Hi Christian,
I've analyzed several data sets and the time course of each of my components starts
at -4 sec. Also, the FFT gives me some negative freqs i.e. x-range = [ -.07576, 1.14].
My TR = 4s and I acquired 36 volumes. I dropped the first 3 volumes. That leaves 4*
33=132s. The range of the time course for each component is [ -4, 124], i.e. a total of
128s.
1. Do you have any idea why the time course starts at -4s and the FFT gives
negative freqs?
2. Do you know what might have happened to the missing volume?
thanks,
jack
--
Jack Grinband, PhD
Mind & Brain Institute
Columbia University
518 PI Annex W. 168th St.
NY, NY 10032
212-543-6931 ext 306
[log in to unmask]
|