was conducted to identify DMN,and comparisons between DMNs of two groups were performed.Region-of-interest(ROI)-based analysis was performed to explore functional connectivity(FC)between DMN regions.RESULTS:Significantly increased ALFFs in left inferior temporal gyrus(ITG),bilateral rectus gyrus(REC),bilateral middle temporal gyrus(MTG),left superior temporal gyrus(STG),and left angular gyrus(ANG)were detected in HM group compared with non-HM group(all P<0.01).HM group showed increased FC in the posterior cingulate gyrus(PCC)/precuneus(preCUN)and decreased FC in the left medial prefrontal cortex(mPFG)within DMN compared with nonHM group(all P<0.01).Compared with non-HM group,HM group showed higher FC between mPFG and bilateral middle frontal gyrus(MFG),ANG,and MTG(all P<0.01).In addition,HM patients showed higher FC between PCC/(preCUN)and the right cerebellum,superior frontal gyrus(SFG),left pre CUN,superior frontal gyrus(SFG),and medial orbital of the superior frontal gyrus(ORB supmed;all P<0.01).CONCLUSION:HM patients show different ALFFs and DMNs compared with non-HM subjects,which may imply the cognitive alterations related to HM.展开更多
The default mode network is associated with senior cognitive functions in humans. In this study, we performed independent component analysis of blood oxygenation signals from 14 heroin users and 13 matched normal cont...The default mode network is associated with senior cognitive functions in humans. In this study, we performed independent component analysis of blood oxygenation signals from 14 heroin users and 13 matched normal controls in the resting state through functional MRI scans. Results showed that the default mode network was significantly activated in the prefrontal lobe, posterior cingulated cortex and hippocampus of heroin users, and an enhanced activation signal was observed in the right inferior parietal Iobule （P 〈 0.05, corrected for false discovery rate）. Experimental findings indicate that the default mode network is altered in heroin users.展开更多
Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the u...Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field.展开更多
Acquired immune deficiency syndrome infection can lead to cognitive dysfunction represented by changes in the default mode network.Most recent studies have been cross-sectional and thus have not revealed dynamic chang...Acquired immune deficiency syndrome infection can lead to cognitive dysfunction represented by changes in the default mode network.Most recent studies have been cross-sectional and thus have not revealed dynamic changes in the default mode network following acquired immune deficiency syndrome infection and antiretroviral therapy.Specifically,when brain imaging data at only one time point are analyzed,determining the duration at which the default mode network is the most effective following antiretroviral therapy after the occurrence of acquired immune deficiency syndrome.However,because infection times and other factors are often uncertain,longitudinal studies cannot be conducted directly in the clinic.Therefore,in this study,we performed a longitudinal study on the dynamic changes in the default mode network over time in a rhesus monkey model of simian immunodeficiency virus infection.We found marked changes in default mode network connectivity in 11 pairs of regions of interest at baseline and 10 days and 4 weeks after virus inoculation.Significant interactions between treatment and time were observed in the default mode network connectivity of regions of interest pairs area 31/V6.R and area 8/frontal eye field(FEF).L,area 8/FEF.L and caudal temporal parietal occipital area(TPOC).R,and area 31/V6.R and TPOC.L.ART administered 4 weeks after infection not only interrupted the progress of simian immunodeficiency virus infection but also preserved brain function to a large extent.These findings suggest that the default mode network is affected in the early stage of simian immunodeficiency virus infection and that it may serve as a potential biomarker for early changes in brain function and an objective indicator for making early clinical intervention decisions.展开更多
Attentional issues may affect acquiring new information, task performance, and learning. Cortical network activities change during different functional brain states, including the default mode network (DMN) and attent...Attentional issues may affect acquiring new information, task performance, and learning. Cortical network activities change during different functional brain states, including the default mode network (DMN) and attention network. We investigated the neural mechanisms underlying attentional functions and correlations between DMN connectivity and attentional function using the Trail-Making Test (TMT)-A and -B. Electroencephalography recordings were performed by placing 19 scalp electrodes per the 10 - 20 system. The mean power level was calculated for each rest and task condition. Non-parametric Spearman’s rank correlation was used to examine the correlation in power levels between the rest and TMT conditions. The most significant correlations during TMT-A were observed in the high gamma wave, followed by theta and beta waves, indicating that most correlations were in the parietal lobe, followed by the frontal, central, and temporal lobes. The most significant correlations during TMT-B were observed in the beta wave, followed by the high and low gamma waves, indicating that most correlations were in the temporal lobe, followed by the parietal, frontal, and central lobes. Frontoparietal beta and gamma waves in the DMN may represent attentional functions.展开更多
