Hi FSL experts,
My Feat analysis showed that a cluster within the left thalamus (local maximum MNI coordinate was x/y/z) is activated during task I. I want to know if the functional connectivity from left thalamus to other brain regions is increased during task I as compared with task II. In other words, I want to perform a PPI analysis in FSL. I have the following 4 ways to extract the physiological parameter of the seed region (i.e., the left thalamus):
A: extract the time series of the activated thalamus cluster
B: extract the time series of the areas within 6-mm radius centred at x/y/z
C: manually define the left thalamus individually in each subject's high-resolution T1 weighted images. Then extract the time series of this thalamic mask
D: extract the time series of the left thalamus defined using the left thalamus mask defined in the Harvard-Oxford atlas
E: There is a meta-analysis using the same tasks and a common activation coordinate of the left thalamus is given. Use this coordinate to repeat procedure in B
I remember that the definition of ROI should be independent, so I guess C,D and E are ok but A and B are not appropriate. hope someone can clarify this for me. Thanks a lot.
Mike
|