Resting-State Functional Connectivity Dynamics in Healthy Aging: An Approach Through Network Change Point Detection

2020 ◽  
Vol 10 (3) ◽  
pp. 134-142
Author(s):  
Núria Mancho-Fora ◽  
Marc Montalà-Flaquer ◽  
Laia Farràs-Permanyer ◽  
David Bartrés-Faz ◽  
Lídia Vaqué-Alcázar ◽  
...  
2020 ◽  
Vol 20 (3) ◽  
pp. 200-212
Author(s):  
Núria Mancho-Fora ◽  
Marc Montalà-Flaquer ◽  
Laia Farràs-Permanyer ◽  
Daniel Zarabozo-Hurtado ◽  
Geisa Bearitz Gallardo-Moreno ◽  
...  

2020 ◽  
Author(s):  
Andreas Anastasiou ◽  
Ivor Cribben ◽  
Piotr Fryzlewicz

Evidence of the non stationary behavior of functional connectivity (FC) networks has been observed in task based functional magnetic resonance imaging (fMRI) experiments and even prominently in resting state fMRI data. This has led to the development of several new statistical methods for estimating this time-varying connectivity, with the majority of the methods utilizing a sliding window approach. While computationally feasible, the sliding window approach has several limitations. In this paper, we circumvent the sliding window, by introducing a statistical method that finds change-points in FC networks where the number and location of change-points are unknown a priori. The new method, called cross-covariance isolate detect (CCID), detects multiple change-points in the second-order (cross-covariance or network) structure of multivariate, possibly high-dimensional time series. CCID allows for change-point detection in the presence of frequent changes of possibly small magnitudes, can assign change-points to one or multiple brain regions, and is computationally fast. In addition, CCID is particularly suited to task based data, where the subject alternates between task and rest, as it firstly attempts isolation of each of the change-points within subintervals, and secondly their detection therein. Furthermore, we also propose a new information criterion for CCID to identify the change-points. We apply CCID to several simulated data sets and to task based and resting state fMRI data and compare it to recent change-point methods. CCID is also applicable to electroencephalography (EEG), magentoencephalography (MEG) and electrocorticography (ECoG) data. Similar to other biological networks, understanding the complex network organization and functional dynamics of the brain can lead to profound clinical implications. Finally, the R package ccid implementing the method from the paper is available from GitHub.


2021 ◽  
Vol 15 ◽  
Author(s):  
Jaehee Kim ◽  
Woorim Jeong ◽  
Chun Kee Chung

To study the dynamic nature of brain activity, functional magnetic resonance imaging (fMRI) data is useful including some temporal dependencies between the corresponding neural activity estimates. Recent studies have shown that the functional connectivity (FC) varies according to time and location which should be incorporated into the model. Modeling this dynamic FC (DFC) requires time-varying measures of spatial region of interest (ROI) sets. To know about the DFC, change-point detection in FC is of particular interest. In this paper, we propose a method of detecting a change-point based on the maximum of eigenvalues via random matrix theory (RMT). From covariance matrices for FC of all ROI's, the temporal change-point of FC is decided by an RMT approach. Simulation results show that our proposed method can detect meaningful FC change-points. We also illustrate the effectiveness of our FC detection approach by applying our method to epilepsy data where change-points detected are explained by the changes in memory capacity. Our study shows the possibility of RMT based approach in DFC change-point problem and in studying the complex dynamic pattern of functional brain interactions.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1889-P
Author(s):  
ALLISON L.B. SHAPIRO ◽  
SUSAN L. JOHNSON ◽  
BRIANNE MOHL ◽  
GRETA WILKENING ◽  
KRISTINA T. LEGGET ◽  
...  

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