Dear all
our scanner does not have pulse trigger and we have to make the synchronization by 2 person ( one person looking at monitor who was told to say the start of the 5th acquisition , and one starting the stimulus representation at that time !! ) , so here is my question:
is there anybody who had the same experience?
one approach that i think is going to work is that , for example for visual stimuli we know that V1 is activated during the task. if i extract the time series of one voxel in V1 and calculate the correlation between that voxel time series and my stimulus convolved with hrf and then make shift to my presentation time series ( for the possible lag between synchronizations ) and then calculate again. the goal is to find the highest correlation between them.
another thing that comes to mind is that to use different timing for stimulus in FEAT and look at the results which is very time consuming.
