Dynamic spatiotemporal variability of alpha-BOLD relationships during the resting-state and task-evoked responses
Dynamic spatiotemporal variability of alpha-BOLD relationships during the resting-state and task-evoked responses
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DOI：
10.1016/j.neuroimage.2017.04.051
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发表时间：
2017-07
期刊：
影响因子：
5.7
通讯作者：
Stephen D. Mayhew;A. Bagshaw
中科院分区：
文献类型：
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作者：
Stephen D. Mayhew;A. Bagshaw
准确表征神经元活动的两个最突出的神经成像测量，8-13 Hz，枕顶EEG α振荡和BOLD fMRI信号之间的时空关系，必须包括α功率和脑功能的内在动力学性质。在这里，在睁眼休息状态下，我们使用16 s滑动窗口分析，并证明动态alpha-BOLD相关性的平均空间网络与6分钟内计算的静态网络高度可比。然而，alpha-BOLD相关性显示出受试者内的大量时空变异性，并通过许多不同的配置，使得静态网络仅在16秒时期的~10%中完全表示，视觉和顶叶区域（平均一致）通常彼此或与α相反地相关。我们发现，静态α BOLD相关性的共同假设大大简化了大脑网络动态的时间变化。波动在alpha-BOLD耦合显着依赖于α功率的瞬时幅度，和主要和侧视觉区最强烈的负相关与α在不同的α功率状态，可能表明多种α机制的作用。动态alpha-BOLD相关性不能用眨眼/运动、头部运动或非神经元生理变异性来解释。个体的平均α功率和频率被发现有助于受试者之间的变异性α-BOLD相关性。此外，应用程序的视觉刺激数据集表明，动态α-BOLD相关性提供了有关大脑的刺激反应的功能信息，表现出时空波动相关的变化，在试验的试验BOLD响应幅度。与大响应试验相比，在小振幅BOLD响应试验之前和之后都发现视觉α-BOLD相关性显着较弱。
Accurate characterization of the spatiotemporal relationship between two of the most prominent neuroimaging measures of neuronal activity, the 8–13 Hz, occipito-parietal EEG alpha oscillation and the BOLD fMRI signal, must encompass the intrinsically dynamic nature of both alpha power and brain function. Here, during the eyes-open resting state, we use a 16 s sliding-window analysis and demonstrate that the mean spatial network of dynamic alpha-BOLD correlations is highly comparable to the static network calculated over six minutes. However, alpha-BOLD correlations showed substantial spatiotemporal variability within-subjects and passed through many different configurations such that the static network was fully represented in only ~10% of 16 s epochs, with visual and parietal regions (coherent on average) often opposingly correlated with each other or with alpha. We find that the common assumption of static-alpha BOLD correlations greatly oversimplifies temporal variation in brain network dynamics. Fluctuations in alpha-BOLD coupling significantly depended upon the instantaneous amplitude of alpha power, and primary and lateral visual areas were most strongly negatively correlated with alpha during different alpha power states, possibly suggesting the action of multiple alpha mechanisms. Dynamic alpha-BOLD correlations could not be explained by eye-blinks/movements, head motion or non-neuronal physiological variability. Individual's mean alpha power and frequency were found to contribute to between-subject variability in alpha-BOLD correlations. Additionally, application to a visual stimulation dataset showed that dynamic alpha-BOLD correlations provided functional information pertaining to the brain's response to stimulation by exhibiting spatiotemporal fluctuations related to variability in the trial-by-trial BOLD response magnitude. Significantly weaker visual alpha-BOLD correlations were found both preceding and following small amplitude BOLD response trials compared to large response trials.