Don't throw out your data though! If you model separate between- and within-subject effects, you'd see that they're different! Brain-behavior associations across individuals are different than changes within individuals. You can model those separately in your own data without any fancy stats!

Tidbit that you can implement in your own analyses: If you collect longitudinal data you improve efficiency by throwing out half your data! WTF?! If you use baseline ("1st") versus a common longitudinal analysis ("All") effect size decreases! Read on! @kaidikang.bsky.social @meharpist.bsky.social

Thank you, Peg!

Thank you, Arielle!

Improving the replicability of BWAS is undoubtedly a complex challenge w/ no one-size-fits-all solution. Nonetheless, we hope our work offers overarching guidance to enhance the reliability of small-scale BWAS studies, considering their sample size constraints and specific research objectives! 🤗