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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gang
January 21, 2015 01:24PM
> As I understand it, for each voxel the program computes the correlation across the
> time domain, and then sums across the space domain.

Yes, that's right.

> If this is the case, then the temporal discontinuities would create jumps in the data,
> thus increasing the shared variance.

The correlation between the time series at any two voxels is basically (assuming the time series have been standardized for simplification)

sum(Xi Yi) / (n-1).

In other words, the correlation coefficient roughly measures the overall synchronization between the two voxels, and it does not assume any temporal continuity in the time series.

Gang



Edited 1 time(s). Last edit at 01/21/2015 01:34PM by Gang.
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Subject Author Posted

Inputs for 3dTcorrMap during task-based fMRI

Nicholas Balderston January 20, 2015 01:56PM

Re: Inputs for 3dTcorrMap during task-based fMRI

gang January 20, 2015 03:03PM

Re: Inputs for 3dTcorrMap during task-based fMRI

Nicholas Balderston January 20, 2015 05:49PM

Re: Inputs for 3dTcorrMap during task-based fMRI

gang January 21, 2015 01:24PM

Re: Inputs for 3dTcorrMap during task-based fMRI

Nicholas Balderston January 21, 2015 01:44PM