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 Chen
October 10, 2007 04:14PM
> We are concerned that voxels with activation in one dataset may be
> dropped if they happen to be compared to zero value voxels in the
> second dataset.

Do you mean whether it is possible a voxel labeled "activated" for some subjects during individual analysis might end up showing no difference when compared to zero at group level? If so, yes it is possible. The reason is that the significance of a condition at individual level is evaluated by the condition effect relative to the noise level for that subject while the difference at group level is judged relative to the inter-subject variability.

AFNI Gang
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Subject Author Posted

t-tests

Mona October 10, 2007 02:51PM

Re: t-tests

Gang Chen October 10, 2007 03:36PM

Re: t-tests

Mona October 10, 2007 03:52PM

Re: t-tests

Gang Chen October 10, 2007 04:14PM