Dear Ziad,
Thanks kindly for your response.
To confirm, using tent will ultimately give me the HRF beginning at the time specified in stim_times. So, if I want to treat the times in stim_times as the beginning of 4 sec blocks and extract the HRF from the end of these blocks, I need to either add 4 to the times in the stim_times files, or ignore the first 2 TR (TR=2sec) in the HRF time series output and make it longer to capture the duration I want.
Does that sound right?
Also, do you know if there is a way to combine conditions via -iresp?
Thanks,
Marc