Hi Maayan, You first need to manually concatenate your scans and onsets manually to specify a one-session SPM.mat. Then, to adjust the high-pass filter and add session regressors, you need to run spm_fmri_concatenate. Then you can estimate the model. Best, Peter -----Original Message----- From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]] On Behalf Of Merhav, Maayan /DZNE Sent: 30 September 2015 13:17 To: [log in to unmask] Subject: [SPM] Concatenating Hello, I am trying to concatenate two fmri sessions. I follow the command spm_fmri_concatenate('SPM.mat', scans); (instructions in wiki) but the comment says I have to put just a one-session spm.mat file. Could there be a logical problem in this command? I also tried to follow these instructions https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=spm;f7b2ada7.1507 but it did not help. Does anyone actually used it? Thanks in advance, Maayan