Comparing conditions in AM on the group level - to demean or not?

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1

Hello,

I am running amplitude modulation analyses with one AM (let’s call it response). If I want to compare the modulation of response to condition 1 vs condition 2 on the group level (a contrast of condition1[1] - condition2[1] ) do I need to adjust the way the AM events on the individual level are being de-meaned? Specifically, since currently each AM event is being demeaned within each condition, for each person individually, do I instead want to manually calculate the overall mean across subjects and runs within each condition, and manually apply that as the mean in my individual analyses instead? If this is suggested, I haven’t really seen it in any tutorials or any documentation so I’m wondering if it’s not common practice?

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If I want to compare the modulation of response to condition 1 vs condition 2 on the group level (a contrast of
condition1[1] - condition2[1] ) do I need to adjust the way the AM events on the individual level are being de-meaned?

As “condition1[1] - condition2[1]” is the slope effect, it would have no impact as to whether to demean the modulation variable or how to de-mean it.

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Thank you so much, Gang!