Hi there, im recently learning Nilearn using preprocessed rest-fMRI data (fMRIprep).
From what i understand, GLM is to fit a theretical model to realistic BOLD signals according to stimulus onset.
Thats why im a bit confused by this page :
Default Mode Network extraction of ADHD dataset - Nilearn
If there is no stimulus at all (rest data), why do we need to do the GLM?
And they calculated frametimes and chose a HRF for GLM analysis, why is there HRF at all if the data is at rest…
im totally lost and any help would be greatly appreciated!!!