Dear group:
I would be grateful if someone could explain how the delayed
boxcar model works. We use SPM96 in Medx.
Namely, what is the hemodynamic delay assumed (6 seconds?) with the
delayed boxcar model?
If the delay is 6 seconds, does the z-test comparing active and rest
tasks just ignore the scans at less than 6 seconds and compare scans
after 6 seconds in active to those after 6 seconds in rest?
Is there some kind of true curve fitting going on in
determining the z-scores on the resulting statistical maps?
Any help would be greatly appreciated.
Thanks
Jeff Lorberbaum
Medical University of South Carolina
|