Our conscious day-to-day self is often described as the “tip of the iceberg” of a much greater cognitive system. The edge of the water divides the phenomenal self from the sub/unconscious underlying it. Similar to a...Our conscious day-to-day self is often described as the “tip of the iceberg” of a much greater cognitive system. The edge of the water divides the phenomenal self from the sub/unconscious underlying it. Similar to an iceberg, the unconscious activity below the water vastly outweighs the conscious activity above it. What exactly lies beneath the surface of this murky water is a tantalizing topic of research and theory. The current research predominantly focuses on the physiology of the brain and the default mode network has been identified as an intrinsic mode of functioning. It is well known that autonomic nervous system sympathovagal balance orchestrated by the central autonomic network is strongly associated with modulation of cardiac, respiratory rate and other visceral physiological activity. In this article, we use existing research and a novel theory to tie together the default mode network, the autonomic nervous system, and non-neural physiology to describe a hypothesis on a greater biological system from which intrinsic brain activity may be founded. This hypothesis is that intrinsic brain activity and connectivities are significantly founded on activity of the body. We review how cardiorespiratory and other rhythms and electrical activity of the body may modulate and even underlie fundamental activity of the human brain and ultimately the mind. A more holistic biological system that could interface the brain and body via mechanisms such as neurovascular coupling would more accurately describe the nature of neural systems. Greater knowledge on the association and interface of brain and body via isomorphic physiologic counterparts to mind may carry profound implications in understanding intrinsic activity of the brain, consciousness, mind, and mental illness.展开更多
BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological s...BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.展开更多
BACKGROUND Group cognitive behavioral therapy(GCBT)is increasingly being used to treat obsessive-compulsive disorder(OCD)because of its high efficiency,economy,and interaction among group members.However,the changes i...BACKGROUND Group cognitive behavioral therapy(GCBT)is increasingly being used to treat obsessive-compulsive disorder(OCD)because of its high efficiency,economy,and interaction among group members.However,the changes in network functional connectivity(FC)in patients with OCD with GCBT remain unclear.AIM To investigate inter-and intra-network resting-state FC(rs-FC)abnormalities before and after GCBT in unmedicated patients with OCD and validate the efficacy of GCBT.METHODS Overall,33 individuals with OCD and 26 healthy controls underwent resting-state functional magnetic resonance imaging.The patients were rescanned 12 weeks after GCBT.Four cognition-related networks-default mode network(DMN),dorsal attention network(DAN),salience network(SAN),and frontoparietal network(FPN)-were selected to examine FC abnormalities within and between OCD networks before and after GCBT.Neuropsychological assessments including memory,executive function,speech,attention,and visuospatial ability were reassessed following GCBT.Pearson’s correlations were used to analyze the relationship between aberrant FC in cognition-related networks and altered neuropsychological assessments in patients.RESULTS Rs-FC within the DMN and DAN decreased significantly.Additionally,rs-FC between the DMN-DAN,DMNFPN,DMN-SAN,and DAN-SAN also decreased.Significant improvements were observed in cognitive functions,such as memory,executive function,attention,and visuospatial ability.Furthermore,reduced rs-FC within the DMN correlated with visuospatial ability and executive function;DAN positively correlated with Shape Trails Test(STT)-A test elapsed time;DMN-DAN negatively correlated with Rey-Osterrieth Complex Figure(Rey-O)mimicry time and the three elapsed times of the tower of Hanoi;DMN-SAN negatively correlated with Rey-O imitation time and positively correlated with STT-A test elapsed time;and DMN-FPN negatively correlated with Auditory Word Learning Test N1 and N4 scores.CONCLUSION Decreased rs-FC within the DMN and DAN,which correlated with executive function post-treatment,has potential as a neuroimaging marker to predict treatment response to GCBT in patients with OCD.展开更多
