Figure 5.

BOLD activity in dorsal raphe nucleus is correlated with inter-trial interval

(A) To demonstrate that within the midbrain and brainstem the effect of ITI on BOLD is limited to DRN and could not be detected at dopaminergic structures, which may encode other aspects of reward rate, we performed a small-volume correction. The DRN cluster emerged as the only significant cluster (number of voxels = 109; p = 0.04).

(B) We also searched for voxels across the whole brain that showed a significant positive correlation between BOLD and ITI (Z > 3.1) even without performing any cluster correction procedure. Clusters were apparent in hippocampus and caudal DRN.

(C) We replicated the effect of the “broader, general environment” (Figure 3B), which was identified in a priori-defined anatomical DRN mask (Figure 3A), within the functionally defined DRN cluster identified with ITI contrast (A).

See also Figure S6.