Hello everyone, I have a few questions about extracting trial-averaged
timeseries data using FSL. Basically, I am trying to extract HRFs from
subjects using a checkerboard task.
1) I was just wondering if the timeseries output of Featquery
(mean_mask_ts.txt) takes into account the filtering and prewhitening
that occurs in the feat glm.
2) Should I be using tsplot instead, would it take these issues into
3) How can I use tsplot over a whole roi instead of a single voxel?
Why would I want to weight my extracted timeseries by z-value (as
tsplot does by default)? That seems like it would clean up the
timecourse alot, but unnaturally so and eliminate my ability to compare
HRFs of different subjects.
4) I have been trying to find activity in my task by using a set of 3
sin and 3 cos waves (harmonics, the lowest frequency one being 18s).
If I use all 3 harmonics of the 18s sin, I get the linear combination
error with a ratio on the order of 10^-2. My understanding is that a
ratio at that level is ok, and that I can safely continue. Is there a
better way to do this, perhaps using a gamma basis set ?
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Clinical Neuroscience Lab, UCLA