Emotion and executive control are often conceptualized as two distinct modes of human brain functioning.Little,however,is known about how the dynamic organization of large-scale functional brain networks that support ...Emotion and executive control are often conceptualized as two distinct modes of human brain functioning.Little,however,is known about how the dynamic organization of large-scale functional brain networks that support flexible emotion processing and executive control,especially their interactions.The amygdala and prefrontal systems have long been thought to play crucial roles in these processes.Recent advances in human neuroimaging studies have begun to delineate functional organization principles among the large-scale brain networks underlying emotion,executive control,and their interactions.Here,we propose a dynamic brain network model to account for interactive competition between emotion and executive control by reviewing recent resting-state and task-related neuroimaging studies using network-based approaches.In this model,dynamic interactions among the executive control network,the salience network,the default mode network,and sensorimotor networks enable dynamic processes of emotion and support flexible executive control of multiple processes;neural oscillations across multiple frequency bands and the locus coeruleus−norepinephrine pathway serve as communicational mechanisms underlying dynamic synergy among large-scale functional brain networks.This model has important implications for understanding how the dynamic organization of complex brain systems and networks empowers flexible cognitive and affective functions.展开更多
The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network mod...The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network model consisting of the default mode network(DMN), salience network(SN), and executive control network(ECN). The technique of voxel-mirrored homotopic connectivity(VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that:(1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions(i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions(i.e. frontoinsular cortex), and ECN-related brain regions(i.e. frontal middle gyrus and frontal inferior);(2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control(HC) groups, but no significant difference was observed between the a MCI and HC groups; and(3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination(MMSE) and Montreal Cognitive Scale(MOCA) scores and their factor scores in the AD, a MCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the a MCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.展开更多
The default mode network(DMN) is associated with the occurrence of mind-wandering or task-unrelated thought. In contrast, the frontal-parietal network(FPN) and visual network(VS) are involved in tasks with external st...The default mode network(DMN) is associated with the occurrence of mind-wandering or task-unrelated thought. In contrast, the frontal-parietal network(FPN) and visual network(VS) are involved in tasks with external stimuli. However, it is not clear how these functional network interactions support these two different processes– mind-wandering and on-task – especially with regard to individual variation in the mind-wandering experience. In this study, we investigated the functional connectivity and modular structure among the DMN, FPN, and VS. Our results showed that, compared to the on-task period, mindwandering was associated with increased DMN activity and increased DMN-VS connectivity. Moreover, mindwandering was accompanied by a large number of transitional nodes, which expressed a diversity of brain regions. Intriguingly, the functional connectivity of the FPN and VS was strongly correlated with individual behavioral performance. Our findings highlight the individual variation of mind-wandering, which implies the importance of other complementary large-scale brain networks.展开更多
Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlyi...Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlying neural substrates of creative thinking.The present study employs product-based creativity tasks that measure both originality and valuableness in an exploration of the dynamic relationship between the default mode(DMN),executive control(ECN),and salience(SN)networks through time windows.This methodology highlights relevance,or valuableness,in creativity evaluation as opposed to divergent thinking tasks solely measuring originality.The researchers identified seven brain regions belonging to the ECN,DMN,and SN as regions of interest(ROIs),as well as four representative seeds to analyze functional connectivity in 25 college student participants.Results showed that all of the identified ROIs were involved during the creative task.The insula,precuneus,and ventrolateral prefrontal cortex(vlPFC)remained active across all stages of product-based creative thinking.Moreover,the connectivity analyses revealed varied interaction patterns of DMN,ECN,and SN at different thinking stages.The integrated findings of the whole brain,ROI,and connectivity analyses suggest a trend that the DMN and SN(which relate to bottom-up thinking)attenuate as time proceeds,whereas the vlPFC(which relates to top-down thinking)gets stronger at later stages;these findings reflect the nature of our creativity tasks and decision-making of valuableness in later stages.Based on brain region activation throughout execution of the task,we propose that product-based creative process may include three stages:exploration and association,incubation and insight,and finally,evaluation and decision making.This model provides a thinking frame for further research and classroom instruction.展开更多
