Dear Michiru,
> I am wondering how to choose a cut-off cycle for a high-pass filter in
> our experiment. It was an fMRI experiment with three conditions
> presented pseudo-randomly, for example a b c b c a c a b. In case of TR
> was x seconds and each epoch 's duration is y seconds, how much the
> appropriate HPF should be?
The period of the highest frequency component of the confounds should,
in general, be twice the maximum (over trials) of the minimum interval
between two instances of any particular trial. In your case the
biggest minimum interval is 2 epochs giving 2*2*y*x seconds of the
cutoff period.
I hope this helps - Karl
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