Quantum mechanics

Artifact (error)

Philosophy

Psychiatry

Power (physics)

Set (abstract data type)

Magnetoencephalography

Computer science

Simple (philosophy)

Filter (signal processing)

Physics

Spatial filter

Psychology

Pattern recognition (psychology)

Mathematics

Image (mathematics)

Data set

Epistemology

Artificial intelligence

Geometry

Electroencephalography

Programming language

Noise (video)

Line (geometry)

Computer vision

NeuroImage

Power line artifacts are the bane of animal and human electrophysiology. A number of methods are available to help attenuate or eliminate them, but each has its own set of drawbacks. In this brief note I present a simple method that combines the advantages of spectral and spatial filtering, while minimizing their downsides. A perfect-reconstruction filterbank is used to split the data into two parts, one noise-free and the other contaminated by line artifact. The artifact-contaminated stream is processed by a spatial filter to project out line components, and added to the noise-free part to obtain clean data. This method is applicable to multichannel data such as electroencephalography (EEG), magnetoencephalography (MEG), or multichannel local field potentials (LFP). I briefly review past methods, pointing out their drawbacks, describe the new method, and evaluate the outcome using synthetic and real data.

ZapLine: A simple and effective method to remove power line artifacts