Dear Freesurfer Experts,

I have a very basic questions about creating subject-wise contrasts between runs

 

Background

Study with two runs per subject where each run corresponds two a different condition (i.e. Stimulation A (on - off) and Stimulation B (on - off).

I performed the preprocessing and 1st levels stats in the native subjects space

Questions

• How can I obtain a within-subjects contrast between two runs (the Stimulation A vs. Stimulation B )  obtained in two runs within one session?
• Can I obtain this within-subject contrast by staying in the native subject space?
• Do I have to concatenate both runs and create a new parradigm file?

Thanks for your support

Sincerely

Chris