Fast and effective removal of contamination from scalp electrical recordings

Abstract

Objective: To present a new, automated and fast artefact-removal approach which significantly reduces the effect of contamination in scalp electrical recordings.

Method: We used spectral and temporal characteristics of different sources recorded during a typical scalp electrical recording in order to improve a fast and effective artefact removal approach. Our experiments show that correlation coefficient and spectral gradient of brain components differ from artefactual components. We trained two binary support vector machine classifiers such that one separates brain components from muscle components, and the other separates brain components from mains power and environmental components. We compared the performance of the proposed approach with seven currently used alternatives on three datasets, measuring mains power artefact reduction, muscle artefact reduction and retention of brain neurophysiological responses.

Results: The proposed approach significantly reduces the main power and muscle contamination from scalp electrical recording without affecting brain neurophysiological responses. None of the competitors outperformed the new approach.

Conclusions: The proposed approach is the best choice for artefact reduction of scalp electrical recordings. Further improvements are possible with improved component analysis algorithms.

Significance: This paper provides a definitive answer to an important question: Which artefact removal algorithm should be used on scalp electrical recordings?

Keywords: Artefact removal; Canonical Correlation Analysis; Correlation coefficient; Scalp electrical recordings; Spectral gradient.