Graphical Structural Learning of rs-fMRI data in Heavy Smokers
Yiru Gong, Qimin Zhang, Huili Zheng, Zheyan Liu, Shaohan Chen
TL;DR
This work addresses how heavy smoking alters brain network topology by applying Gaussian Undirected Graphs to resting-state fMRI data from smokers and controls. The authors employ Graphical Lasso to estimate sparse precision matrices (with $K = \Sigma^{-1}$ and the estimator $\hat{K}^{gl}$ defined by $\hat{K}^{gl} = \arg\min_K\{ -\log\det(K) + \mathrm{tr}(SK) + \lambda \|K\|_1 \}$) and use Rotation Information Criterion to select the regularization parameter. Stability is assessed via bootstrap across multiple resamples, and graph similarity is quantified with Sorensen-Dice and node-wise Jaccard scores, revealing 50 regions with significant connectivity differences, notably Temporal_Inf_L, Thalamus_R, and Cerebelum_Crus2. When compared to non-graphical methods (ICA, PCA, GLMNET), the graphical approach better captures smoking-related brain connectivity changes, supporting its utility for high-dimensional neuroimaging data and offering insights for clinical research and smoking cessation strategies.
Abstract
Recent studies revealed structural and functional brain changes in heavy smokers. However, the specific changes in topological brain connections are not well understood. We used Gaussian Undirected Graphs with the graphical lasso algorithm on rs-fMRI data from smokers and non-smokers to identify significant changes in brain connections. Our results indicate high stability in the estimated graphs and identify several brain regions significantly affected by smoking, providing valuable insights for future clinical research.
