It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the ...It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the assessment of irreversibility in brain networks can provide valuable insights into their non-equilibrium properties.In this study,we utilized an open-source whole-brain functional magnetic resonance imaging(fMRI)dataset from both resting and task states to evaluate the irreversibility of large-scale human brain networks.Our analysis revealed that the brain networks exhibited significant irreversibility,violating detailed balance,and generating entropy.Notably,both physical and cognitive tasks increased the extent of this violation compared to the resting state.Regardless of the state(rest or task),interactions between pairs of brain regions were the primary contributors to this irreversibility.Moreover,we observed that as global synchrony increased within brain networks,so did irreversibility.The first derivative of irreversibility with respect to synchronization peaked near the phase transition point,characterized by the moderate mean synchronization and maximized synchronization entropy of blood oxygenation level-dependent(BOLD)signals.These findings deepen our understanding of the non-equilibrium dynamics of large-scale brain networks,particularly in relation to their phase transition behaviors,and may have potential clinical applications for brain disorders.展开更多
脑卒中后吞咽障碍是脑卒中患者常见的并发症,发生率高达30%~65%^([1-2])。吞咽困难会让患者同时遭遇营养不良与吸入性肺炎的严峻挑战,还影响其生活品质与康复进程^([3-4])。近年来,功能磁共振成像(functional magnetic resonance imagin...脑卒中后吞咽障碍是脑卒中患者常见的并发症,发生率高达30%~65%^([1-2])。吞咽困难会让患者同时遭遇营养不良与吸入性肺炎的严峻挑战,还影响其生活品质与康复进程^([3-4])。近年来,功能磁共振成像(functional magnetic resonance imaging,fMRI)技术的快速发展为研究脑卒中后吞咽障碍的神经机制提供了新的视角。fMRI能够无创观察大脑活动,揭示吞咽过程中不同脑区的激活模式和功能连接变化^([5])。展开更多
目的 基于静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)探讨重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗前后的酒精使用障碍(alcohol use disorder,AUD)患者冲动...目的 基于静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)探讨重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗前后的酒精使用障碍(alcohol use disorder,AUD)患者冲动行为脑网络改变。方法 选取2022年12月至2024年12月于我院就诊的AUD患者为AUD组,同时选取同期在我院进行体检的健康者为对照组,每组初始计划纳入61例。根据纳排标准,AUD组和对照组分别排除15例,最终两组各纳入46例。通过SPSS23.0软件进行数据分析。运用双重差分(DID)模型评估效果。结果 两组患者BIS-Ⅱ总评分和RBANS总评分均比干预前有明显下降(P<0.05)。State1状态下,AUD组DMN和ECN间功能连接以增强为主;state2状态下,DMN和ECN间功能连接以减弱为主。AUD组state2状态平均持续时间与冲动行为评分呈负相关、与认知功能评分呈正相关(P<0.05)。结论 rs-fMRI发现,rTMS治疗后的AUD患者,其冲动行为相关脑区中DMN和ECN的动态功能连接模式发生改变,该连接可反映大脑活动的瞬时变化,为AUD画着精准诊疗提供临床依据。展开更多
为弥补传统的广义线性模型(generalized linear model,GLM)方法的不足,并探索模式识别在运动脑科学当中的应用价值。使用支持向量机(support vector machine,SVM)模式识别算法,以低频振幅(fractional amplitude of low-frequency fluctu...为弥补传统的广义线性模型(generalized linear model,GLM)方法的不足,并探索模式识别在运动脑科学当中的应用价值。使用支持向量机(support vector machine,SVM)模式识别算法,以低频振幅(fractional amplitude of low-frequency fluctuations,fALFF)、局部一致性(regional homogeneity,ReHo)和度中心度(degree centrality,DC)作为学习特征,对射击运动组和滑冰运动组(分类1)、射击运动组和对照组(分类2)以及速滑运动组和对照组(分类3)之间进行二分类,并计算每一个脑区在分类算法当中的权重。使用留一交叉验证法计算分类正确率,使用总的准确率、接受者操作特性曲线(receiver operating characteristic curve,ROC)、以及预测准确率来衡量机器分类算法的优劣性。结果表明:分类1中SVM算法的正确率较高且分类效果更稳定,总的准确率(total accuracy,tACC)可以维持在96.67%以上,曲线下面积(area under curve,AUC)均为1,说明SVM算法对区分不同项目运动员脑静息态功能特征时更有优势;在分类2和分类3中,SVM算法效果取决于使用的指标。其中,使用fALFF或者综合使用三个静息态指标的分类效果较稳定(tACC均在80%以上,AUC均在0.88以上);小脑在分类1算法中占较多的权重,提示不同运动项目运动员的脑功能活动之间差异最明显的部位主要在小脑上。而分类2和3中,除了小脑,还有一些与运动执行和控制及其他功能活动相关的脑区参与了算法的构成。通过SVM分类算法的应用获得较为理想的结果,展示了模式识别方法在运动科学领域的应用价值。研究成果有助于体育科学研究者从新的角度更加全面地理解运动与脑的关系。展开更多
The activity of occipitotemporal regions involved in linguistic reading processes,such as the ventral occipitotemporal cortex(vOT),is believed to exhibit strong interactions during higher-order language processing,spe...The activity of occipitotemporal regions involved in linguistic reading processes,such as the ventral occipitotemporal cortex(vOT),is believed to exhibit strong interactions during higher-order language processing,specifically in the connectivity between the occipital gyrus and the temporal gyrus.In this study,we utilized functional magnetic resonance imaging(fMRI)with psychophysiological interaction(PPI)and dynamic causal modeling(DCM)to investigate the functional and effective connectivity in the occipitotemporal network during speed reading.We conducted the experiment with native Japanese speakers who underwent and without speed-reading training and subsequently performed established reading tasks at different speeds(slow,medium,and fast)while undergoing 3-Tesla Siemens fMRI.Our activation analyses revealed significant changes in occipital and temporal regions as reading speed increased,indicating functional connectivity within the occipitotemporal network.DCM results further demonstrated more intricate effective connections and high involvement within the occipitotemporal pathway:(1)reading signals originated from the inferior occipital gyrus(iO),distributed to the vOT and the posterior superior temporal sulcus(pSTS),and then gathered in the anterior superior temporal sulcus(aSTS);(2)reading speed loads had modulation effects on the pathways from the aSTS to vOT and from the iO to vOT.These findings highlight the complex connectivity and dynamic interactions within the occipitotemporal network during speed-reading processes.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(Grant Nos.lzujbky-2021-62 and lzujbky-2024-jdzx06)the National Natural Science Foundation of China(Grant No.12247101)+1 种基金the Natural Science Foundation of Gansu Province,China(Grant Nos.22JR5RA389 and 23JRRA1740)the‘111 Center’Fund(Grant No.B20063).
