Dynamic Connectivity Analysis Using Adaptive Window Size

Abstract

In this paper, we propose a new method to study and evaluate the time-varying brain network dynamics. The proposed RICI-imCPCC method (relative intersection of confidence intervals for the imaginary component of the complex Pearson correlation coefficient) is based on an adaptive window size and the imaginary part of the complex Pearson correlation coefficient. It reduces the weaknesses of the existing method of constant sliding window analysis with narrow and wide windows. These are the low temporal precision and low reliability for short connectivity periods for wide windows, and high susceptibility to noise for narrow windows, all resulting in low estimation accuracy. The proposed method overcomes these shortcomings by dynamically adjusting the window width using the RICI rule, which is based on the statistical properties of the area around the observed sample. In this paper, we compare the RICI-imCPCC with the existing constant sliding window analysis method and describe its advantages. First, the mathematical principles are established. Then, the comparison between the existing and the proposed method using synthetic and real electroencephalography (EEG) data is presented. The results show that the proposed RICI-imCPCC method has improved temporal resolution and estimation accuracy compared to the existing method and is less affected by the noise. The estimation error energy calculated for the RICI-imCPCC method on synthetic signals was lower by a factor of 1.22 compared to the error of the constant sliding window analysis using narrow window size imCPCC, by a factor of 2.87 compared to using wide window size imCPCC, by a factor of 6.69 compared to using narrow window size wPLI, and by a factor of 4.72 compared to using wide window size wPLI. Analysis of the real signals shows the ability of the proposed method to detect a P300 response and to detect a decrease in dynamic connectivity due to desynchronization and blockage of mu-rhythms.

EEG-Validated Photobiomodulation Treatment of Dementia—Case Study

“…In this work, we have chosen to use the connectivity measure imCPCC which was introduced in [ 36 , 37 ] and could replace wPLI for brain connectivity analysis. To evaluate the properties of the brain network (i.e., the network representing the connections between different brain areas), we used the graph-theoretic measure of global efficiency.…”

Bayesian Functional Connectivity and Graph Convolutional Network for Working Memory Load Classification

“…For each sliding window, the functional connectivity matrix using BSL is estimated. The sliding window is moved forward to estimate the functional connectivity [56], using the RICI algorithm [57]. Finally, the dynamic connectivity matrix of shape N*N*L is extracted.…”