Hi AFINI experts!
I am a little bit puzzeled why I get negative values at the edges of the skull after using 3dFourier. I do not see negative values in my unfiltered epi.
I am using the following command:
3dFourier -prefix filt \
-highpass .001136364 \
-lowpass .333333333 \
-retrend \
'origepi+orig'
Retrending has been used because the data are filtered before deconvolution and the data will be detrended (linear trend) anyway, if I correctly understood 3dDeconvolve.
However, I am a little bit bothered by these negative values and I am not quite sure, if they would harm anything further on.
Any suggestions would be appreciated,
Lukas
