Endogenous multifractal brain dynamics are modulated by age, cholinergic blockade and cognitive performance.
Endogenous multifractal brain dynamics are modulated by age, cholinergic blockade and cognitive performance.
复制标题
DOI：
10.1016/j.jneumeth.2008.06.037
复制
发表时间：
2008-09-30
影响因子：
3
通讯作者：
Bullmore, Edward T.
中科院分区：
文献类型：
--
作者：
Suckling, John;Wink, Alle Meije;Bernard, Frederic A.;Barnesa, Anna;Bullmore, Edward T.
健康有机体以规律的机械功能为特征的直觉观念受到了观察的挑战，即复杂性的丧失实际上表明了健康状况不佳。单分形简洁地描述了复杂的过程，并由与分形维数简单相关的单个时不变标度指数 H 控制。先前对静息 fMRI 时间序列的分析表明，衰老和东莨菪碱给药均与 H 的增加有关，并且先前编码任务中的更快响应也与 H 的增加有关。我们使用一种新颖的区域多重分形方法重新审视该实验，其中分形动力学假设为非平稳并由一系列局部奇点指数定义。该频谱的参数化能够折射年龄、东莨菪碱和任务表现的影响，并完善对相关信号变化的描述。使用相同的成像数据，我们还探索了湍流作为多重分形动力学的可能机制。有证据表明，卡斯坦的从高尺度到低尺度的湍流信息流模型的有效性有限，并且能量耗散的不变性可以通过临界相现象更好地解释，支持大脑维持自组织临界状态的命题。
The intuitive notion that a healthy organism is characterised by regular, mechanistic function has been challenged by observations that a loss complexity is, in fact, indicative of ill-health. Monofractals succinctly describe complex processes, and are controlled by a single time-invariant scaling exponent, H, simply related to the fractal dimension. A previous analysis of resting fMRI time-series demonstrated that ageing and scopolamine administration were both associated with increases in H and that faster response in a prior encoding task was also associated with increased H. We revisit this experiment with a novel regional, multifractal approach in which fractal dynamics are assumed non-stationary and defined by a spectrum of local singularity exponents. Parameterisation of this spectrum was capable of refracting the effects of age, scopolamine and task performance as well as a refining a description of the associated signal changes. Using the same imaging data, we also explored turbulence as a possible mechanism underlying multifractal dynamics. Evidence is provided that Carstaing’s model of turbulent information flow from high to low scales has only limited validity, and that invariance of energy dissipation is better explained by critical-phase phenomena, supporting the proposition that the brain maintains a state of self-organised criticality.
登录
查看更多内容
影响因子：
5.3
作者：
Achard, S;Salvador, R;Bullmore, ET
通讯作者：
Bullmore, ET
影响因子：
2.7
作者：
Chiu, Kuan-Ming;Chan, Hsiao-Lung;Lin, Tzu-Yu
通讯作者：
Lin, Tzu-Yu
影响因子：
8.6
作者：
BAK, P;TANG, C;WIESENFELD, K
通讯作者：
WIESENFELD, K
影响因子：
4.6
作者：
Kiyono, K;Struzik, ZR;Yamamoto, Y
通讯作者：
Yamamoto, Y
影响因子：
8.6
作者：
Kiyono, K;Struzik, ZR;Yamamoto, Y
通讯作者：
Yamamoto, Y