Ear-EEG Sensitivity Modelling for Neural and Artifact Sources

TL;DR

This study models the sensitivity of ear-EEG configurations to neural sources in the brain and ocular artifacts, providing theoretical insights for its application in wearable neural monitoring.

Contribution

It offers a detailed theoretical analysis of ear-EEG sensitivity to neural and artifact sources, filling a gap in understanding its source-sensor relationship.

Findings

Ear-EEG effectively monitors neural activity from temporal lobes.

Ear-EEG's sensitivity to distant sources is limited but quantifiable.

Ocular artifacts significantly influence ear-EEG signals.

Abstract

The ear-EEG has emerged as a promising candidate for wearable brain monitoring in real-world scenarios. While experimental studies have validated ear-EEG in multiple scenarios, the source-sensor relationship for a variety of neural sources has not been established. In addition, a detailed theoretical analysis of the ear-EEG sensitivity to sources of artifacts is still missing. Within the present study, the sensitivity of various configurations of ear-EEG is established in the presence of neural sources from a range of brain surface locations, in addition to ocular sources for the blink, vertical saccade, and horizontal saccade eye movements which produce artifacts in the EEG signal. Results conclusively support the introduction of ear-EEG into conventional EEG paradigms for monitoring neural activity that originates from within the temporal lobes, while also revealing the extent to which ear-EEG can be used for sources further away from these regions. The use of ear-EEG for sources that are located further away from the ears is supported through the analysis of the prominence of ocular artifacts in ear-EEG. The results from this study can be used to support both existing and prospective experimental ear-EEG studies and applications in the context of both neural and ocular artifact sensitivity.