Thanks Gang for your answers!
I have two other concerns:
A) Since the average of the two effects for SPMG1 (with and without parametric modulation) is not meaningful/interpretable, I wanted to obtain the individual contrast for:
1. the intercept, by doing this:
-gltsym 'SYM: S[0] -I[0]' \
2. and the slope, by doint this:
-gltsym 'SYM: S[1] -I[1]' \
However, when I process the data I get an error message related with the selector for the index 1, like this one:
------------------------------------------------------------
GLT matrix from 'SYM: S':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0
------------------------------------------------------------
GLT matrix from 'SYM: S -I':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 1 1 0 0 0 0 0 0
------------------------------------------------------------
GLT matrix from 'SYM: S[0] -I[0]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 1 0 0 0 0 0 0 0
** ERROR: selector index 1 is out of range 0..0
------------------------------------------------------------
GLT matrix from 'SYM: S[1] -I[1]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 1 0 0 0 0 0 0
------------------------------------------------------------
Similar error is showed for other contrasts (e.g. S[1] -B[1]).
The analysis is done, in a sense that I still get this contrast as a sub-brik in the stats-bucket generated when the regression is done. Still, being an error message, and based on one of your advice from some tutorial related with the error messages versus warning messages, I am wondering whether I should/shouldn't worry about this error message printed out in the terminal, and eventually what it means?
B) As for the SPMG1, when I do the analysis for SPMG2, since the average of the four effects for SPMG2 (two with and other two without parametric modulation) is not meaningful/interpretable, I wanted to obtain the individual contrast for:
1. the intercept of the major component of the hemodynamic response, by doing this:
-gltsym 'SYM: S[0] -I[0]' \
2. the intercept of the first-order derivative, by doing this:
-gltsym 'SYM: S[1] -I[1]' \
3. the slope (modulation) of the major component of the hemodynamic response, by doing this:
-gltsym 'SYM: S[2] -I[2]' \
4. and the slope (modulation) of the first-order derivative, by doint this:
-gltsym 'SYM: S[3] -I[3]' \
However, when I process the data I get similar error message, related with the selector for the index 1 (again only when the modulation effect is considered, this time for both components of SPMG2), like this one:
------------------------------------------------------------
GLT matrix from 'SYM: S':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0
------------------------------------------------------------
GLT matrix from 'SYM: S -I':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 -1 1 1 1 1 0 0 0 0 0 0
------------------------------------------------------------
GLT matrix from 'SYM: S[0] -I[0]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 1 0 0 0 0 0 0 0 0 0
------------------------------------------------------------
GLT matrix from 'SYM: S[1] -I[1]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 1 0 0 0 0 0 0 0 0
** ERROR: selector index 2 is out of range 0..1
------------------------------------------------------------
GLT matrix from 'SYM: S[2] -I[2]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 -1 0 0 1 0 0 0 0 0 0 0
** ERROR: selector index 3 is out of range 0..1
------------------------------------------------------------
GLT matrix from 'SYM: S[3] -I[3]':
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 -1 0 0 0 1 0 0 0 0 0 0
------------------------------------------------------------
Like for SPMG1, for SPMG2 similar error is showed for other contrasts (e.g. S[1] -B[1]).
As above, the analysis is done, in a sense that I still get all those contrasts as sub-briks in the stats-bucket generated when the regression is done. Still, being an error message, and based on one of your advice from some tutorial related with the error messages versus warning messages, I am wondering whether I should/shouldn't worry about this error message printed out in the terminal, and eventually what it means?
Thanks in advance for your help!
Ruben.
