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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Isaac Schwabacher
November 25, 2014 04:43PM
The figure in that paper incorrectly suggests that the method used was an average of the correlations, which can be accomplished in the way you suggest, but buried in the text is a description that matches 3dTcorrMap -Zmean, which doesn't reduce to the easier case:

Quote

Weighted global brain connectivity (wGBC) analysis

See the middle left portion of Fig. 2 for an outline of wGBC analysis. We developed the wGBC analysis method initially using MATLAB (The MathWorks, Natick, MA), switching to a more efficient function (AFNI's 3dTcorrMap) for the findings reported here. wGBC analysis involves seed-based correlation of each gray matter voxel with all other gray matter voxels. These values are then averaged together and the resulting value (i.e., that voxel's wGBC) is assigned to that voxel in a new brain map. Fisher's z transformation is applied to each (Pearson's r) correlation prior to averaging, and then converted back to r-values afterward. This process repeats for all gray matter voxels, resulting in a single brain map per subject reflecting wGBC.
(emphasis mine)
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Subject Author Posted

Identifying the brain's most globally connected regions

afniuser November 25, 2014 09:13AM

Re: Identifying the brain's most globally connected regions

rick reynolds November 25, 2014 04:30PM

Re: Identifying the brain's most globally connected regions

Isaac Schwabacher November 25, 2014 04:43PM

Re: Identifying the brain's most globally connected regions

afniuser November 26, 2014 05:30AM