目的探讨精神分裂症患者药物治疗有应答与无应答者基线状态功能网络模块拓扑属性的差异。方法纳入首发未治疗精神分裂症患者,在接受标准化临床治疗4周后进行疗效评估,依据治疗前后阳性与阴性症状量表(positive and negative syndrome sc...目的探讨精神分裂症患者药物治疗有应答与无应答者基线状态功能网络模块拓扑属性的差异。方法纳入首发未治疗精神分裂症患者,在接受标准化临床治疗4周后进行疗效评估,依据治疗前后阳性与阴性症状量表(positive and negative syndrome scale,PANSS)评分的百分比变化,将患者分为应答组(45例)与无应答组(32例)。采集患者静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)图像,计算大脑功能网络模块化拓扑属性,比较应答组与无应答组功能连接的组间差异,分析各组患者网络模块功能连接与PANSS评分的相关性。结果与无应答组比较,应答组的模块性与平均节点参与系数升高,默认网络模块分离指数减低,感觉运动模块分离指数增高,视觉网络模块、感觉运动模块、灰质核团模块内连接降低,灰质核团-视觉模块、灰质核团-边缘模块、灰质核团-默认网络、灰质核团-感觉运动模块及感觉运动-默认网络模块间连接降低(FDR校正,P<0.05)。应答组灰质核团-默认网络(r=0.42,P<0.01)及感觉运动-默认网络(r=0.31,P=0.04)模块间连接分别与阳性症状评分呈正相关。受试者操作特征(receiver operating characteristic,ROC)曲线分析显示功能网络模块化连接具有良好的分类预测效能(AUC=0.858,95%CI:0.759~0.927)。结论灰质核团网络、默认网络及感觉运动网络的模块化连接可能为药物治疗精神分裂症的效果预测提供神经影像学证据。展开更多
慢性下腰痛(chronic low back pain,CLBP)作为全球致残率最高的肌肉骨骼疾病之一,其临床表现除持续性疼痛和运动功能障碍外,常伴随注意力缺陷、执行功能下降和工作记忆障碍等认知损害。多模态磁共振成像研究为阐明CLBP的神经机制提供了...慢性下腰痛(chronic low back pain,CLBP)作为全球致残率最高的肌肉骨骼疾病之一,其临床表现除持续性疼痛和运动功能障碍外,常伴随注意力缺陷、执行功能下降和工作记忆障碍等认知损害。多模态磁共振成像研究为阐明CLBP的神经机制提供了重要证据:功能磁共振成像(functional magnetic resonance imaging,fMRI)显示前额叶、扣带回和岛叶等认知控制脑区激活异常;静息态fMRI分析揭示默认模式网络、前额叶-顶叶控制网络及显著性网络功能连接失衡;弥散张量成像发现额叶-顶叶通路和胼胝体白质纤维完整性下降,且与认知测评表现相关;磁共振波谱提示N-乙酰天冬氨酸降低及谷氨酸/γ-氨基丁酸平衡失调,反映神经元功能和兴奋-抑制调节受损。现有证据支持CLBP通过“疼痛-情绪-认知”环路和三大脑网络失衡机制导致认知障碍。现有研究主要存在以下局限:大多数为横断面设计,无法确立因果关系;缺乏长期随访数据;样本代表性有限。基于这些局限,未来研究应当:(1)开展纵向追踪和干预性研究以验证神经机制与认知损害的因果关系;(2)整合多模态MRI技术与精细认知行为评估,建立CLBP认知损害的预测模型;(3)探索影像学生物标志物的临床转化价值,为早期识别和干预提供依据。通过解决这些问题,有望为改善CLBP患者的认知结局提供新思路。本综述系统梳理了CLBP相关认知损害的神经影像学研究进展,旨在为从事慢性疼痛与认知神经机制研究的科研人员及临床医生提供理论参考与研究思路,推动该领域从现象描述向机制探索与临床干预的转化。展开更多
基金supported by the National Natural Science Foundation of China(81271484,81471361,30900486,and 81371480)the National Basic Research Development Program(973 Program)of China(2012CB517904)the Nation Sponsored Study Abroad Program from China Scholarship Council(201506370095)
文摘Schizophrenia is a severe mental disorder characterized by impaired perception, delusions, thought disorder, abnormal emotion regulation, altered motor function, and impaired drive. The default mode network （DMN）, since it was first proposed in 2001, has become a central research theme in neuropsychiatric disorders, including schizophrenia. In this review, first we define the DMN and describe its functional activity, functional and anatomical connectivity, heritability, and inverse correlation with the task positive network. Second, we review empirical studies of the anatomical and functional DMN, and anti-correlation between DMN and the task positive network in schizophrenia. Finally, we review preliminary evidence about the relationship between antipsychotic medications and regulation of the DMN, review the role of DMN as a treatment biomarker for this disease, and consider the DMN effects of individualized therapies for schizophrenia.
文摘To explore the brain default mode network(DMN)in patients with motor aphasia resulting from cerebral infarction,we used resting state functional magnetic resonance imaging(fMRI)to investigate the possible neural mechanism.Thirteen patients with motor aphasia resulting from cerebral infarction and ten matched controls were selected in this study.All subjects were examined using resting state fMRI.We chose the posterior cingulate cortex as the region of interest and then used functional connectivity analysis to calculate the DMN functional connectivity and analyze differences in the functional connectivity between the two groups.Compared with normal controls,aphasia patient group showed a significantly decreased functional connectivity in bilateral medial frontal gyrus,superior frontal gyrus,middle frontal gyrus,middle temporal gyrus,precuneus and cuneus.The aphasia patient group showed increased functional connectivity mainly in bilateral medial frontal gyrus,middle frontal gyrus,inferior frontal gyrus,precentral gyrus,insula.The DMN in cerebral infarction motor aphasia patients showed significantly decreased functional connectivity in the resting state.The DMN most likely plays an important role in motor aphasia resulting from cerebral infarction.Furthermore,functional connectivity in the brain regions surrounding the left and right Broca’s areas was significantly enhanced due to compensatory mechanisms.This may be helpful for the recovery of language function in cerebral infarction patients with motor aphasia.
