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Hi FreeSurfer Experts,
I had a question regarding contrasts for univariate LME models.
I am interested in looking at the interaction of alcohol with change in volume
across two time-points. Included in my model are covariates Gender, ICV, and
Previ
Yes, it was arbitrary. A linear trajectory was a sufficiently good model for
the mean response over time for most of the cortex points in my analyses. Also
if you only have at most three time points per user then you can only have at
most two random effects in your mixed-model (intercept and tim
Hi Jordi
You have implicitlyincluded the reference group in your statistical model by
includingan intercept term and a time variable:
group0 intercept: ß1group0 time: ß2group1 intercept:ß1+ß3group1 time:
ß2+ß4group2 intercept:ß1+ß5group2 time: ß2+ß6
>From here you canquickly see that your prop
Dear FreeSurfer experts,
I would appreciate a confirmation regarding correctness of my approach.
I am trying to run an LME model for three groups (group1=controls, group2 and
group3) and two time points.
I followed the tutorial on
https://surfer.nmr.mgh.harvard.edu/fswiki/LinearMixedEffectsM
viado:* Martes 12 de febrero de 2013 18:29
*Asunto:* [Freesurfer] LME - contrast
Dear Jorge,
For the statistical analysis of longitudinal data we used the "Two
Stage Model" (TSM) and the "Linear Mixed Effects".
Our intergroup LME results (2 groups
Best
-Jorge
>
> De: Alex Hanganu
>Para: FS Mailing List ; Jorge L. Bernal-Rusiel
>
>Enviado: Martes 12 de febrero de 2013 18:29
>Asunto: [Freesurfer] LME - contrast
>
>
>Dear Jorge,
>
>For the statistical analysis of longitudinal
Dear Jorge,
For the statistical analysis of longitudinal data we used the "Two Stage
Model" (TSM) and the "Linear Mixed Effects".
Our intergroup LME results (2 groups, 2 time points) had many
similarities with TSM results. Then with TSM we analysed the intragroup
changes (one group, and 2 ti
