P 220. Why do we need methods for removing artifacts from TMS-evoked EEG data?

• Published in: Clinical neurophysiology Vol. 124; no. 10; pp. e169 - e170
• Main Authors: Hernandez-Pavon, J.C, Metsomaa, J, Stenroos, M, Sarvas, J, Ilmoniemi, R
• Format: Journal Article
• Language: English
• Published: Elsevier Ireland Ltd 01-10-2013
• Subjects: Neurology
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2013.04.297

Transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) is a powerful tool for studying cortical excitability and connectivity. In this study, TMS-EEG is used to study different brain areas. Despite the fact that there are many ways to reduce the artifacts from the EEG signals, it is still very challenging to record EEG data free from artifacts, especially when lateral areas are stimulated, e.g., language areas, or visual areas. The problems that produce the artifacts are described in detail. In this presentation I will present two approaches to deal with large artifacts. One of the approaches consists of developing methods to remove artifacts by using independent component analysis (ICA). The second approach presents methods for suppressing the artifacts rather than removing them. The methods are tested with real and simulated data. The results show that these techniques are promising in removing and suppressing artifacts, allowing one to study artifactual areas of the human brain with TMS-EEG. These methods combined with source localization open possibilities for studying functional connectivity and brain mapping of artifactual areas.