基金supported by the Science and Technology Foundation of Guangdong Province of China,No.2012B031800305
文摘Functional magnetic resonance imaging studies have shown that the insular cortex has a signif- icant role in pain identification and information integration, while the default mode network is associated with cognitive and memory-related aspects of pain perception. However, changes in the functional connectivity between the defauk mode network and insula during pain remain unclear. This study used 3.0 T functional magnetic resonance imaging scans in 12 healthy sub- jects aged 24.8 ± 3.3 years to compare the differences in the functional activity and connectivity of the insula and default mode network between the baseline and pain condition induced by intramuscular injection of hypertonic saline. Compared with the baseline, the insula was more functionally connected with the medial prefrontal and lateral temporal cortices, whereas there was lower connectivity with the posterior cingulate cortex, precuneus and inferior parietal lobule in the pain condition. In addition, compared with baseline, the anterior cingulate cortex exhibited greater connectivity with the posterior insula, but lower connectivity with the anterior insula, during the pain condition. These data indicate that experimental low back pain led to dysfunction in the connectivity between the insula and default mode network resulting from an impairment of the regions of the brain related to cognition and emotion, suggesting the impor- tance of the interaction between these regions in pain processing.
基金Supported by the National Natural Science Foundation of China(No.81870685)Beijing Natural Science Foundation(No.7172173)Key Laboratory of Myopia,Ministry of Health(Fudan University)(No.EENTM-15-01)。
文摘AIM:To analyze changes in amplitude of low-frequency fluctuations(ALFFs)and default mode network(DMN)connectivity in the brain,using resting-state functional magnetic resonance imaging(rs-fMRI),in high myopia(HM)patients.METHODS:Eleven patients with HM(HM group)and 15 age-and sex-matched non-HM controls(non-HM group)were recruited.ALFFs were calculated and compared between HM group and non-HM group.Independent component analysis(ICA)was conducted to identify DMN,and comparisons between DMNs of two groups were performed.Region-of-interest(ROI)-based analysis was performed to explore functional connectivity(FC)between DMN regions.RESULTS:Significantly increased ALFFs in left inferior temporal gyrus(ITG),bilateral rectus gyrus(REC),bilateral middle temporal gyrus(MTG),left superior temporal gyrus(STG),and left angular gyrus(ANG)were detected in HM group compared with non-HM group(all P<0.01).HM group showed increased FC in the posterior cingulate gyrus(PCC)/precuneus(preCUN)and decreased FC in the left medial prefrontal cortex(mPFG)within DMN compared with nonHM group(all P<0.01).Compared with non-HM group,HM group showed higher FC between mPFG and bilateral middle frontal gyrus(MFG),ANG,and MTG(all P<0.01).In addition,HM patients showed higher FC between PCC/(preCUN)and the right cerebellum,superior frontal gyrus(SFG),left pre CUN,superior frontal gyrus(SFG),and medial orbital of the superior frontal gyrus(ORB supmed;all P<0.01).CONCLUSION:HM patients show different ALFFs and DMNs compared with non-HM subjects,which may imply the cognitive alterations related to HM.
基金sponsored by a grant from the National Natural Science Foundation of China,No.30973084-C160801,C010604the Natural Science Foundation of Anhui Province,No.11040606M167
文摘The default mode network is associated with senior cognitive functions in humans. In this study, we performed independent component analysis of blood oxygenation signals from 14 heroin users and 13 matched normal controls in the resting state through functional MRI scans. Results showed that the default mode network was significantly activated in the prefrontal lobe, posterior cingulated cortex and hippocampus of heroin users, and an enhanced activation signal was observed in the right inferior parietal Iobule （P 〈 0.05, corrected for false discovery rate）. Experimental findings indicate that the default mode network is altered in heroin users.
文摘Medical procedures are inherently invasive and carry the risk of inducing pain to the mind and body.Recently,efforts have been made to alleviate the discomfort associated with invasive medical procedures through the use of virtual reality(VR)technology.VR has been demonstrated to be an effective treatment for pain associated with medical procedures,as well as for chronic pain conditions for which no effective treatment has been established.The precise mechanism by which the diversion from reality facilitated by VR contributes to the diminution of pain and anxiety has yet to be elucidated.However,the provision of positive images through VR-based visual stimulation may enhance the functionality of brain networks.The salience network is diminished,while the default mode network is enhanced.Additionally,the medial prefrontal cortex may establish a stronger connection with the default mode network,which could result in a reduction of pain and anxiety.Further research into the potential of VR technology to alleviate pain could lead to a reduction in the number of individuals who overdose on painkillers and contribute to positive change in the medical field.
基金supported by the National Natural Science Foundation of China,Nos.82271963(to HJL),81771806(to HJL),61936013(to HJL),82001914(to ZCT),81871511(to HZ)National Key R&D Program of China,No.2021YFA1301603(to ZCT)the Natural Science Foundation of Beijing,No.7212051(to HJL).
