Dear Afni group,

I have a simple question but I am confused by the various options available in Afni. I am trying to decide with which AFNI function to analyse my simple 2 (context A vs context B) x 2 (stimulus A vs. stimulus B) repeated measures within-subject design (in a sample of adolescents). I know that 3dttest++ and 3dLME give me the different contrasts (or maybe I misunderstood the example provided on the 3dLME page) but I am wondering about explicitly modelling the interaction term but wasn't sure how to go about it.

In addition, I actually happen to have analysed that dataset previously with GroupAna and a second group (adults). One question is, in the GroupAna design file I had created the individual contrasts for each level of my within subjects factor for each group separately (for example -adolescents: context A with stimulus A AND adolescents: context A with stimulus B). Thus, would I be allowed to use the contrasts computed from this analysis in GroupAna or should I compute new ones? I am not sure whether statistically these are independent and would or would not change regardless of whether at the higher up level there exists a second group

Thus 1) which Afni program do you recommend to explicitly model the interaction in a repeated measures within subject design in a 2 x 2 Anova?
and
2) can I re-use the individual group contrasts calculated from a GroupAna?

Thanks in advance for your help,

Sven