open-discussion > SPM12 Contrast Manager Multiple Sessions
Showing 1-1 of 1 posts
Mar 3, 2020 09:03 PM | Angelina Kancheva
SPM12 Contrast Manager Multiple Sessions
Hello everyone,
I'm using SPM12 to analyze fMRI data with the goal to recreate the Penfield map and verify the anatomical locations of feet, left hand, right hand, and tongue on the motor cortex.
I have specified a 1st level analysis model for a single subject where I have 4 different sessions/tasks (movement of feet task, movement of left hand task, movement of right hand taks, and movement of tongue task).
In total, I have 32 factors. For each session, I get a design matrix with a single factor of interest (movement of feet or left hand or right hand or tongue), 6 motion parameters, and the mean signal, so that's 8 factors x 4 for the four sessions.
I'm designing contrasts with the idea to compare the separate conditions against each other. I'm having a bit of a hard time getting my head around all the required contrasts so as to be able to find and compare the localizations of feet, left hand, right hand, and tongue.
So far, I've thought of the following contrasts:
Within contrasts:
Feet movement activation:
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0
Left hand movement activation:
0 0 0 0 0 0 0 0 1 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Right hand movement activation:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Tongue movement activation:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
Between contrasts:
Feet > left, right and tongue:
1.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Left hand > feet, right and tongue:
-0.5 0 0 0 0 0 0 0 1.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Right hand > feet, left and tongue:
-0.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 1.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Tongue > feet, left and right:
-0.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 1.5 0 0 0 0 0 0 0
Do these weights make sense? Would people be able to think of more parsimonious ways to answer the research question?
Many thanks in advance.
Regards,
Angelina
I'm using SPM12 to analyze fMRI data with the goal to recreate the Penfield map and verify the anatomical locations of feet, left hand, right hand, and tongue on the motor cortex.
I have specified a 1st level analysis model for a single subject where I have 4 different sessions/tasks (movement of feet task, movement of left hand task, movement of right hand taks, and movement of tongue task).
In total, I have 32 factors. For each session, I get a design matrix with a single factor of interest (movement of feet or left hand or right hand or tongue), 6 motion parameters, and the mean signal, so that's 8 factors x 4 for the four sessions.
I'm designing contrasts with the idea to compare the separate conditions against each other. I'm having a bit of a hard time getting my head around all the required contrasts so as to be able to find and compare the localizations of feet, left hand, right hand, and tongue.
So far, I've thought of the following contrasts:
Within contrasts:
Feet movement activation:
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0
Left hand movement activation:
0 0 0 0 0 0 0 0 1 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Right hand movement activation:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Tongue movement activation:
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0
Between contrasts:
Feet > left, right and tongue:
1.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Left hand > feet, right and tongue:
-0.5 0 0 0 0 0 0 0 1.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Right hand > feet, left and tongue:
-0.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 1.5 00 0 0 0 0 0 -0.5 0 0 0 0 0 0 0
Tongue > feet, left and right:
-0.5 0 0 0 0 0 0 0 -0.5 0 0 0 0 0 0 0 -0.5 00 0 0 0 0 0 1.5 0 0 0 0 0 0 0
Do these weights make sense? Would people be able to think of more parsimonious ways to answer the research question?
Many thanks in advance.
Regards,
Angelina