文摘Acquired immune deficiency syndrome infection can lead to cognitive dysfunction represented by changes in the default mode network.Most recent studies have been cross-sectional and thus have not revealed dynamic changes in the default mode network following acquired immune deficiency syndrome infection and antiretroviral therapy.Specifically,when brain imaging data at only one time point are analyzed,determining the duration at which the default mode network is the most effective following antiretroviral therapy after the occurrence of acquired immune deficiency syndrome.However,because infection times and other factors are often uncertain,longitudinal studies cannot be conducted directly in the clinic.Therefore,in this study,we performed a longitudinal study on the dynamic changes in the default mode network over time in a rhesus monkey model of simian immunodeficiency virus infection.We found marked changes in default mode network connectivity in 11 pairs of regions of interest at baseline and 10 days and 4 weeks after virus inoculation.Significant interactions between treatment and time were observed in the default mode network connectivity of regions of interest pairs area 31/V6.R and area 8/frontal eye field(FEF).L,area 8/FEF.L and caudal temporal parietal occipital area(TPOC).R,and area 31/V6.R and TPOC.L.ART administered 4 weeks after infection not only interrupted the progress of simian immunodeficiency virus infection but also preserved brain function to a large extent.These findings suggest that the default mode network is affected in the early stage of simian immunodeficiency virus infection and that it may serve as a potential biomarker for early changes in brain function and an objective indicator for making early clinical intervention decisions.
文摘Attentional issues may affect acquiring new information, task performance, and learning. Cortical network activities change during different functional brain states, including the default mode network (DMN) and attention network. We investigated the neural mechanisms underlying attentional functions and correlations between DMN connectivity and attentional function using the Trail-Making Test (TMT)-A and -B. Electroencephalography recordings were performed by placing 19 scalp electrodes per the 10 - 20 system. The mean power level was calculated for each rest and task condition. Non-parametric Spearman’s rank correlation was used to examine the correlation in power levels between the rest and TMT conditions. The most significant correlations during TMT-A were observed in the high gamma wave, followed by theta and beta waves, indicating that most correlations were in the parietal lobe, followed by the frontal, central, and temporal lobes. The most significant correlations during TMT-B were observed in the beta wave, followed by the high and low gamma waves, indicating that most correlations were in the temporal lobe, followed by the parietal, frontal, and central lobes. Frontoparietal beta and gamma waves in the DMN may represent attentional functions.
文摘Our conscious day-to-day self is often described as the “tip of the iceberg” of a much greater cognitive system. The edge of the water divides the phenomenal self from the sub/unconscious underlying it. Similar to an iceberg, the unconscious activity below the water vastly outweighs the conscious activity above it. What exactly lies beneath the surface of this murky water is a tantalizing topic of research and theory. The current research predominantly focuses on the physiology of the brain and the default mode network has been identified as an intrinsic mode of functioning. It is well known that autonomic nervous system sympathovagal balance orchestrated by the central autonomic network is strongly associated with modulation of cardiac, respiratory rate and other visceral physiological activity. In this article, we use existing research and a novel theory to tie together the default mode network, the autonomic nervous system, and non-neural physiology to describe a hypothesis on a greater biological system from which intrinsic brain activity may be founded. This hypothesis is that intrinsic brain activity and connectivities are significantly founded on activity of the body. We review how cardiorespiratory and other rhythms and electrical activity of the body may modulate and even underlie fundamental activity of the human brain and ultimately the mind. A more holistic biological system that could interface the brain and body via mechanisms such as neurovascular coupling would more accurately describe the nature of neural systems. Greater knowledge on the association and interface of brain and body via isomorphic physiologic counterparts to mind may carry profound implications in understanding intrinsic activity of the brain, consciousness, mind, and mental illness.
基金Supported by the Medical Research Project of the Chongqing Municipal Health Commission,No.2024WSJK110.
文摘BACKGROUND Currently,adolescent depression is one of the most significant public health concerns,markedly influencing emotional,cognitive,and social maturation.Despite advancements in distinguish the neurobiological substrates underlying depression,the intricate patterns of disrupted brain network connectivity in adolescents warrant further exploration.AIM To elucidate the neural correlates of adolescent depression by examining brain network connectivity using resting-state functional magnetic resonance imaging(rs-fMRI).METHODS The study cohort comprised 74 depressed adolescents and 59 healthy controls aged 12 to 17 years.Participants underwent rs-fMRI to evaluate functional connectivity within and across critical brain networks,including the visual,default mode network(DMN),dorsal attention,salience,somatomotor,and frontoparietal control networks.RESULTS Analyses revealed pronounced functional disparities within key neural circuits among adolescents with depression.The results demonstrated existence of hemispheric asymmetries characterized by enhanced activity in the left visual network,which contrasted the diminished activity in the right hemisphere.The DMN facilitated increased activity within the left prefrontal cortex and reduced engagement in the right hemisphere,implicating disrupted self-referential and emotional processing mechanisms.Additionally,an overactive right dorsal attention network and a hypoactive salience network were identified,underscoring significant abnormalities in attentional and emotional regulation in adolescent depression.CONCLUSION The findings from this study underscore distinct neural connectivity disruptions in adolescent depression,underscoring the critical role of specific neurobiological markers for precise early diagnosis of adolescent depression.The observed functional asymmetries and network-specific deviations elucidate the complex neurobiological architecture of adolescent depression,supporting the development of targeted therapeutic strategies.
