Heterogeneous source model for magnetoenecephalography

TL;DR

This paper introduces a heterogeneous source model for magnetoencephalography that combines localized and distributed sources to improve brain activity localization, demonstrated through numerical simulations.

Contribution

It presents a novel source model combining parametric and imaging approaches for MEG inverse problems, not previously used together.

Findings

Effective in numerical simulations

Separately identifies focal and background sources

Improves source localization accuracy

Abstract

In this paper, we propose a novel source model for a magnetoencephalography (MEG) inverse problem that combines a conventional extended parametric approach and an imaging approach.Our aim is to separately identify a focal current source and background activities spread over the brain.The new source model consists of two terms to represent different spatial characteristics: one is a localized patch source represented with a few parameters based on a mapping from a sphere to the cortex surface,and the other is a distributed source expressed using elemental dipoles on grid points on the cortical surface. We call it a heterogeneous source model, because these two models have not been used simultaneously.Effectiveness of the proposed method is shown via numerical simulations.