Time 0 is the time at which the first *stored* image was acquired. So, if you have 10 sec of dummy scans that are not in the stored volume, that 10 sec would not be represented in the par file. How much effect the fine detail of the timing has depends upon the type of experiment. For blocked designs, you're generally spending more time on the plateau of the block, and timing is not as important. For event-related designs, timing is much more important.
doug
Margaret Duff wrote:
Hello, When writing par files for each functional run, do you match the timing of the stimuli to the ideal timing (starting at zero), the ideal adjusted timing for the 10 seconds of dummy scans (starting at 10 s), or the timing from the log files from Presentation? How much does this timing affect the data? Thanks, Margaret
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer