Towards automatic identification of independent components representing EEG artifacts

17 July 2012

Filipa Campos Viola Brain Products GmbH

Independent component analysis (ICA) is a blind source separation technique that allows the separation of linear mixtures of signals into maximal statistically independent sources, normally called independent components (ICs). This technique relies on several mathematical assumptions which need to be met by the signals of interest.

In the field of neurophysiologic signals ICA has been shown to be successful in disentangling multi-channel electroencephalogram (EEG) recordings into a number of artifacts and brain-related ICs. Thus this technique allows attenuating artifacts from EEG data by computing the back-projection of all ICs but those identified as representing artifact related activity. The categorization of ICs relies mainly on visual inspection, which makes it subjective and time consuming.

In this talk I will discuss the evaluation and optimization of EEG decompositions by means of ICA. I will also present semi-automatic procedures which improve the identification of ICs representing biological artifacts, and consequently facilitate the attenuation of these same artifacts from EEG recordings.



Filipa Campos Viola studied Biomedical Engineering at Instituto Superior Técnico, Lisbon, Portugal where she graduated in 2006. She joined Prof. Stefan Debener’s team at MRC - Institute of Hearing Research in Southampton, UK, in 2007. Her main research interest was auditory cortical plasticity in cochlear implant users. During her PhD project she developed tools to improve the attenuation of biological and electrical artifacts from EEG recordings by means of independent component analysis. This research was conducted later at the Biomagnetic Center, University Hospital Jena, Germany (2009-10) and at Dept. of Psychology, University of Oldenburg, Germany (2010-11). She was awarded her PhD (Dr. rer. nat.) in November 2011 from the University of Oldenburg, Germany. Since January 2012 she works as a Scientific Consultant in the Scientific Support team at Brain Products GmbH, Gilching, Germany.