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

History of AFNI updates  

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July 01, 2021 11:33AM
If I understand it correctly, what you have done is to perform the seed-based correlation analysis for pre-injection runs and post-injection runs separately. There might have better solutions to compare the voxel-wise correlation values between pre- and post-injection for each monkey, but here is one possibility I cannot think of:

1) Standardize the seed time series for pre- and post-injection runs separately: remove the mean, and divide by the standard deviation

2) Create two separate regressors by appending to the end of the seed time series of the pre-injection runs with the same number of 0s as the number of time points in the post-injection runs, and by adding the same number of 0s as the number of time points in the pre-injection runs to the beginning of the seed time series of the post-injection runs

3) Standardize the EPI time series
-- Remove the mean from each run separately: 3dTstat -mean
-- Detrend each run separately: 3dDetrend
-- Compute the standard deviation for pre- and post-injection runs: 3dTstat -stdev
-- Standardize the data: 3dcalc

4) Compare the correlations between pre- and post-injection runs
-- Create a 3dDeconvolve script with -polort 0 and with standardized data from pre- and post-injection runs concatenated as input
-- Use the two standardized seed time series as two regressors
-- The two regression coefficients would be roughly the seed-based correlations
-- Specify the contrast of the two correlations with -gltsym

Gang



Edited 1 time(s). Last edit at 07/02/2021 04:33AM by Gang.
Subject Author Posted

Comparing Activations Between Conditions Within Scan

niupright14 June 29, 2021 04:50PM

Re: Comparing Activations Between Conditions Within Scan

gang June 30, 2021 09:34AM

Re: Comparing Activations Between Conditions Within Scan

niupright14 June 30, 2021 12:33PM

Re: Comparing Activations Between Conditions Within Scan

gang July 01, 2021 11:33AM