Dear FSL experts,
I have sent you an email last week and I have not received a reply yet, So I would appreciate any advice you could give me regarding my previous post (Please see the email below)
Thank you very much
Lorena
Subject: GLM
From: Lorena Jimenez-Castro <
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Reply-To: FSL - FMRIB's Software Library <
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Date: Mon, 28 Nov 2011 22:37:43 +0000
Reply
Dear FSL experts,
I would like to verify if I am on the right track setting up a design for a resting state seed based analysis on a group of 13 subjects with pre and post treatment data. I am trying to set up the design matrix and design contrast to run the higher-level analysis using FEAT. I know I have to use “one group paired t test†but also I want to use “contrast masking†to mask the positive and negative co-activation, that is why I also need to get from the pre and post groups the correspond negative co-activation mean and positive co-activation mean.
I would like to know if the following designs are correct:
Design matrix:
subject
group
EV1
EV2
EV3
EV4
. . .
EV13 EV14
1
1
1
1
0
0
0
0
2
1
1
0
1
0
0
0
3
1
1
0
0
1
0
0
.
.
13
1
1
0
0
0
0
1
14
1
-1
1
0
0
0
0
15
1
-1
0
1
0
0
0
.
.
26
1
-1
0
0
0
0
1
Design Contrast:
EV1 EV2 EV3 EV12
EV13
EV14
c1: preTx_ positive correlation > post_tx 1
0
0
. . . ..
0
0
0
C2:post_tx positive correlation > pre_tx
-1
0
0
0
0
0
C3:pre_tx positive correlation mean
1
1
1
1
1
1
C4:post_tx positive correlation mean
-1
1
1
1
1
1
C5: pre_tx negative correlation mean
1
-1
-1
-1
-1
-1
C6: post_tx negative correlation mean
-1
-1
-1
-1
-1
-1
C7: preTx_ negative correlation > post_tx -1
0
0
0
0
0
C8: post_tx negative correlation > pre_tx
1
0
0
0
0
0
Contrast masking:
C1 with C3>0 = real preTx_ positive correlation > post_tx
C2 with C4>0 =real post_tx positive correlation > pre_tx
C7 with C5>0 = real preTx_ negative correlation > post_tx
C8 with C6>0= real post_tx negative correlation > pre_tx
Am I doing the right thing?
Any hint on this would be greatly appreciated
Thanks
Lorena
