Electroencephalogram Signal Correlations between Default Mode Network and Attentional Functioning

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.

The default mode network is affected in the early stage of simian immunodeficiency virus infection:a longitudinal study

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.

Resting-state connectivity in the default mode network and insula during experimental low back pain

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.

Altered amplitude of low-frequency fluctuations and default mode network connectivity in high myopia:a resting-state fMRI study

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.

Changes in the default mode network in the prefrontal lobe, posterior cingulated cortex and hippocampus of heroin users

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.

Application of virtual reality technology improves the functionality of brain networks in individuals experiencing pain

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.

From Biological Rhythms to the Default Mode Network: What Lies beneath the Tip of the Iceberg of Mind?

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.

静息态功能磁共振成像在血管性认知障碍患者默认网络研究中的应用进展

血管性认知障碍是由脑血管疾病导致的一种从轻度认知功能障碍至痴呆的综合征,由于缺乏敏感性和特异性生物标志物,早期不易鉴别和诊断。血管性认知障碍患者脑网络连接异常的脑区多位于默认网络,其异常变化的功能连接与患者的认知障碍程度相关。静息态功能磁共振成像技术是一种常用的检测静息态大脑内在活动的方法,应用静息态磁共振不同分析技术探索血管性认知障碍患者默认网络异常变化有助于深入研究血管性认知障碍的发病机制,并提供客观的影像依据。该文主要综述静息态功能磁共振成像技术在血管性认知障碍患者默认网络研究中的应用成果,为血管性认知障碍的精准诊断和评估提供新思路。

伴有童年创伤的重症抑郁患者异常全脑功能连接:一项静息态功能磁共振研究

【目的】童年创伤(CT)被认为是成年后发展为重度抑郁(MDD)的主要危险因素之一。然而,伴有CT的MDD(CT-MDD)患者的神经基础仍然知之甚少。因此,本研究的目的是探讨CT-MDD患者静息态全脑功能连接(FC)。【方法】对34名CT-MDD患者和34名健康对照组进行静息态功能磁共振扫描。进行全脑体素水平度中心性(DC)分析,选取两组间显著差异的脑区作为感兴趣区(ROI),进一步计算全脑FC。随后,将异常脑区DC,FC值与临床量表进行相关性分析。【结果】CT-MDD组右侧额中回(MFG)的DC值高于健康对照组。基于种子点的脑功能连接分析发现,与健康对照组相比,CT-MDD组右侧MFG与右内侧前额叶和左侧楔前叶之间的FC增加(P<0.05)。此外,右侧MFG的DC值与CT严重程度相关。【结论】我们的结果表明,以右侧MFG作为ROI,其与默认网络(DMN)中的两个重要脑区右内侧前额叶和左侧楔前叶之间的FC增加,这可能表明CT-MDD患者的认知执行网络与DMN之间的同步性增加。这些发现可能为深入了解CT-MDD的病理生理机制提供了见解。

重型抑郁障碍患者默认网络静态与动态功能连接变化

目的 基于静息态功能MRI(rs-fMRI)观察重型抑郁障碍(MDD)患者默认网络(DMN)静态与动态功能连接变化。方法 回顾性分析55例MDD患者(MDD组)及35名健康体检者(对照组)头颅高分辨率结构图像及rs-fMRI;以Matlab平台CONN工具箱进行图像预处理及独立成分分析(ICA)以提取DMN;比较组间DMN与全脑静态与动态功能连接变化;采用Pearson相关性分析观察MDD组与对照组存在差异脑区DMN与汉密尔顿抑郁量表-24项(HAMD-24)、汉密尔顿焦虑量表(HAMA)及韦氏智力测验评分的相关性。结果 相比对照组,MDD组DMN与丘脑、楔前叶及中央前回静态功能连接均减弱(P均<0.05);MDD组DMN与丘脑功能连接强度与HAMD-24评分呈低度负相关(r=-0.333,P=0.014)。相比对照组,MDD组DMN内侧前额叶皮层、左/右外侧顶叶与伏隔核,以及左外侧顶叶、后扣带回与丘脑动态功能连接均减弱。MDD组DMN内侧前额叶皮层-伏隔核、后扣带回-丘脑动态功能连接强度与HAMD-24评分呈低度正相关(r=0.313,P=0.019;r=0.311,P=0.021)。结论 MDD患者DMN与局部脑区存在静态与动态连接异常,部分与抑郁症严重程度相关。