文摘It has been argued that the human brain,as an information-processing machine,operates near a phase transition point in a non-equilibrium state,where it violates detailed balance leading to entropy production.Thus,the assessment of irreversibility in brain networks can provide valuable insights into their non-equilibrium properties.In this study,we utilized an open-source whole-brain functional magnetic resonance imaging(fMRI)dataset from both resting and task states to evaluate the irreversibility of large-scale human brain networks.Our analysis revealed that the brain networks exhibited significant irreversibility,violating detailed balance,and generating entropy.Notably,both physical and cognitive tasks increased the extent of this violation compared to the resting state.Regardless of the state(rest or task),interactions between pairs of brain regions were the primary contributors to this irreversibility.Moreover,we observed that as global synchrony increased within brain networks,so did irreversibility.The first derivative of irreversibility with respect to synchronization peaked near the phase transition point,characterized by the moderate mean synchronization and maximized synchronization entropy of blood oxygenation level-dependent(BOLD)signals.These findings deepen our understanding of the non-equilibrium dynamics of large-scale brain networks,particularly in relation to their phase transition behaviors,and may have potential clinical applications for brain disorders.
文摘脑卒中后吞咽障碍是脑卒中患者常见的并发症,发生率高达30%~65%^([1-2])。吞咽困难会让患者同时遭遇营养不良与吸入性肺炎的严峻挑战,还影响其生活品质与康复进程^([3-4])。近年来,功能磁共振成像(functional magnetic resonance imaging,fMRI)技术的快速发展为研究脑卒中后吞咽障碍的神经机制提供了新的视角。fMRI能够无创观察大脑活动,揭示吞咽过程中不同脑区的激活模式和功能连接变化^([5])。
文摘目的 基于静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)探讨重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗前后的酒精使用障碍(alcohol use disorder,AUD)患者冲动行为脑网络改变。方法 选取2022年12月至2024年12月于我院就诊的AUD患者为AUD组,同时选取同期在我院进行体检的健康者为对照组,每组初始计划纳入61例。根据纳排标准,AUD组和对照组分别排除15例,最终两组各纳入46例。通过SPSS23.0软件进行数据分析。运用双重差分(DID)模型评估效果。结果 两组患者BIS-Ⅱ总评分和RBANS总评分均比干预前有明显下降(P<0.05)。State1状态下,AUD组DMN和ECN间功能连接以增强为主;state2状态下,DMN和ECN间功能连接以减弱为主。AUD组state2状态平均持续时间与冲动行为评分呈负相关、与认知功能评分呈正相关(P<0.05)。结论 rs-fMRI发现,rTMS治疗后的AUD患者,其冲动行为相关脑区中DMN和ECN的动态功能连接模式发生改变,该连接可反映大脑活动的瞬时变化,为AUD画着精准诊疗提供临床依据。
基金Japan Society for the Promotion of Science(21K15614)National Natural Science Foundation of China(62103404)Chinese Academy of Sciences President’s International Fellowship Initiative(2022VBA0031).
文摘The activity of occipitotemporal regions involved in linguistic reading processes,such as the ventral occipitotemporal cortex(vOT),is believed to exhibit strong interactions during higher-order language processing,specifically in the connectivity between the occipital gyrus and the temporal gyrus.In this study,we utilized functional magnetic resonance imaging(fMRI)with psychophysiological interaction(PPI)and dynamic causal modeling(DCM)to investigate the functional and effective connectivity in the occipitotemporal network during speed reading.We conducted the experiment with native Japanese speakers who underwent and without speed-reading training and subsequently performed established reading tasks at different speeds(slow,medium,and fast)while undergoing 3-Tesla Siemens fMRI.Our activation analyses revealed significant changes in occipital and temporal regions as reading speed increased,indicating functional connectivity within the occipitotemporal network.DCM results further demonstrated more intricate effective connections and high involvement within the occipitotemporal pathway:(1)reading signals originated from the inferior occipital gyrus(iO),distributed to the vOT and the posterior superior temporal sulcus(pSTS),and then gathered in the anterior superior temporal sulcus(aSTS);(2)reading speed loads had modulation effects on the pathways from the aSTS to vOT and from the iO to vOT.These findings highlight the complex connectivity and dynamic interactions within the occipitotemporal network during speed-reading processes.
