为研究情绪重评时的大脑皮层源活动,针对情绪重评实验范式下采集的15例健康人同步EEG-fMRI数据,首先提出一种新颖的基于偶极子特征优化的融合源定位方法:根据fMRI加权最小范数估计源定位结果,采用20 ms EEG滑动时间窗,提取每个时窗内的...为研究情绪重评时的大脑皮层源活动,针对情绪重评实验范式下采集的15例健康人同步EEG-fMRI数据,首先提出一种新颖的基于偶极子特征优化的融合源定位方法:根据fMRI加权最小范数估计源定位结果,采用20 ms EEG滑动时间窗,提取每个时窗内的偶极子空间融合特征,将其作为动态融合先验进行加权最小范数估计溯源;随后将该结果与fMRI加权最小范数估计源定位结果进行情绪重评机制上的对比;最后采用样本熵进行脑电源复杂度分析。实验结果表明,该方法可以在高时间和空间分辨率下,有效地追踪情绪重评任务下大脑皮层上的脑电源动态并识别出相关脑区。情绪重评过程中,随着后枕顶叶晚期正电位的出现,显著活跃脑区从左顶叶下部、右侧额中回下部、左侧脑岛转移到右侧颞上回和左外侧枕叶,最后在晚期正电位慢波阶段激活了右侧梭状回、右侧额中回下部和右侧扣带回峡部(P<0.05)。通过脑电源样本熵的计算,提取出被试在接受不同情绪刺激后1500 ms内的显著脑区(P<0.05):情绪响应的活跃脑区为左外侧枕叶(负性:0.688±0.124,中性:0.590±0.126);情绪重评的活跃脑区为右侧额中回下部(负性重评:0.814±0.114,负性:0.736±0.123);情绪重评的抑制脑区为右侧颞上回(负性:0.642±0.152,负性重评:0.546±0.090)。这些结果为情绪重评相关的皮层脑电源定位研究提供了脑区参考。展开更多
探索相位同步和复杂网络方法在注意缺陷多动障碍(ADHD)脑网络机制研究中的应用,选取135例ADHD患者和102例正常对照作为研究对象。以这237例被试的功能磁共振图像时间序列作为研究数据,利用相位同步分析方法获得脑区间的连接关系,并在此...探索相位同步和复杂网络方法在注意缺陷多动障碍(ADHD)脑网络机制研究中的应用,选取135例ADHD患者和102例正常对照作为研究对象。以这237例被试的功能磁共振图像时间序列作为研究数据,利用相位同步分析方法获得脑区间的连接关系,并在此基础上构建脑网络。然后,利用复杂网络的局部效率指标评估静息态脑功能,并采用多元线性回归和方差分析等统计方法,分析ADHD患者和正常对照在静息态下脑区的局部效率可能存在的差异。结果表明,ADHD患者与正常对照在年龄、性别、量表分值(注意力和自制力)、3种智商值(语言智商、操作智商和总智商)等方面均无统计学差异,在诊断和头动参数上有显著差异(P<0.05,校正后)。诊断方面发现,11个局部效率正常对照组与ADHD组具有统计学差异的脑区(P<0.05),其中主要的脑区为左侧尾状核(0.118±0.317 vs 278±0.433)、丘脑(0.345±0.425 vs 0.541±0.435)、颞横回(0.467±0.476 vs 0.654±0.444)和右侧背外侧额上回(0.536±0.401 vs 0.681±0.333)、额中回(0.505±0.377vs 0.641±0.331)、尾状核(0.144±0.329 vs0.298±0.423)。在静息态下,ADHD患者和正常对照在左侧中央前回、尾状核、丘脑等脑区的局部效率差异可能与患者尾状核、丘脑等特定脑区的功能异常有关,也可能与患者注意和执行有关的神经网络损伤有关。展开更多
Background: Mild traumatic brain injury (mTBI) is one of the most common forms of cerebral pathology in young people and disorders involve dysfunctions in cognitive and motor spheres. We would like to examine the stru...Background: Mild traumatic brain injury (mTBI) is one of the most common forms of cerebral pathology in young people and disorders involve dysfunctions in cognitive and motor spheres. We would like to examine the structural and functional alterations of the brain in patients with mTBI while performing hand movements. Methods: Twenty healthy right-handed subjects (age 25.1 ± 3.9) and 10 patients (age 27.9 ± 7.3) with mTBI without hemiparesis participated in the study using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). FMRI and EEG reactions were analysed during right- and left-hand movements. Results: It was shown that fMRI reactive changes have a larger inter-individual variability of activation during left-hand movements in comparison with right-hand ones in healthy subjects. The TBI patients demonstrated an increase of a diffuse component of fMRI reactive changes compared to healthy people. A greater number of the brain structures was involved, mainly at the subcortical level, mostly in the left hemisphere during right-hand movement. EEG study demonstrated coherence changes for the slow (delta) frequency bands in the left