 |
 |
Hello all, I ran a t-test statistical analysis on some fMRI data and I need the ResMS image files as part of my study. When reading spm_spm.m file to find out how the mean squared error (ResMS) is calculated, there is mention of a scale factor in 2 places. One of the comments says the ResMS values written to the ResMS.hdr files are scaled by the effective degrees of freedom. At another comment further down, it mentions that the scale factor , 1/effective-degrees-of-freedom, is written into the [struct].pinfo(1) variable. My question is are the values contained in the output ResMS.img files scaled and by what value? I want to retrieve just the raw residual sum of squares values and I imagine they are in the ResMS files either multiplied by a scale factor or not. Note: By raw residual sum of squares I mean ResSS = (Y(actual image values) - Y(estimated image values)) or i.e. the sum(residuals^2)) Thank you. Sincerely, Todd Penney