Hi Doug,
Thank you for your note and my apologies for a delayed response. To create the sig.mgh file we used a volume specific mri_glmfit analysis, omitting the --surf flag and using our volume specific input (ces.nii.gz in SIRP_LoadRegression_Stable5.3_012616_sm5_mni305). I don't know if this information is helpful but when we've run a nearly identical analysis using almost all of the same participants and a different blood folate marker (serum folate) the volumes came out completely fine. I've tried de-meaning the RBC folate values and re-running the mri_glmfit, but the odd activation persists.
This is our mri_glmfit command: mri_glmfit --y /cluster/roffman/users/Stable5_PerRun/Analyses_GDD/GDD_Adults/137_GDD_RBC_Folate_Cond2vfix_KD/SIRP_LoadRegression_Stable5.3_012616_sm5_mni305/Cond2vFix/ces.nii.gz --fsgd /cluster/roffman/users/fsgd/GDD/137_GDD_Cond2vFix_Covary_RBC_Folate_linear_KDcorrect.fsgd --C /cluster/roffman/users/fsgd/TwoGroups1CovariateRegressOut1Covariate_KD --glmdir /cluster/roffman/users/Stable5_PerRun/Analyses_GDD/GDD_Adults/137_GDD_RBC_Folate_Cond2vfix_KD/SIRP_LoadRegression_Stable5.3_012616_sm5_mni305/Cond2vFix/2vFix_ClassUsed_Covary_RBCFOLATE_Nuis_Age_Gender --fwhm 6 --no-prune
Thank you very much, I am most appreciative of your help!
Kind regards, Kevin
Kevin F. Dowling Clinical Research Coordinator Brain Genomics Laboratory Division of Psychiatric Neuroimaging Martinos Center for Biomedical Imaging Massachusetts General Hospital 149 13th Street Charlestown, MA, 02129 (p) 617.643.2479