Sagittal section of a rat brain illustrating regions implicated in occasion setting and their relevant circuitry is indicated by the directional arrows. Green shading indicates regions for which evidence implicates activity within this region as being critical for the acquisition or expression of occasion setting. Other regions shaded in blue are implicated in simple Pavlovian conditioning but a role for these regions in occasion setting remains to be demonstrated. Evidence for the involvement of the dHIPP, shaded in red, in occasion setting is mixed and requires further study. BLA basolateral amygdala, dHIPP dorsal hippocampus, mPFC medial prefrontal cortex, NAc nucleus accumbens, OFC orbitofrontal cortex, PVT paraventricular nucleus of the thalamus, vHIPP ventral hippocampus, VTA ventral tegmental area.