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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Ellen Shlossberg
June 10, 2004 11:54AM
Hello,

I am comparing SPECT data of 100 Alzheimer patients. They have been divided into groups of converted, questionable, and normal patients, with a MannWhitney test run on each group. Now I must find the maximum threshold for comparison for a p value of 0.005. I have tried running AlphaSim simulations a cluster connectivity radius of 1, gaussian filter width 10, 1000 iterations, and a mask of one of the patients.

This however has not given me the desired results. A reliable source has suggested the threshold value will be 2.798 with a maximum cluster size of 692. I will need to remove all data from the functional datasets that is below the necessary cluster size, so I will be running 3dmerge on each of the three MannWhitney tests, but I am still not sure how to acquire the correct threshold value for my tests.

Please let me know if you can help.

Thanks,
Ellen
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voxel probability

Ellen Shlossberg June 10, 2004 11:54AM