Hi Francois,
Following my analysis of ERPs I wanted to explore some of the differences between two groups found in the ERP analysis using source imaging. I could use feedback on my approach and the pipeline.
I used the default anatomy non-linear average of MNI 152 subjects. I computed the forward head models of the cortex surface using the Symmetric Boundary Element Method using default settings. For inverse modelling, I used sLORETA (minimum norm imaging and default setting parameters in Brainstorm (constrained source orientations, 3-dB signal-to-noise ratio, depth weighting and noise covariance regularization = 0.1). The noise covariance was calculated using the baseline period of the included trials. I created the sLORETA maps from the averaged trials per condition and for each subject and then rectified to absolute values. I then obtained the difference in sources (arithmetic average mean(A) - mean(B)) between groups. I ran another approach using Cortical density maps with otherwise the same settings. I rectified these to Z scores and looked at differences which in some cases were different from the prior approach.