Hi,
> Hi, I am having problems with setting up high pass filter in 1st level feat.
>
> (1) The value of high pass filter will change depending on how many times I press the estimation button, weird…
Don't worry about this, as long as the values don't change by very much.
> (2) Is it always accurate if I just use the value from "cutoffcalc -i design.mat" ?
No, you also need to set the TR value (e.g. adding the option --tr=2.5 for a TR of 2.5 seconds).
> (3) Can I calculate the high pass filter manually?
There isn't a single correct answer, although you can estimate it.
The best way to make sure that your estimate is OK is to check whether making the cutoff substantially longer gives you a design matrix where the EVs look the same (or very similar, except for maybe some changes right at the ends) when comparing your cutoff with the longer one (set both up in FEAT and compare the View Design windows side by side).
> I got 7 types of blocks (1-7) with resting block in between (r)and a random order, so the order is:
> r 7 r 1 r 2 r 3 r 4 r 5 r 6 r 1 r 5 r 6 r 4 r 7 r 3 r 2 r 2 r 4 r 7 r 3 r 2 r 2 r 4 r 5 r 7 r 1 r 6 r 3
> So I guess the high pass filter is the length of all these (r 7 r 1 r 2 r 3 r 4 r 5 r 6 r 1 r 5 r 6 r 4 r 7 r 3 r 2 r 2 r 4 r 7 r 3 r 2 r 2 r 4 r 5 r 7 r 1 r 6 r 3) ??
There isn't enough information in here to know, since we would need to know the timing information.
However, just check the answer from the GUI estimation, or from the command line cutoffcalc tool, with the above test.
All the best,
Mark
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