Hi Afni experts,
I am trying to do PPI analysis and am stuck at step 4 (see below)
4. Obtain the interaction regressor
First create a 1D (one column) file, conditionA.1D, with 0's (at those TR's where condition A does not occur), 1's (at those TR's where condition A occurs).
My condition files are two separate .txt. files.
sub_conditionA1: 78 102 109 115 274 315.5 395.5 428
sub_conditionA2: 10.5 34 167.5 192 214 224.5 323 382
(Time is in seconds, and it is the time of a stimulus onset.)
How can I combine these two .txt files, sort them according to the time and convert them into the format that PPI-step 4 describes?
In addition, my TR is 2s, so I will probably upsample and downsample the stimuli timing using a parameter of 4 TR/sub_TR = 2/0.5 = 4. Is this correct?
Thank you!
Kitty
Edited 2 time(s). Last edit at 02/08/2016 12:57PM by kittyzxu.