stim_times_IM and TENT

AFNI Message Board
1

Hi
Using stim_times_IM and TENT(0,8,5) in the 3dDeconvolve, I got output with 432 sub-bricks. My question is the neighbor brick means neighbor stimulus (in stim_times_IM) or neighbor TRs (in TENT)?
Thanks
rujing zha

2

You didn’t provide a detailed description about your experiment design and the modeling details. Also, without access to those sub-brick labels, it’s hard to answer your question. Nevertheless, the labels you specified in the script should help you identify what those sub-bricks are associated with.

Also, when using TENT(0,8,5), you assume that there is BOLD response right at the stimulus onset. Make sure this is what you intended. Otherwise, it may be better to use TENTzero.

3

Hi rujing zha,

The TENTs are kept together, the neighboring bricks go across TENTs. Each set of TENTs will be grouped before those for the next event in IM.

Note that in such a design, it would be bad for the BOLD responses for any events to overlap. This is a dangerous design in any case, since these TENTs might fit single time points (and therefore perfectly), if they are TR-locked events.

  • rick