How to define "site" as covariate in CONN

Dear all,

I am working with rs-fMRI data collected from four different sites, where the scanning parameters are identical across three of the sites. I want to control for site effects during the 2nd-level analysis by including site as a 2nd-level covariate in CONN toolbox.

To do this, I was planning to create separate 0/1 dummy variables for each site. For example:

  • Site1: [1 1 0 0 0 0 0 0]
  • Site2: [0 0 1 1 0 0 0 0]
  • Site3: [0 0 0 0 1 1 0 0]
  • Site4: [0 0 0 0 0 0 1 1]

Is this the correct approach for setting up site covariates in CONN? If not, could you suggest a better way to control for site effects in 2nd-level analysis?

Thank you for your advice!

Best regards,
Huiying Deng