Process2 tab and Baseline normalization

[Joakim96]

Hello forum!

We have questions about Process2 tab's Standardize algorithm "Baseline normalization". We would like to know how does it work and what does it do to our data. When we Run command, we often get couple of very high-peaking channels also when we use the completely same file as A and B. If someone could kindly explain the basic working principal behind Baseline normalization that would help us a lot.

Thank you already,

~Joakim96 & Termu

[Francois]

It depends which option you are using.

• DC offset correction: it is equivalent to process "Preprocess > Remove DC offset".
  Tutorials/Epoching - Brainstorm
• Z-score transformation: used in our standard processing pipeline to normalize minimum norm source maps:
  Tutorials/SourceEstimation - Brainstorm
• Event-related perturbation (ERS/ERD): Common for normalizing time-frequency maps:
  Tutorials/TimeFrequency - Brainstorm

If you get very high values for some channels, it is because the value that you divide your by is close to zero... Which may indicate a very clean averaged signal or a no signal at all during your baseline.

Note that on sensor data, it is not advised to run anything else but the "Remove DC offset" option.

[Joakim96]

@Francois Thank you for your fast reply!