默认网络和执行控制网络在运动改善老年人认知功能中的作用研究

目的:探讨运动对老年人默认网络和执行控制网络的影响,以及默认网络和执行控制网络在运动改善老年人认知功能中的作用。方法:选取北京老年脑健康促进计划(Beijing Aging Brain Rejuvenation Initiative,BABRI)数据库中34名老年人为研究对象,根据其运动频率分为运动组和对照组,其中运动组每周运动次数≥1次、每次运动时长>30 min、规律运动时间达1年以上,而对照组无运动习惯。采用简易精神状态量表(mini-mental state examination,MMSE)、画钟测验(clock drawing test,CDT)、符号数字模式测验(symbol digit modalities test,SDMT)、连线测验(trail making test,TMT)、词语流畅性测验(verbal fluency test,VFT)和波士顿命名测验(Boston naming test,BNT)分别评估老年人的总体认知能力、视空间能力、注意力、执行功能以及语言功能。采用功能性磁共振成像技术获取老年被试静息状态大脑活动,并通过独立成分分析获得默认网络和执行控制网络。最后对网络功能连接差异脑区与认知表现进行相关性分析。结果:1)运动组在MMSE、SDMT、TMT、VFT和BNT测验中的认知功能显著高于对照组,但两组CDT得分没有显著差异;2)运动组默认网络中背外侧额上回、左侧额上回中部、右侧前扣带回和额上回的功能连接与对照组相比显著增强;3)运动组执行控制网络中左侧下顶叶、左侧颞下回、额下回、左侧额上回内侧的功能连接与对照组相比显著增强;4)执行控制网络中左侧下顶叶与MMSE得分、SDMT得分呈显著正相关,与TMT-A、TMT-B连线时间呈显著负相关。结论:规律运动可以提高老年人的总体认知功能、注意力、执行功能和语言能力,运动对认知功能的改善可能与运动增强默认网络和执行控制网络中额叶、前扣带回和下顶叶的功能连接有关,下顶叶可能在其中发挥关键作用。

童年创伤影响社交焦虑障碍的心理与生物机制研究进展

社交焦虑障碍(social anxiety disorder,SAD)对个体的社会交往和正常生活具有显著负面影响,而童年创伤在SAD的发生发展中起着重要作用。童年创伤通过影响自我意识的发展,损害信息加工能力,阻碍前额叶-边缘系统环路和默认网络的正常发育,造成糖皮质激素和催产素的分泌异常等,导致个体在正确理解社交线索、合理调控情绪等方面存在困难,在社交情境中无法产生适应性情绪和行为反应,进而可能产生SAD。总之,童年创伤从心理和生理两个方面对社交功能产生持久的不良影响。

基于功能连接密度评估青少年男性网络游戏障碍患者脑功能损伤机制

目的为了评估网络游戏障碍脑功能损伤机制,本文应用基于半球内和半球间功能连接密度(functional connectivity density,FCD)的分析方法研究青少年男性网络游戏障碍患者脑区之间功能连接的异常改变。材料与方法对55名网络游戏障碍患者的静息状态功能磁共振图像和人口资料相匹配的50名健康对照者行全脑FCD的计算。再将全脑FCD分为同侧和对侧部分。采用双样本t检验比较网络游戏障碍组与健康对照组全脑、半球内和半球间FCD的差异。最后采用Pearson相关性分析探究网络游戏障碍患者全脑、半球内和半球间FCD值的变化与临床行为的相关性。结果网络游戏障碍组与健康对照组FCD的差异在全脑水平上主要分布于左侧楔前叶、左侧后扣带回与左侧颞中回。与健康对照组相比,网络游戏障碍患者在左侧楔前叶和左侧后扣带回中表现出半球间FCD的降低(t=-5.317、-3.556);此外,网络游戏障碍患者在左侧颞中回,左侧楔前叶与左侧后扣带回还表现出半球内FCD的降低(t=-5.044、-5.359、-4.183)(均体素水平P<0.005,团块水平P<0.05,高斯随机场校正)。结论网络游戏障碍患者在默认模式网络内存在半球内和半球间的功能连接异常。本研究将为网络游戏障碍患者的病理生理学机制和临床诊治提供新的见解。