基金Supported by the Pharmaceutical Science and Technology Project of Zhejiang Province,No.2023RC266the Natural Science Foundation of Ningbo,No.202003N4266.
文摘BACKGROUND Group cognitive behavioral therapy(GCBT)is increasingly being used to treat obsessive-compulsive disorder(OCD)because of its high efficiency,economy,and interaction among group members.However,the changes in network functional connectivity(FC)in patients with OCD with GCBT remain unclear.AIM To investigate inter-and intra-network resting-state FC(rs-FC)abnormalities before and after GCBT in unmedicated patients with OCD and validate the efficacy of GCBT.METHODS Overall,33 individuals with OCD and 26 healthy controls underwent resting-state functional magnetic resonance imaging.The patients were rescanned 12 weeks after GCBT.Four cognition-related networks-default mode network(DMN),dorsal attention network(DAN),salience network(SAN),and frontoparietal network(FPN)-were selected to examine FC abnormalities within and between OCD networks before and after GCBT.Neuropsychological assessments including memory,executive function,speech,attention,and visuospatial ability were reassessed following GCBT.Pearson’s correlations were used to analyze the relationship between aberrant FC in cognition-related networks and altered neuropsychological assessments in patients.RESULTS Rs-FC within the DMN and DAN decreased significantly.Additionally,rs-FC between the DMN-DAN,DMNFPN,DMN-SAN,and DAN-SAN also decreased.Significant improvements were observed in cognitive functions,such as memory,executive function,attention,and visuospatial ability.Furthermore,reduced rs-FC within the DMN correlated with visuospatial ability and executive function;DAN positively correlated with Shape Trails Test(STT)-A test elapsed time;DMN-DAN negatively correlated with Rey-Osterrieth Complex Figure(Rey-O)mimicry time and the three elapsed times of the tower of Hanoi;DMN-SAN negatively correlated with Rey-O imitation time and positively correlated with STT-A test elapsed time;and DMN-FPN negatively correlated with Auditory Word Learning Test N1 and N4 scores.CONCLUSION Decreased rs-FC within the DMN and DAN,which correlated with executive function post-treatment,has potential as a neuroimaging marker to predict treatment response to GCBT in patients with OCD.
基金supported by the National Natural Science Foundation of China(31920103009,32371104,and 32130045)the Major Project of National Social Science Foundation(20&ZD153)the Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(2023SHIBS0003).
文摘Emotion and executive control are often conceptualized as two distinct modes of human brain functioning.Little,however,is known about how the dynamic organization of large-scale functional brain networks that support flexible emotion processing and executive control,especially their interactions.The amygdala and prefrontal systems have long been thought to play crucial roles in these processes.Recent advances in human neuroimaging studies have begun to delineate functional organization principles among the large-scale brain networks underlying emotion,executive control,and their interactions.Here,we propose a dynamic brain network model to account for interactive competition between emotion and executive control by reviewing recent resting-state and task-related neuroimaging studies using network-based approaches.In this model,dynamic interactions among the executive control network,the salience network,the default mode network,and sensorimotor networks enable dynamic processes of emotion and support flexible executive control of multiple processes;neural oscillations across multiple frequency bands and the locus coeruleus−norepinephrine pathway serve as communicational mechanisms underlying dynamic synergy among large-scale functional brain networks.This model has important implications for understanding how the dynamic organization of complex brain systems and networks empowers flexible cognitive and affective functions.
基金Project supported by the National Natural Science Foundation of China(No.81771158)the Science Foundation of the Health Commission of Zhejiang Province(Nos.2016147373 and 2019321345),China
文摘The purpose of this study was to explore the differences in interhemispheric functional connectivity in patients with Alzheimer’s disease(AD) and amnestic mild cognitive impairment(aMCI) based on a triple network model consisting of the default mode network(DMN), salience network(SN), and executive control network(ECN). The technique of voxel-mirrored homotopic connectivity(VMHC) analysis was applied to explore the aberrant connectivity of all patients. The results showed that:(1) the statistically significant connections of interhemispheric brain regions included DMN-related brain regions(i.e. precuneus, calcarine, fusiform, cuneus, lingual gyrus, temporal inferior gyrus, and hippocampus), SN-related brain regions(i.e. frontoinsular cortex), and ECN-related brain regions(i.e. frontal middle gyrus and frontal inferior);(2) the precuneus and frontal middle gyrus in the AD group exhibited lower VMHC values than those in the aMCI and healthy control(HC) groups, but no significant difference was observed between the a MCI and HC groups; and(3) significant correlations were found between peak VMHC results from the precuneus and Mini Mental State Examination(MMSE) and Montreal Cognitive Scale(MOCA) scores and their factor scores in the AD, a MCI, and AD plus aMCI groups, and between the results from the frontal middle gyrus and MOCA factor scores in the a MCI group. These findings indicated that impaired interhemispheric functional connectivity was observed in AD and could be a sensitive neuroimaging biomarker for AD. More specifically, the DMN was inhibited, while the SN and ECN were excited. VMHC results were correlated with MMSE and MOCA scores, highlighting that VMHC could be a sensitive neuroimaging biomarker for AD and the progression from aMCI to AD.
