Independent Component Analysis on EEG

Independent Component Analysis (ICA) is often used to improve EEG signals. See blind source separation for the algorithm.

## 1. Selecting your channels

You typically will not want to do ICA on all 80 channels of your signal, some of which may not even be EEG channels. To create a smaller EEG with e.g. only the 64 scalp channels, use EEG: Extract channels.... From here on we will assume that your reduced EEG has 64 channels.

## 2. How to get a MixingMatrix

Once you have your reduced EEG, you can start to do ICA on it. This starts by creating a MixingMatrix: select your EEG object and choose To MixingMatrix.... The resulting MixingMatrix has one row for each of your 64 EEG channels, and columns called “ic1” through “ic64”.

## 3. How to see the independent components

Select your EEG and your MixingMatrix together and choose Unmix. The resulting ICA-EEG will have 64 channels called “ic1” through “ic64”.

## 4. Just checking back

If you select your ICA-EEG together with your MixingMatrix and choose Mix, the resulting EEG should be very similar to your original 64-channel EEG.

### Links to this page

- What was new in 6.1?