[Icatb-discuss] Spotty masks and "Group ICA Error Information: Error using eig, Input to EIG must not contain NaN or Inf"

[Laura T. <lau...@ph...>]

Dear GIFT experts,

I am trying to do a BOLD resting state analysis with two different 
groups (conditions). I set the parameters to variance normalization, no 
scaling and select a mask (intersection anatomical mask of all 
subjects). If I leave the "remove constant voxels" option as default, I 
get the following error message:

    Group ICA Error Information:

    Error using eig
    Input to EIG must not contain NaN or Inf.

    Error in ==> icatb_eig_symm at 65
    Error in ==> icatb_calculate_pca at 55
    Error in ==> icatb_dataReduction at 797
    Error in ==> icatb_runAnalysis at 366
    Error in ==> runAnalysis_Callback at 95
    Error in ==> gui_mainfcn at 96
    Error in ==> gift at 30

However, if I change the "remove constant voxels" option so that it 
removes the constant voxels, the preselected mask is "updated" and turns 
spotty with holes all throughout the brain. How can I determine what the 
problem is here (I guess these constant voxels are removed throughout 
all subjects and this is why the mask does not contain these areas 
anymore), and exactly where these constant voxels are (so that I can 
figure out whether there are artefacts in the data).

Thank you so much for your help,
best,
Laura

-- 

Dipl.-Biol. Laura Tüshaus
Institut für Pharmakologie und Toxikologie
Winterthurerstrasse 190
8057 Zürich
www.pharma.uzh.ch
Tel.: +41 (0) 44 6355961