基金supported by grants from the National Natural Science Foundation of China (31571111)the Chongqing Research Program of Basic Research and Frontier Technology (cstc2017jcyjAX0110)the Fundamental Research Funds for the Central Universities (SWU1609109)
文摘The default mode network(DMN) is associated with the occurrence of mind-wandering or task-unrelated thought. In contrast, the frontal-parietal network(FPN) and visual network(VS) are involved in tasks with external stimuli. However, it is not clear how these functional network interactions support these two different processes– mind-wandering and on-task – especially with regard to individual variation in the mind-wandering experience. In this study, we investigated the functional connectivity and modular structure among the DMN, FPN, and VS. Our results showed that, compared to the on-task period, mindwandering was associated with increased DMN activity and increased DMN-VS connectivity. Moreover, mindwandering was accompanied by a large number of transitional nodes, which expressed a diversity of brain regions. Intriguingly, the functional connectivity of the FPN and VS was strongly correlated with individual behavioral performance. Our findings highlight the individual variation of mind-wandering, which implies the importance of other complementary large-scale brain networks.
文摘Consensus of creativity research suggests that the measurement of both originality and valuableness is necessary when designing creativity tasks.However,few studies have emphasized valuableness when exploring underlying neural substrates of creative thinking.The present study employs product-based creativity tasks that measure both originality and valuableness in an exploration of the dynamic relationship between the default mode(DMN),executive control(ECN),and salience(SN)networks through time windows.This methodology highlights relevance,or valuableness,in creativity evaluation as opposed to divergent thinking tasks solely measuring originality.The researchers identified seven brain regions belonging to the ECN,DMN,and SN as regions of interest(ROIs),as well as four representative seeds to analyze functional connectivity in 25 college student participants.Results showed that all of the identified ROIs were involved during the creative task.The insula,precuneus,and ventrolateral prefrontal cortex(vlPFC)remained active across all stages of product-based creative thinking.Moreover,the connectivity analyses revealed varied interaction patterns of DMN,ECN,and SN at different thinking stages.The integrated findings of the whole brain,ROI,and connectivity analyses suggest a trend that the DMN and SN(which relate to bottom-up thinking)attenuate as time proceeds,whereas the vlPFC(which relates to top-down thinking)gets stronger at later stages;these findings reflect the nature of our creativity tasks and decision-making of valuableness in later stages.Based on brain region activation throughout execution of the task,we propose that product-based creative process may include three stages:exploration and association,incubation and insight,and finally,evaluation and decision making.This model provides a thinking frame for further research and classroom instruction.
文摘慢性下腰痛(chronic low back pain,CLBP)作为全球致残率最高的肌肉骨骼疾病之一,其临床表现除持续性疼痛和运动功能障碍外,常伴随注意力缺陷、执行功能下降和工作记忆障碍等认知损害。多模态磁共振成像研究为阐明CLBP的神经机制提供了重要证据:功能磁共振成像(functional magnetic resonance imaging,fMRI)显示前额叶、扣带回和岛叶等认知控制脑区激活异常;静息态fMRI分析揭示默认模式网络、前额叶-顶叶控制网络及显著性网络功能连接失衡;弥散张量成像发现额叶-顶叶通路和胼胝体白质纤维完整性下降,且与认知测评表现相关;磁共振波谱提示N-乙酰天冬氨酸降低及谷氨酸/γ-氨基丁酸平衡失调,反映神经元功能和兴奋-抑制调节受损。现有证据支持CLBP通过“疼痛-情绪-认知”环路和三大脑网络失衡机制导致认知障碍。现有研究主要存在以下局限:大多数为横断面设计,无法确立因果关系;缺乏长期随访数据;样本代表性有限。基于这些局限,未来研究应当:(1)开展纵向追踪和干预性研究以验证神经机制与认知损害的因果关系;(2)整合多模态MRI技术与精细认知行为评估,建立CLBP认知损害的预测模型;(3)探索影像学生物标志物的临床转化价值,为早期识别和干预提供依据。通过解决这些问题,有望为改善CLBP患者的认知结局提供新思路。本综述系统梳理了CLBP相关认知损害的神经影像学研究进展,旨在为从事慢性疼痛与认知神经机制研究的科研人员及临床医生提供理论参考与研究思路,推动该领域从现象描述向机制探索与临床干预的转化。
