Caulking the Leakage Effect in MEEG Source Connectivity Analysis

09/28/2018
by   Deirel Paz-Linares, et al.
0

Simplistic estimation of neural connectivity in MEEG sensor space is impossible due to volume conduction. The only viable alternative is to carry out connectivity estimation in source space. Among the neuroscience community this is claimed to be impossible or misleading due to Leakage: linear mixing of the reconstructed sources. To address this problematic we propose a novel solution method that caulks the Leakage in MEEG source activity and connectivity estimates: BC-VARETA. It is based on a joint estimation of source activity and connectivity in the frequency domain representation of MEEG time series. To achieve this, we go beyond current methods that assume a fixed gaussian graphical model for source connectivity. In contrast we estimate this graphical model in a Bayesian framework by placing priors on it, which allows for highly optimized computations of the connectivity, via a new procedure based on the local quadratic approximation under quite general prior models. A further contribution of this paper is the rigorous definition of leakage via the Spatial Dispersion Measure and Earth Movers Distance based on the geodesic distances over the cortical manifold. Both measures are extended for the first time to quantify Connectivity Leakage by defining them on the cartesian product of cortical manifolds. Using these measures, we show that BC-VARETA outperforms most state of the art inverse solvers by several orders of magnitude.

READ FULL TEXT

page 6

page 14

page 17

page 18

page 19

page 20

page 21

research
11/30/2020

The role of spectral complexity in connectivity estimation

The study of functional connectivity from magnetoecenphalographic (MEG) ...
research
11/28/2022

An Alphabet of Leakage Measures

We introduce a family of information leakage measures called maximal α,β...
research
09/23/2022

Multivariate Wasserstein Functional Connectivity for Autism Screening

Most approaches to the estimation of brain functional connectivity from ...
research
05/25/2018

Bayesian estimation for large scale multivariate Ornstein-Uhlenbeck model of brain connectivity

Estimation of reliable whole-brain connectivity is a crucial step toward...
research
02/22/2018

What's the Over/Under? Probabilistic Bounds on Information Leakage

Quantitative information flow (QIF) is concerned with measuring how much...

Please sign up or login with your details

Forgot password? Click here to reset