The orbitofrontal cortex, predicted value, and choice


Bernard Balleine, BMRI, 100 Mallet St, Camperdown, NSW 2050, Sydney, Australia.


Considerable evidence suggests that choice between goal-directed actions depends on two incentive processes encoding the reward value of the goal or outcome and the predicted value of an action based on outcome-related stimuli. Although incentive theories generally assume that these processes are mediated by a common associative mechanism, a number of recent findings suggest that they are dissociable; the reward value of an action is derived from consummatory experience with the outcome itself, whereas the predicted value of an action is based on the presence of outcome-associated stimuli from which estimates of the likelihood of an outcome are derived. Importantly, the orbitofrontal cortex (OFC) in rodents appears to mediate the effect of outcome-related stimuli on choice; OFC lesions disrupt the influence of Pavlovian stimuli on choice in tests of outcome-specific Pavlovian-instrumental transfer. However, the influence of outcome-related stimuli on choice involves a larger circuit including the OFC, the ventral striatum, and the amygdala. How these structures interact, however, is not yet fully understood and is an important question for future research.