The Effect of Prior Parameters on Standardized Kalman Filter-Based EEG Source Localization

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Prasikala, Dilshanie, Lahtinen, Joonas, Koulouri, Alexandra, Pursiainen, Sampsa
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908473796591616
author Prasikala, Dilshanie
Lahtinen, Joonas
Koulouri, Alexandra
Pursiainen, Sampsa
author_facet Prasikala, Dilshanie
Lahtinen, Joonas
Koulouri, Alexandra
Pursiainen, Sampsa
contents EEG Source localization is a critical tool in neuroscience, with applications ranging from epilepsy diagnosis to cognitive research. It involves solving an ill-posed inverse problem that lacks a unique solution unless constrained by prior knowledge. The Bayesian framework enables the incorporation of such knowledge, typically encoded through prior models. Various algorithms have been proposed for source localization, and they differ significantly in how prior knowledge is incorporated. Some approaches rely on anatomical or functional constraints, while others use statistical distributions or sampling-based techniques. In this landscape, the Standardized Kalman Filter (SKF) represents a dynamic Bayesian approach that integrates temporal modeling with a Gaussian prior structure. It addresses the depth bias, a common limitation in source localization, through a post-hoc standardization step that equalizes sensitivity across cortical depths and makes deep activity detection feasible. This study focuses on the development and optimization of Gaussian prior models within the SKF framework for simultaneous cortical and sub-cortical activity detection. Synthetic data similar to the P20 / N20 component of the somatosensory evoked potentials (SEP) was used to identify effective prior parameter configurations for reconstructing both deep and superficial sources under different noise levels. We also investigated the role of RTS smoothing in enhancing source separability. Our results indicate that raising the standardization exponent to 1.25, along with smoothing, significantly improves depth localization accuracy at low noise levels.
format Preprint
id arxiv_https___arxiv_org_abs_2507_23450
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Effect of Prior Parameters on Standardized Kalman Filter-Based EEG Source Localization
Prasikala, Dilshanie
Lahtinen, Joonas
Koulouri, Alexandra
Pursiainen, Sampsa
Numerical Analysis
EEG Source localization is a critical tool in neuroscience, with applications ranging from epilepsy diagnosis to cognitive research. It involves solving an ill-posed inverse problem that lacks a unique solution unless constrained by prior knowledge. The Bayesian framework enables the incorporation of such knowledge, typically encoded through prior models. Various algorithms have been proposed for source localization, and they differ significantly in how prior knowledge is incorporated. Some approaches rely on anatomical or functional constraints, while others use statistical distributions or sampling-based techniques. In this landscape, the Standardized Kalman Filter (SKF) represents a dynamic Bayesian approach that integrates temporal modeling with a Gaussian prior structure. It addresses the depth bias, a common limitation in source localization, through a post-hoc standardization step that equalizes sensitivity across cortical depths and makes deep activity detection feasible. This study focuses on the development and optimization of Gaussian prior models within the SKF framework for simultaneous cortical and sub-cortical activity detection. Synthetic data similar to the P20 / N20 component of the somatosensory evoked potentials (SEP) was used to identify effective prior parameter configurations for reconstructing both deep and superficial sources under different noise levels. We also investigated the role of RTS smoothing in enhancing source separability. Our results indicate that raising the standardization exponent to 1.25, along with smoothing, significantly improves depth localization accuracy at low noise levels.
title The Effect of Prior Parameters on Standardized Kalman Filter-Based EEG Source Localization
topic Numerical Analysis
url https://arxiv.org/abs/2507.23450