1. Population shrinkage of covariance (PoSCE) for better individual brain functional-connectivity estimation
- Author
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Bertrand Thirion, Mehdi Rahim, Gaël Varoquaux, Modelling brain structure, function and variability based on high-field MRI data (PARIETAL), Service NEUROSPIN (NEUROSPIN), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), ANR-11-BINF-0004,NiConnect,Outils pour la Recherche Clinique par cartographie de la connectivité cérébrale fonctionnelle(2011), European Project: 785907,H2020,HBP SGA2(2018), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Service NEUROSPIN (NEUROSPIN), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
- Subjects
Computer science ,Rest ,Population ,population models ,Twins ,Health Informatics ,Positive-definite matrix ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Estimation of covariance matrices ,0302 clinical medicine ,[STAT.ML]Statistics [stat]/Machine Learning [stat.ML] ,[INFO.INFO-IM]Computer Science [cs]/Medical Imaging ,Connectome ,Image Processing, Computer-Assisted ,Statistics::Methodology ,Humans ,Radiology, Nuclear Medicine and imaging ,education ,Shrinkage ,education.field_of_study ,Models, Statistical ,Radiological and Ultrasound Technology ,Covariance ,[SCCO.NEUR]Cognitive science/Neuroscience ,Siblings ,functional connectivity ,Probabilistic logic ,Age Factors ,Estimator ,Reproducibility of Results ,Computer Graphics and Computer-Aided Design ,Magnetic Resonance Imaging ,[STAT]Statistics [stat] ,shrinkage ,Phenotype ,Population model ,Computer Vision and Pattern Recognition ,Algorithm ,030217 neurology & neurosurgery ,Algorithms - Abstract
International audience; Estimating covariances from functional Magnetic Resonance Imaging at rest (r-fMRI) can quantify interactions between brain regions. Also known as brain functional connectivity, it reflects inter-subject variations in behavior and cognition, and characterizes neuropathologies. Yet, with noisy and short time-series, as in r-fMRI, covariance estimation is challenging and calls for penalization, as with shrinkage approaches. We introduce population shrinkage of covariance estimator (PoSCE) : a covariance estimator that integrates prior knowledge of covariance distribution over a large population, leading to a non-isotropic shrinkage. The shrinkage is tailored to the Riemannian geometry of symmetric positive definite matrices. It is coupled with a probabilistic modeling of the individual and population covariance distributions. Experiments on two large r-fMRI datasets (HCP n=815, Cam-CAN n=626) show that PoSCE has a better bias-variance trade-off than existing covariance estimates: this estimator relates better functional-connectivity measures to cognition while capturing well intra-subject functional connectivity.
- Published
- 2018