hemisphere, while performing both hand movements. In healthy persons, EEG coherence changes were observed in the fast (alhpa2) frequency band predominantly in contralateral hemispheres, while performing hand movements. Conclusion: So, fMRI and EEG studies revealed the most expressed pathological reactive changes in the left hemisphere and the brain cortical structures during right-hand movements in patients after mTBI. These data allowed us to propose that the younger brain structures were the most sensitive to mTBI.展开更多
The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive...The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive study of cognitive brain function. In this paper, we record simultaneous EEG-fMRI of the same subject in emotional processing experiment in order to explore the characteristics of different emotional picture processing, and try to find the difference of the subjects' brain hemisphere while viewing different valence emotional pictures. The late positive potential(LPP) is a reliable electrophysiological index of emotional perception in humans. According to the analysis results, the slow-wave LPP and visual cortical blood oxygen level-dependent (BOLD) signals are both modulated by the rated intensity of picture arousal. The amplitude of the LPP correlate significantly with BOLD intensity in visual cortex, amygdala, temporal area, prefrontal and central areas across picture contents.展开更多
文摘为研究情绪重评时的大脑皮层源活动,针对情绪重评实验范式下采集的15例健康人同步EEG-fMRI数据,首先提出一种新颖的基于偶极子特征优化的融合源定位方法:根据fMRI加权最小范数估计源定位结果,采用20 ms EEG滑动时间窗,提取每个时窗内的偶极子空间融合特征,将其作为动态融合先验进行加权最小范数估计溯源;随后将该结果与fMRI加权最小范数估计源定位结果进行情绪重评机制上的对比;最后采用样本熵进行脑电源复杂度分析。实验结果表明,该方法可以在高时间和空间分辨率下,有效地追踪情绪重评任务下大脑皮层上的脑电源动态并识别出相关脑区。情绪重评过程中,随着后枕顶叶晚期正电位的出现,显著活跃脑区从左顶叶下部、右侧额中回下部、左侧脑岛转移到右侧颞上回和左外侧枕叶,最后在晚期正电位慢波阶段激活了右侧梭状回、右侧额中回下部和右侧扣带回峡部(P<0.05)。通过脑电源样本熵的计算,提取出被试在接受不同情绪刺激后1500 ms内的显著脑区(P<0.05):情绪响应的活跃脑区为左外侧枕叶(负性:0.688±0.124,中性:0.590±0.126);情绪重评的活跃脑区为右侧额中回下部(负性重评:0.814±0.114,负性:0.736±0.123);情绪重评的抑制脑区为右侧颞上回(负性:0.642±0.152,负性重评:0.546±0.090)。这些结果为情绪重评相关的皮层脑电源定位研究提供了脑区参考。
文摘探索相位同步和复杂网络方法在注意缺陷多动障碍(ADHD)脑网络机制研究中的应用,选取135例ADHD患者和102例正常对照作为研究对象。以这237例被试的功能磁共振图像时间序列作为研究数据,利用相位同步分析方法获得脑区间的连接关系,并在此基础上构建脑网络。然后,利用复杂网络的局部效率指标评估静息态脑功能,并采用多元线性回归和方差分析等统计方法,分析ADHD患者和正常对照在静息态下脑区的局部效率可能存在的差异。结果表明,ADHD患者与正常对照在年龄、性别、量表分值(注意力和自制力)、3种智商值(语言智商、操作智商和总智商)等方面均无统计学差异,在诊断和头动参数上有显著差异(P<0.05,校正后)。诊断方面发现,11个局部效率正常对照组与ADHD组具有统计学差异的脑区(P<0.05),其中主要的脑区为左侧尾状核(0.118±0.317 vs 278±0.433)、丘脑(0.345±0.425 vs 0.541±0.435)、颞横回(0.467±0.476 vs 0.654±0.444)和右侧背外侧额上回(0.536±0.401 vs 0.681±0.333)、额中回(0.505±0.377vs 0.641±0.331)、尾状核(0.144±0.329 vs0.298±0.423)。在静息态下,ADHD患者和正常对照在左侧中央前回、尾状核、丘脑等脑区的局部效率差异可能与患者尾状核、丘脑等特定脑区的功能异常有关,也可能与患者注意和执行有关的神经网络损伤有关。
