Hello,

I am trying to use FSFAST to map polar angle retinotopy and wanted to make sure I am following the right steps as well as understanding the final visualization. These are the current list of commands I am using, after already making a flattened occipital patch:

preproc-sess -sf sessid -df SUBJ01 -surface self lhrh -fwhm 0 -fsd bold -per-session
mkanalysis-sess -a rtopy.self.lh -surface self lh -TR 2 -retinotopy 24 -paradigm rtopy.par -per-session -fsd bold -fwhm 0 -ngroups 3
selxavg3-sess -a rtopy.self.lh -sf sessid
fieldsign-sess -a rtopy.self.lh -patch lh.occip.patch.flat -sf sessid
rtview --s s101 --hemi lh --polar --real polar/real.nii.gz --imag polar/imag.nii.gz --fsig polar/fsig.nii.gz --flat

1. Am I correct in saying that to do retinotopy with only polar mapping runs, I have to make a fake folder with eccentricity data (otherwise selxavg3 will error)?

2. After rtview, I am using this color wheel after changing the color scheme from "color wheel" to "RYGB colors" in tksurfer. However, I am not even sure this is the right color wheel to be looking at. (If it is, do I need to flip it horizontally when looking at the left hemisphere -- the stripes seem to follow the same color pattern across l and r hemispheres for me?)

3. Is the color wheel represented in radians? If so, how can I figure out what radian a certain color is?

4. I specified -ngroups 3 because I used multiband with a factor of 3, but I also tried running this all without -ngroups specified and everything seemed to come out the same. Is ngroups necessary if we collected slices using multiband or no?

Thanks very much for any assistance,

Paul Scotti