AFNI Message Board

History of AFNI updates  

|
June 07, 2022 09:37AM
Hi Misho,

It seems likely that something is not correct with the timing of the task, such as accounting for pre-steady state volumes.

Do the time series initially contain pre-SS volumes?
Do the stim times start at the beginning of pre-SS, or after?
Did you make any adjustments to the stimulus timing to account for pre-SS?
If you need to tell 3dTshift that the TR is 2s, maybe it is not correct in the headers, in which case 3dDeconvolve will not know either.
What does 3dinfo -tr show for those time series?

Smaller points:
I see you are telling afni_proc.py to remove the first 2 time points, which is only 4s of data. Typically it 7-10 s.
With TR=2s, such bandpassing will consume 60% of the degrees of freedom. It is generally not recommended, particularly in the case of task.
That might end up devouring some of the variance of those long, slow blocks, too.

- rick
Subject Author Posted

Speckles in vstat - Hariri faces task Attachments

misho_dimitrov June 07, 2022 03:20AM

Re: Speckles in vstat - Hariri faces task

rick reynolds June 07, 2022 09:37AM

Re: Speckles in vstat - Hariri faces task

misho_dimitrov June 08, 2022 03:26AM

Re: Speckles in vstat - Hariri faces task

misho_dimitrov June 08, 2022 05:51AM

Re: Speckles in vstat - Hariri faces task

rick reynolds June 08, 2022 02:31PM

Re: Speckles in vstat - Hariri faces task

ptaylor June 08, 2022 03:11PM

Re: Speckles in vstat - Hariri faces task

misho_dimitrov June 13, 2022 10:11AM



Sorry, only registered users may post in this forum.

Click here to login