ICA components for scalp EEG artefact removal


Hi everyone,

I am trying to clean some data using ICA artefact removal on a 128-channel scalp EEG data. I’ve been following several tutorials on Brainstorm, especially https://neuroimage.usc.edu/brainstorm/Tutorials/Epilepsy#Artifact_cleaning_with_ICA

I can not seem to find anything specific to how to choose an acceptable number for ICA components.
The minimal number of components required seems to depend on sampling rate, length (time window) of the file and the number of channels.

After doing some research on google, I’ve realised that this varies between different softwares so I was wondering if anyone has come across this information for Brainstorm?

Healthy Regards,

Do you mean: 1) the minimum possible value for the option "Number of ICA components" in the ICA process options window or 2) the minimum number of ICA that you can select or remove for cleaning for an artifact?

  1. Options "Number of ICA components":

    • maximum: the number of channels - if too high, the artifact can be split over multiple components
    • minimum: probably 2 - if too low, the artifact might not to be captured by any component
      There is no general rule here, as it depends mostly on the properties of the signal (SNR, complexity...)
  2. Component selection: no restriction, but you need to keep at least one, otherwise you don't have any signal left...