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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September 12, 2003 10:26AM
An additional point to consider is: what would be the result of
scaling by the maximum value output by waver?

If the stimulus presentation is the same for every run, and the
same for every subject, then max. waver value will be constant.

But consider a random stimulus experiment. In such a case, the
maximum waver output will be dependent upon the timing of the
stimuli. If in one random case, a few similar stimuli are more
or less consecutive, then that could result in a significantly
higher maximum value. Even take a max of 1.5 compared to a max
of 1.2. That's a 25% difference in magnitude, and is possible
under such conditions.

Now consider comparing results from one run to another, and then
from one subject to another. If subject A's response to stimulus
X is 25% higher than that from subject B, what does it mean? It
could simply be the result of some difference in scaling.

Basically, if the scaling facter were to depend on the stimulus
timing (and therefore vary per run and/or subject), it seems like
it could be very difficult to compare resulting beta coefficients.

- rick

Subject Author Posted

waver -peak

Elizabeth Felix September 10, 2003 02:48PM

Re: waver -peak

rick reynolds September 10, 2003 04:34PM

Re: waver -peak

Elizabeth Felix September 10, 2003 04:56PM

Re: waver -peak

Gang Chen September 11, 2003 08:35AM

Re: waver -peak

Elizabeth Felix September 11, 2003 10:13AM

Re: waver -peak

Gang Chen September 11, 2003 10:31AM

Re: waver -peak

rick reynolds September 11, 2003 11:31AM

Re: waver -peak

Elizabeth Felix September 11, 2003 02:32PM

Re: waver -peak

Gang Chen September 11, 2003 04:33PM

Re: waver -peak

Elizabeth Felix September 11, 2003 07:24PM

Re: waver -peak

Gang Chen September 12, 2003 09:37AM

Re: waver -peak

rick reynolds September 12, 2003 10:26AM

Re: waver -peak

Elizabeth Felix September 12, 2003 10:36AM

Re: waver -peak

rick reynolds September 19, 2003 04:22PM