Hello,

We have been trying to analyze some longitudinal structural data using the FreeSurfer Mixed Effects Model toolbox and have been running into some issues.

We have 2-3 timepoints per individual imaged across adolescence and 3 groups of interest. We set up a design matrix to examine potential quadratic effects of age by group including factors for:

1. Intercept

2. time

3. time ^2

4. Group 1 vs. others

5. Group 1 x time

6. Group 1 x time ^2

7. Group 2 vs. others

8. Group 2 x time

9. Group 2 x time ^2

10. age at baseline

11. sex

We started a model to examine thickness, testing out the first model below

[lhTh0,lhRe] = lme_mass_fit_EMinit(X,[1 2 3],Y,ni,lhcortex);

Then, we have been getting stuck at

[lhRgs,lhRgMeans] = lme_mass_RgGrow(lhsphere,lhRe,lhTh0,lhcortex,2,95);

This starts the segmentation into homogeneous region but seems to get stuck after displaying "Computing seeds..."

Is there a way to diagnose or fix this problem? Any thoughts would be great, thanks!