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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James Waltz
June 17, 2015 01:28PM
Hi-

I had questions about the instructions for this, as documented here:

[afni.nimh.nih.gov]

My understanding is that the PPI model has to be a full model. But does that mean every psychological regressor needs an interaction term?

In modeling data from a probabilistic reversal learning task, for example, I have four events of interest:
1. Valid rewards leading to stays;
2. Valid punishments leading to stays;
3. Valid punishments leading to shifts;
4. Invalid punishments.

There are several other event-types of less interest:
1. Valid rewards leading to shifts;
2. Invalid rewards;
3. Non-responses
4. Outcomes followed by non-responses.

What is the full model then?

Is it a model with interaction terms between the seed region time series and regressors for the events of interest? All events? Just one or two events?

I am think in terms of the template script I saw on the web page above.

Thanks,

Jim Waltz
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Generalized PPI

James Waltz June 17, 2015 01:28PM

Re: Generalized PPI

gang June 20, 2015 08:45AM