Between group FC

Dear Yan,

Although I am still learning, I am very happy with your software for the resting state analyses.

However, I have a doubt. I performed the FC analyes considering the ROI1. Then, I used SPM to compare two groups G1 and G2. At the whole brain, I obtain a significative difference between the two groups in the cluster C1.

So, I entered again in the analyses either ROI1 and C1 in order to obrain the functional connectivity between these two regions, extracting the values for each subject and to use these values for further analyses (e.g. correlating the ROI-wise FC with any neuropsychological measure).

Question 1- is that procedure correct?

Question 2- when I extracted the values, I performed the indipendent t-test between G1 and G2, but the differense is not statistically significant. However, I would do expect that they represent the same analyses that I run with SPM. Am I wrong? In case, why the two analyses have different outcomes?

 

Thank you in advance

Forums:

1. The procedure should be OK.

2. Usually they should be close, but not identical. As one is averaging the time series first, one is averaging the t values.