Neural Mechanisms of Foraging

Looking for Greener Pastures Humans, like other animals, have evolved to forage. Brain-imaging studies by Kolling et al. (p. 95 ) suggest that activity in the dorsal anterior cingulate cortex supplies a continuous signal of environmental richness predicted by foraging theory. The signal exhibits a frame of reference that is tied to the key foraging decision of whether to engage with the current choice or to search for alternatives. The same strategy is used when humans are making other types of decisions. In contrast, the ventromedial prefrontal cortex, a brain region that lacks any signals pertinent to foraging, encodes choice values in a manner uninfluenced by environmental richness.