Cerebral Cortex Advance Access published online on May 12, 2009
Cerebral Cortex, doi:10.1093/cercor/bhp092
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Hedonic and Informational Functions of the Human Orbitofrontal Cortex
Neuroscience and Psychiatry Unit, University of Manchester, Manchester M13 9PT, UK
Address correspondence to Dr Rebecca Elliott, Neuroscience and Psychiatry Unit, Room G907, Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PT, UK. Email: rebecca.elliott{at}man.ac.uk.
Functional imaging studies have revealed roles for orbitofrontal cortex (OFC) in reward processing and decision making. In many situations, rewards signal that the current behavior should be maintained, whereas punishments cue a change in behavior. Thus, hedonic responses to reinforcers are conflated with their function as behavioral cues. In an attempt to disambiguate these functions, we performed a functional magnetic resonance imaging study of a 2-choice decision-making task. After each trial, subjects were rewarded or punished and independently provided with a cue to maintain or change behavior. We identified key regions of OFC involved in these processes. An anterior medial focus responded to reward, whereas bilateral lateral foci responded to punishment. The right-sided lateral region that responded to punishment also responded to cues for behavior change (shift), whereas a more ventral and anterior bilateral region responded to cues for behavioral maintenance (stay). The right-sided stay region responded specifically when stay cues were combined with punishment. These results support the view that OFC codes both hedonic responses to reinforcers and their behavioral consequences. Punishments and shift cues are associated with the same right lateral OFC focus, suggesting a fundamental connection between emotive response to negative reinforcement and use of negative information to cue behavioral change.
Key Words: fMRI orbitofrontal cortex reinforcement reward