Hi FSL experts,
Currently I am working a resting-state dataset download from http://www.birncommunity.org/resources/data/.
This dataset contains 16 subjects (4 runs for each subject). I did three seed-based resting state analysis with this dataset. The three seeds were left A1, right A1, and V1. I constructed two contrasts: positive correlation with the ROI activity, and negative correlation with the ROI activity. The analysis results seem weird, for the positive correlation contrast, most of the participants showed (almost) whole brain activation; and for the negative correlation contrast, there is no activation in any of the participants. Are these results normal? What the problems may be?
Following are my analysis steps:
(1) Brain extracted the BOLD and structural images, and motion correlated the BOLD
(2) Define ROI using anatomical atlas: Juelich-maxpro-thr25-2mm.nii.gz
(3) Register ROI to individual BOLD using standard2ample.mat, so that we could get the ROI mask,
(4) Using the ROI mask, to get the mean activity values of the ROI in individual participants.
(5) Run first level analysis for each run. In the model, we set up 7 EVs: one EV of the ROI activity, the other six were motpars. We set up two contrasts [1, -1] with the ROI EV.
(6) Run second level analysis for the four runs in each participants
(7) Run group analysis for all the participants.
Thanks in advance!
Best,
Zilong
|