Fig. 13.

Investigation of S-var, slow variability artifacts. When $S_t$ and $D_t$ coincide, like at $t=871$ (Panel A), the S-var image shows no particular structure. In contrast, we find multiple S-var excursions correspond to a common pattern of vascular variability across the acquisition, with time points $t=591$, 202 and 1030 shown in panels B, C and D, respectively.