Thank you, Rick, for the quick response!
Re #3: I am running all 6 runs together. I can definitely try running 1 run at a time.
I was under the impression that I needed to do them all together so all the samples of the same category are present. Is that true? Or does it not matter since it is yielding individual regressors for each trial anyways?
Regarding the over modelling: Maybe I am approaching this all wrong? My goal was to get 3600 betas then run MVPA on the betas like the Brown tutorial suggests. Would this not work because the stim presentations were too short?
Again, thank you for your time, and I apologise in advance for novice questions!