Dear Spmers,
I would like to check if the following procedure to remove movement
effects on fMRI serie data is correct:
A multiple regression analysis of the fMRI serie using movements
parameters as a regressors has been performed. The beta values of that
analysis corresponded to to movement parameter percentual that better
match the intensity variations. By default, mean image intensity of
fMRI series is set to 100 (grand mean scaling), so to correct for
movement you could use the formula:
I100'=I100-beta1*p1-beta2*p2-....-beta6*p6
where p1,..p6 represent the 6 movement parameters and I100 is the
original image scaled to 100
Thank you
Carles Falcon
|