Corneo-retinal-dipole and eyelid-related eye artifacts can be corrected offline and online in electroencephalographic and magnetoencephalographic signals

Reinmar J Kobler, Andreea I Sburlea, Catarina Lopes-Dias, Andreas Schwarz, Masayuki Hirata, Gernot R Müller-Putz*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Eye movements and blinks contaminate electroencephalographic (EEG) and magnetoencephalographic (MEG) activity. As the eye moves, the corneo-retinal dipole (CRD) and eyelid introduce potential/field changes in the M/EEG activity. These eye artifacts can affect a brain-computer interface and thereby impinge on neurofeedback quality. Here, we introduce the sparse generalized eye artifact subspace subtraction (SGEYESUB) algorithm that can correct these eye artifacts offline and in real time. We provide an open source reference implementation of the algorithm and the paradigm to obtain calibration data. Once the algorithm is fitted to calibration data (approx. 5 ​min), the eye artifact correction reduces to a matrix multiplication. We compared SGEYESUB with 4 state-of-the-art algorithms using M/EEG activity of 69 participants. SGEYESUB achieved the best trade-off between correcting the eye artifacts and preserving brain activity. Residual correlations between the corrected M/EEG channels and the eye artifacts were below 0.1. Error-related and movement-related cortical potentials were attenuated by less than 0.5 ​μV. Our results furthermore demonstrate that CRD and eyelid-related artifacts can be assumed to be stationary for at least 1-1.5 ​h, validating the feasibility of our approach in offline and online eye artifact correction.

Original languageEnglish
Article number117000
Publication statusPublished - Sept 2020


  • Brain-computer interface
  • Electroencephalography
  • Electrooculography
  • Event-related potential
  • Eye artifact
  • Magnetoencephalography

ASJC Scopus subject areas

  • Signal Processing
  • Neuroscience(all)
  • Biomedical Engineering
  • Neurology
  • Cognitive Neuroscience

Fields of Expertise

  • Human- & Biotechnology

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