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Joonkoo > I want to take the "raw signal" and then apply detrending (e.g. highpass > filtering at 128Hz) and temporal autocorrelation correction (e.g. using > AR(1) model) just as how ordinary SPM procedure does. I searched for a > script or a thread concerning this issue, but unfortunately I wasn't able to > find a good advice on this. > So I came up with one idea which is to use the conventional SPM model > estimation procedure *without* any regressor specified. This way, the model > matrix will only include the grand mean (column of ones) for each run. The > residuals from this estimation should, in theory, give me the "highpass > filtered" and "temporal autocorrelation corrected" which is further mean > centered for each run. > sounds good to me - change in spm_defaults the residual number to 'inf' and in spm_spm comment the bit which actually delete the residuals from the disk - also in the design matrix you can enter the txt file from the realignment ; residuals here = data with variance related to motion removed + filtered as you wanted :-) (note the filtering is high pass / AR ~ = low pass / drift) -- also the mean will have been removed (that the contant term in the design matrix) Cyril -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.