Thank you again for the help. One last question following up the goodness of fit -- how good should I be expecting for neuroimaging data? I am now looking at result from one run in which we compared BOLD signal when the (non-stroke) subject was moving his hand versus no movement, which should have very significant signal. However, for the voxel in motor cortex that has the largest z value (18+), the ratio of temporal std of residuals to temporal std of filtered_func_data time series is as high as 0.38. In data from a stroke patient, the ratio was 0.55 for a voxel that has z value of 6. They all seem pretty high to me, is it normal?
Thank you very much,