Dear FREESURFERs,

I'm performing retinotopy analysis. I preprocessed data and made 1st level analysis.

Stimuli definition is: 6 cycles of rotating wedge (counter-clockwise rotation) and 6 cycles of expanding ring. One cycle lasts ~41 seconds. Scan TR = 2.5 sec.

I followed the pipeline below (after recon-all):

preproc-sess -sf sessid -fsd bold -fwhm 5 -surface self lhrh -per-run

mkanalysis-sess -a ret_?h -surface self ?h -fwhm 5 -retinotopy 41 -paradigm rtopy.par -TR 2.5 -fsd bold -per-run

selxavg3-sess -a ret_?h -s SUBJ01 (let's say first subject)

I created an occipital flat patch and then:

fieldsign-sess -a ret_?l -patch lh.occip.patch.flat -s SUBJ01

Then, I visualize results using

tksurfer-sess -a ret_?h -s SUBJ01 -map angle -tksurfer
tksurfer-sess -a ret_?h -s SUBJ01 -map angle.masked -tksurfer
tksurfer-sess -a ret_?h -s SUBJ01 -tksurfer

tksurfer-sess -a ret_?h -s SUBJ01 -fieldsign -tksurfer

I'm not sure about the activations I get and I'm not sure how to interpret these data.

What are the colors in the colorbar telling me?

What is fieldsign img showing?

what's the difference between raw angle and angle.masked (is this the mask created during preprocessing?)?

In angle.masked result, the red part is the center of population receptive fields deducted from eccentricity or from polar?

Here the link to the folder with images

Any help on interpreting these results would be much appreciated.

Thank you,

Marco

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Marco Ninghetto, PhD candidate
Laboratory of Neuroplasticity
Nencki Institute of Experimental Biology
Polish Academy of Sciences
3 Pasteur Street, 02-093 Warsaw, Poland