I am currently running a region of interest (ROI) RSA on the concatenated fMRI data and I am facing a weird pattern of activations. The general same structure of activations is present across all ROIs and weirdly enough is present also in cerebro-spinal fluid (CSF) and white matter. I haven’t still tested the differences between the regions and I am sure that there will be differences. However, is it common to have the same general pattern of activations even in the regions which theoretically should not show any specific patterns (the white matter and the CSF in my case)? Did anyone experience the same lack of region specificities?