help
help > RE: NBS Design matrix for EEG connectivity
Nov 30, 2021 01:11 PM | Tyler Durden
RE: NBS Design matrix for EEG connectivity
Hi Andrew,
thank you for the quick reply and your help. Indeed I did not see the help option. I have constructed my data according to your comments: So I have concatenated connectivity matrices (pre & post per participant) for 12 participants and the resulting connectivity matrix has the dimensions 32x32x24. I used the paired t-test as a statistical model. However, when I run NBS with 12 participants, all p-values are 1.0. I then tried to run the NBS with less participants (n=3) and it works there or at least I get more regular p-values. I attached my design matrices for 12 participants because I think there might be a mistake in there...although I built it according to the help function. The contrasts I used were [0,0,0,0,0,0,0,0,0,0,0,0,1] for n=12 and [0,0,0,1] for n=3.
I'm fairly new to this so please excuse these basic questions.
Best,
T.
Originally posted by Andrew Zalesky:
thank you for the quick reply and your help. Indeed I did not see the help option. I have constructed my data according to your comments: So I have concatenated connectivity matrices (pre & post per participant) for 12 participants and the resulting connectivity matrix has the dimensions 32x32x24. I used the paired t-test as a statistical model. However, when I run NBS with 12 participants, all p-values are 1.0. I then tried to run the NBS with less participants (n=3) and it works there or at least I get more regular p-values. I attached my design matrices for 12 participants because I think there might be a mistake in there...although I built it according to the help function. The contrasts I used were [0,0,0,0,0,0,0,0,0,0,0,0,1] for n=12 and [0,0,0,1] for n=3.
I'm fairly new to this so please excuse these basic questions.
Best,
T.
Originally posted by Andrew Zalesky:
Hi Tyler,
take a look at the NBS Manual or click on the Help button. Numerous design matrix examples are provided.
For you experiment, you would perform a repeated measures t-test. It is repeated measures because the two measurements are acquired for each subject (i.e., pre and post).
The concatenated connectivity matrices should be of dimensions 32 x 32 x N, where N is double the number of subjects. Double because each subject has a pre and post connectivity matrix.
I am not sure why the third dimension is 2 in your case.
The number of rows in the design matrix must equal N.
best,
Andrew
Originally posted by Tyler Durden:
take a look at the NBS Manual or click on the Help button. Numerous design matrix examples are provided.
For you experiment, you would perform a repeated measures t-test. It is repeated measures because the two measurements are acquired for each subject (i.e., pre and post).
The concatenated connectivity matrices should be of dimensions 32 x 32 x N, where N is double the number of subjects. Double because each subject has a pre and post connectivity matrix.
I am not sure why the third dimension is 2 in your case.
The number of rows in the design matrix must equal N.
best,
Andrew
Originally posted by Tyler Durden:
Dear all,
I have two connectivity matrices (32 channel EEG) holding average phase lag indices of Condition A (pre) and Condition B (post) and I aim to compare them using the network based statistics toolbox (NBS). The concatenated connectivity matrix has the dimension 32x32x2. I also loaded the node coordinates. However I have trouble understanding the design matrix. What does the matrix need to look like if I want to obtain the statistical differences between both matrices? I tried some example but I always get the error: "Design matrix not found or inconsistent". I hope you can help me!
Best,
T.
I have two connectivity matrices (32 channel EEG) holding average phase lag indices of Condition A (pre) and Condition B (post) and I aim to compare them using the network based statistics toolbox (NBS). The concatenated connectivity matrix has the dimension 32x32x2. I also loaded the node coordinates. However I have trouble understanding the design matrix. What does the matrix need to look like if I want to obtain the statistical differences between both matrices? I tried some example but I always get the error: "Design matrix not found or inconsistent". I hope you can help me!
Best,
T.
Threaded View
| Title | Author | Date |
|---|---|---|
| Tyler Durden | Nov 26, 2021 | |
| Andrew Zalesky | Nov 26, 2021 | |
| Tyler Durden | Nov 30, 2021 | |
| Andrew Zalesky | Dec 1, 2021 | |
| Tyler Durden | Dec 7, 2021 | |