Fig. 4.

(a) The visual stimulation paradigm consists of 5 interleaved blocks of rest (REST) and stimulation (STIM). Each block takes 4.65 min, resulting in a total duration of 46.8 min. (b) In vivo brain $k_{\text{CK}}$ maps estimated from the averaged REST and STIM blocks, respectively, and (c) the percentage difference change (DIFF) from REST to STIM. Clusters (size ≥ 20) with a change ≥ 10% are displayed. The DIFF map is overlaid on a coregistered $T_1$-weighted ¹H-MR image.