Dear Alfonso,

In an alternating block design where there is no resting period (ABABABAB...), I am wondering if this design is inherently ill-suited for meaningful PPI analyses.
In your previous response to others, you mentioned that AxROI (or BxROI) itself cannot be meaningfully interpreted, because there is no clear baseline here.
If so, I am wondering if (AxROI - BxROI) can be meaningfully interpreted in such alternating block design without any rest periods.

Many thanks!!
Daniel