The two operations do completely different things.
- DC offset wrt baseline / sensor space: Removes the arbitrary baseline level the sensors might have in each trial (subtracts the baseline average)
Tutorials/Epoching - Brainstorm - Z-score of the min norm maps / source space: Normalizes the amplitude of each source wrt baseline in the condition averages (subtracts the average and divides by the std)
Tutorials/SourceEstimation - Brainstorm