AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

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kittyzxu
February 08, 2016 12:45PM
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.
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making stimuli timing file for PPI analysis

kittyzxu February 08, 2016 12:45PM