阿尔茨海默病风险人群的超早期β淀粉样蛋白沉积与默认网络模式的关联研究

目的 探讨阿尔茨海默病风险人群的超早期脑脊液β淀粉样蛋白(Aβ)沉积与默认网络(DMN)功能连通性的关系。方法 纳入阿尔茨海默病神经影像学计划从2010年7月至2018年12月在北美地区招募的轻度认知障碍受试者,根据36个月随访期脑脊液Aβ的变化将受试者分为Aβ下降组(25例)和稳定组(19例)。运用脑功能MRI技术研究脑脊液Aβ下降、DMN功能连通性和认知功能变化的关系。结果 相较于Aβ稳定组,Aβ下降组在随访过程中连线测试-B(TMT-B)时间延长(P<0.05)。在双侧枕中回和左侧颞中回,Aβ下降组DMN功能连通性低于Aβ稳定组(P<0.01);其中,左侧颞中回的功能连通性与TMT-B时间呈负相关(r<0,P<0.05)。结论 超早期Aβ沉积与颞枕叶DMN功能连通性下降密切相关,且导致了执行功能损害。

基于部分定向相干的帕金森病默认模式网络脑电分析

目的:为了分析帕金森病患者大脑的默认模式网络(default mode network,DMN)潜在变化的原因和其临床特点的关系,以及探讨如何提取其脑电信号特征并对其进行准确有效地分类.方法:选择帕金森病患者和健康对照组各26名被试作为实验对象,将部分定向相干(partial directed coherence,PDC)应用于DMN相关电极的数据序列,获得对照组和帕金森病受试者的有效连接.通过统计分析后,得出6条具有显著差异的PDC连接,对它们进行深入讨论.进一步地,将这些连接值组成特征集并进行分类.结果:与对照组相比,帕金森病患者中有关注意力控制之间的连接降低,在涉及有关工作记忆的连接中,帕金森病相比于健康组患者的一些连接都有不同程度的增加.同时,使用XGBoost算法对特征集进行分类,得到76.5%的平均测试准确率.结论:静息状态下帕金森病患者的非运动症状与DMN网络存在显著性的关系,表现在注意力控制与记忆功能上,这与DMN中BA区的受损有很大的关系.随后对两类受试者的分类也验证了PDC算法用于DMN分析的有效性,为帕金森病人的测试和预防提供了一种新途径.

肝豆状核变性患者默认模式网络变化及模型构建

目的:基于独立成分分析(ICA),探讨肝豆状核变性(WD)患者默认模式网络(DMN)功能连接(FC)的改变及其与临床神经精神特征之间的关系。方法:将2021年1月-2021年12月在本院就诊的85例肝豆状核变性患者和年龄、性别相匹配的85例健康志愿者(HC组)纳入本研究。对每例被试采用统一肝豆状核变性评分量表(UWDRS)进行评估,包括神经功能症状(UWDRS-N)和精神症状(UWDRS-P)评分,并根据UWDRS评分将患者分为神经精神症状重度组(>10分)和轻度组(≤10分)。使用3.0T磁共振BOLD序列采集静息态fMRI数据,采用ICA方法提取DMN内各体素的FC值,并在HC组与WD组之间进行比较,对有差异脑区的FC值与临床量表评分进行Pearson相关性分析。以DMN内所有体素的FC值为特征变量采用支持向量机(SVM)的方法构建分类模型,包括正常组与WD组以及轻度与重度WD组。结果:与对照组比较,WD组的DMN内表现出广泛的FC值减低,包括前默认模式网络(aDMN)内的左内侧前额叶皮层(L_MPFC)和左侧前扣带回(L_ACC),以及后DMN(pDMN)内的左侧角回(L_ANG)、楔前叶(PCUN)、左侧顶下小叶(L_IPG)和左侧后扣带回(L_PCC)。aDMN内的L_MPFC、L_ACC和pDMN内的PCUN的FC值与UWDRS-N评分呈负相关,aDMN内的L_MPFC、L_PCC和pDMN内的L_IPG的FC值与UWDRS-P评分呈负相关。采用SVM构建的二分类器,在鉴别WD与HC组时的符合率为80.23%,AUC为0.865;在鉴别轻度与重度WD组的符合率为70.89%,AUC为0.723。结论:WD患者的默认模式网络中存在广泛的功能连接减低,其可能是导致患者出现神经精神症状(如高阶认知障碍)的潜在神经病理机制。基于DMN的FC值构建的SVM分类器可提高对WD疾病及其病情转归的评估效能。