文摘Background: Mild traumatic brain injury (mTBI) is one of the most common forms of cerebral pathology in young people and disorders involve dysfunctions in cognitive and motor spheres. We would like to examine the structural and functional alterations of the brain in patients with mTBI while performing hand movements. Methods: Twenty healthy right-handed subjects (age 25.1 ± 3.9) and 10 patients (age 27.9 ± 7.3) with mTBI without hemiparesis participated in the study using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). FMRI and EEG reactions were analysed during right- and left-hand movements. Results: It was shown that fMRI reactive changes have a larger inter-individual variability of activation during left-hand movements in comparison with right-hand ones in healthy subjects. The TBI patients demonstrated an increase of a diffuse component of fMRI reactive changes compared to healthy people. A greater number of the brain structures was involved, mainly at the subcortical level, mostly in the left hemisphere during right-hand movement. EEG study demonstrated coherence changes for the slow (delta) frequency bands in the left hemisphere, while performing both hand movements. In healthy persons, EEG coherence changes were observed in the fast (alhpa2) frequency band predominantly in contralateral hemispheres, while performing hand movements. Conclusion: So, fMRI and EEG studies revealed the most expressed pathological reactive changes in the left hemisphere and the brain cortical structures during right-hand movements in patients after mTBI. These data allowed us to propose that the younger brain structures were the most sensitive to mTBI.
基金The Open Project of the State Key Laboratory of Robotics and System at Harbin Institute of Technologygrant number:SKLRS-2010-2D-09,SKLRS-2010-MS-10+5 种基金National Natural Science Foundation of Chinagrant number:61201096Natural Science Foundation of Changzhou Citygrant number:CJ20110023Changzhou High-tech Reasearch Key Laboratory Projectgrant number:CM20123006
文摘The combination of electroencephalogram (EEG) and functional magnetic resonance imaging(fMRI) is a very attractive aim in neuroscience in order to achieve both high temporal and spatial resolution for the non-invasive study of cognitive brain function. In this paper, we record simultaneous EEG-fMRI of the same subject in emotional processing experiment in order to explore the characteristics of different emotional picture processing, and try to find the difference of the subjects' brain hemisphere while viewing different valence emotional pictures. The late positive potential(LPP) is a reliable electrophysiological index of emotional perception in humans. According to the analysis results, the slow-wave LPP and visual cortical blood oxygen level-dependent (BOLD) signals are both modulated by the rated intensity of picture arousal. The amplitude of the LPP correlate significantly with BOLD intensity in visual cortex, amygdala, temporal area, prefrontal and central areas across picture contents.
