Journal Article

Robust detrending, rereferencing, outlier detection, and inpainting for multichannel data

de Cheveigné, Alain, Arzounian, Dorothée

2018

Overview

Electroencephalography (EEG), magnetoencephalography (MEG) and related techniques are prone to glitches, slow drift, steps, etc., that contaminate the data and interfere with the analysis and interpretation. These artifacts are usually addressed in a preprocessing phase that attempts to remove them or minimize their impact. This paper offers a set of useful techniques for this purpose: robust detrending, robust rereferencing, outlier detection, data interpolation (inpainting), step removal, and filter ringing artifact removal. These techniques provide a less wasteful alternative to discarding corrupted trials or channels, and they are relatively immune to artifacts that disrupt alternative approaches such as filtering. Robust detrending allows slow drifts and common mode signals to be factored out while avoiding the deleterious effects of glitches. Robust rereferencing reduces the impact of artifacts on the reference. Inpainting allows corrupt data to be interpolated from intact parts based on the correlation structure estimated over the intact parts. Outlier detection allows the corrupt parts to be identified. Step removal fixes the high-amplitude flux jump artifacts that are common with some MEG systems. Ringing removal allows the ringing response of the antialiasing filter to glitches (steps, pulses) to be suppressed. The performance of the methods is illustrated and evaluated using synthetic data and data from real EEG and MEG systems. These methods, which are mainly automatic and require little tuning, can greatly improve the quality of the data. •Preprocessing is essential for EEG and MEG data analysis.•Robust methods for data preprocessing are not affected by glitches and artifacts.•Methods include robust detrending, rereferencing, inpainting and step removal.•These methods are effective and complementary with standard techniques such as ICA.

• Publisher: Elsevier Inc,Elsevier Limited,Elsevier,Academic Press
• Subject: Algorithms / Batch processing / Brain - physiology / Brain Mapping - methods / CCA / Cognitive science / CSP / Detrending / DSS / ECoG / EEG / Electrodes / Electroencephalography / Electroencephalography - methods / Humans / ICA / LFP / Magnetoencephalography / Magnetoencephalography - methods / MEG / Neuroscience / Robust statistics / Sensor noise / Signal Processing, Computer-Assisted / Skin / SNS / Weighted regression