Dear freesurfers,

I try to run a retinotopy analysis following the instruction on

https://surfer.nmr.mgh.harvard.edu/fswiki/FsFastIndividualRetinotopyAnalysis

(using Ubuntu 14.4 and freesurfer 5.3)

My subject folder contains 4 runs (all 'positive polar'). After preprocessing I performed the following steps:

mkanalysis-sess -a retinotopy_polar_pos_rh -TR 2 -paradigm polar_pos.par -retinotopy 30 -surface self rh -per-run -fsd bold -fwhm 5 -nskip 4

selxavg3-sess -s EP_polar -a retinotopy_polar_pos_rh

The polar_pos.par file contains only the two following lines:

stimtype polar

direction pos

selxavg3-sess stops with the following error:

...

Saving X matrix to ~/PROJECTS/Retinotopy/subjects/EP_polar/bold/retinotopy_polar_pos_rh/Xtmp.mat

Error using svd

Input to SVD must not contain NaN or Inf.

Error in cond (line 35)

    s = svd(A);

Error in fast_selxavg3 (line 279)

  XCond = cond(XtX);

>> ------------------------------------------

ERROR: fast_selxavg3() failed\n

I found a lot of similar error reports in the mailing list, but unfortunately no explanation that fix my problem.

Is it maybe a problem when I only process 'polar positve' measurements?  

I also attached the Xtmp.mat file that contains a lot of NaN.

Does someone has an idea what’s going wrong here?

Thanks in advance!

Iris