基于默认模式网络探讨针刺治疗失眠症过度觉醒机制的研究进展

过度觉醒模型是解释失眠症(insomnia disorder,ID)发生和维持的重要理论之一,然而少有研究探索ID过度觉醒的影像学机制。研究发现,ID患者常表现出情绪异常、记忆障碍等过度觉醒症状,这些症状与默认模式网络(default mode network,DMN)功能异常密切相关,故DMN损害可能是ID发病机制之一。针刺可能通过调节DMN的活动及功能连接变化,抑制大脑过度觉醒状态,进而改善ID症状。本文将从分子基因、神经内分泌、心率变异性、多导睡眠图及影像学等角度系统梳理ID过度觉醒机制,探索过度觉醒与DMN的关系,综合针刺调控ID患者过度觉醒的影像学证据,通过分析过度觉醒与DMN的联系,为针刺干预ID机制研究提供影像学证据,并为未来研究方向提供思路,如从脑网络连接和神经元细胞层面探索,扩大样本量,采用多模态成像技术,并结合新兴分析方法,以更全面地揭示针刺治疗ID的脑效应机制。

基于动脉自旋标记的睡眠剥夺大脑血流灌注特点

目的探讨睡眠剥夺与正常睡眠状态下大脑血流灌注特点的差异。资料与方法2020年10月—2021年12月在西安市各高校中招募50例受试者。使用精神运动警觉性任务(PVT)收集持续性注意力行为学数据。采用动脉自旋标记技术比较睡眠剥夺后与正常睡眠后的相对脑血流量(rCBF),分析两种状态下差异脑区的rCBF与PVT脱漏频次差值的相关性。结果与正常睡眠后相比,睡眠剥夺后双侧背外侧前额叶、双侧顶上小叶、左侧眶部额中回、双侧颞中回、右侧中央后回、双侧角回的血流灌注显著减低,而双侧丘脑、左侧楔前叶、右侧内侧前额叶、左侧后扣带回、左侧颞下回的血流灌注明显增高(FDR校正,P<0.05,团块大小≥20体素)。左侧背外侧前额叶及右侧顶上小叶的rCBF变化与PVT脱漏频次差值呈负相关(r=-0.56,P<0.001;r=-0.64,P<0.001),左侧楔前叶的rCBF变化与PVT脱漏频次差值呈正相关(r=0.72,P<0.001)。结论默认网络、额顶网络及丘脑相关脑区血流灌注异常改变可能是睡眠剥夺后持续性注意力下降的重要神经机制。

基于默认网络内部功能连接能预测抑郁症患者睡眠障碍因子分

目的探究抑郁症(major depression disorder,MDD)患者大脑默认网络(default mode network,DMN)功能连接(functional connectivity,FC)能否预测其睡眠障碍因子分。材料与方法基于REST-meta-MDD公开数据集中满足本实验需求的326例MDD被试静息态功能磁共振成像数据。采用Power模板在全脑中定义了264个脑区节点,分别获取患者的DMN内部FC和DMN与其他网络间的外部FC。采用基于连接组的预测模型在发现数据集上分别基于DMN内部和DMN外部FC对MDD患者的睡眠障碍因子分进行回归预测,独立验证集上检验模型的稳定性。结果在DMN内部FC,发现数据集对MDD患者的睡眠障碍因子分具有一定的预测性(r=0.244,P<0.001),外部独立验证集也有很好的泛化预测效果(r=0.345,P=0.046)。DMN外部FC在发现数据集上对其可进行预测(r=0.238,P<0.001),而独立验证集其泛化性能不足(r=0.256,P=0.143)。结论DMN内部FC对MDD患者睡眠障碍因子分具有一定的预测性。

The Dynamic Relationship of Brain Networks Across Time Windows During Product-Based Creative Thinking

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.