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May 17, 2021 07:34AM
> Do you know why it produces a result even without the interaction effect being in the model? Would you expect the result to be different?

3dLMEr would not parse the specification properly even though it didn't throw an error in this case. To make sure you get the intended results, rerun the script with corrected coding.

> 1. Is there an association between imaging and Outcome1?
> 2. If yes, does this association get stronger or weaker over time?
> 3. If it changes, is the magnitude of change different between the groups?

In your model specification "Time*Group+Age+Gender+outcome1+outcome2+outcome3+(Time|Subj)", no interaction is assumed between Time and outcome1. Thus, to answer the three questions above, you don't need to get Time involved. For example, for the question "does this association get stronger or weaker over time?", the answer is that the association does not change because you already assumed so in your model.

If you really want to address these three questions, account for the interaction between Time and outcome1 by creating a regressor of their product after proper centering.

Gang
Subject Author Posted

Contrasts for longitudinal 3dLMEr

AFNIuser007 April 30, 2021 10:11AM

Re: Contrasts for longitudinal 3dLMEr

Gang May 01, 2021 08:44AM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 01, 2021 11:53AM

Re: Contrasts for longitudinal 3dLMEr

Gang May 01, 2021 04:37PM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 01, 2021 09:00PM

Re: Contrasts for longitudinal 3dLMEr

Gang May 02, 2021 09:00AM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 02, 2021 10:30AM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 13, 2021 12:31PM

Re: Contrasts for longitudinal 3dLMEr

Gang May 13, 2021 10:12PM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 16, 2021 07:07AM

Re: Contrasts for longitudinal 3dLMEr

Gang May 17, 2021 07:34AM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 25, 2021 03:37PM

Re: Contrasts for longitudinal 3dLMEr

Gang May 26, 2021 01:06PM

Re: Contrasts for longitudinal 3dLMEr

AFNIuser007 May 27, 2021 04:11PM



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