Hi Cesar, for your case, it would correspond to 4sec prior to stimulus onset (the TR that goes from -4 to -3 sec). What seems to be wrong? The last frame would be the TR that goes from +9sec to +10 sec. Not related to your question, but Is 10 sec post stimulus long enough? doug
On 03/05/2013 11:53 AM, Cesar E Echavarria wrote:
Hi Freesurfers,
I did an FIR analysis to get the BOLD response over time, the following way
mkanalysis-sess -analysis Afterimage_FIR2.rh -surface self rh -native -fwhm 5 -paradigm ShapeAE_New.par -event-related -polyfit 1 -mcextreg -TR 1.000 -nconditions 8 -force -fsd bold -fir 4 14
I then generated the relevant contrasts, ran the funcroi-config command, and the func-roi-table-sess command to create 14 files for my ROI, each containing the signal value at 14 different time points.
i.e. funcroi-table-sess -sf sessid -roi Labels/rh.V1 -c condition1 -map cespct -o ROI/frame0 -frame 0
funcroi-table-sess -sf sessid -roi Labels/rh.V1 -c condition1 -map cespct -o ROI/frame1 -frame 1
. . . funcroi-table-sess -sf sessid -roi Labels/rh.V1 -c condition1 -map cespct -o ROI/frame13 -frame 13
My question is this:
To what time point (relative to stimulus onset) does the value in the frame0 file correspond?
As I understand it, the first 4 frame values should correspond to activity pre-stimulus. However, this expectation is not corroborated by the timing and pattern of the BOLD response I am observing.
I would appreciate any guidance on this issue.
Thanks,
Cesar Echavarria