The role of the orbitofrontal cortex in the pursuit of happiness and more specific rewards

Abstract

Cues that reliably predict rewards trigger the thoughts and emotions normally evoked by those rewards. Humans and other animals will work, often quite hard, for these cues. This is termed conditioned reinforcement. The ability to use conditioned reinforcers to guide our behaviour is normally beneficial; however, it can go awry. For example, corporate icons, such as McDonald's Golden Arches, influence consumer behaviour in powerful and sometimes surprising ways 1 , and drug-associated cues trigger relapse to drug seeking in addicts and animals exposed to addictive drugs, even after abstinence or extinction 2,3 . Yet, despite their prevalence, it is not known how conditioned reinforcers control human or other animal behaviour. One possibility is that they act through the use of the specific rewards they predict; alternatively, they could control behaviour directly by activating emotions that are independent of any specific reward. In other words, the Golden Arches may drive business because they evoke thoughts of hamburgers and fries, or instead, may be effective because they also evoke feelings of hunger or happiness. Moreover, different brain circuits could support conditioned reinforcement mediated by thoughts of specific outcomes versus more general affective information. Here we have attempted to address these questions in rats. Rats were trained to learn that different cues predicted different rewards using specialized conditioning procedures that controlled whether the cues evoked thoughts of specific outcomes or general affective representations common to different outcomes. Subsequently, these rats were given the opportunity to press levers to obtain short and otherwise unrewarded presentations of these cues. We found that rats were willing to work for cues that evoked either outcome-specific or general affective representations. Furthermore the orbitofrontal cortex, a prefrontal region important for adaptive decision-making 4 , was critical for the former but not for the latter form of conditioned reinforcement.

Stress induced risk-aversion is reverted by D2/D3 agonist in the rat

“…The OFC is critically involved on assigning and updating reward values, encoding a wide range of other variables indispensable for decision-making, including expected outcomes (Schoenbaum et al, 1998), effort associated to each option (Kennerley et al, 2009;Roesch and Olson, 2005), confidence in the decision (Kepecs et al, 2008) and the probability of win (Kennerley et al, 2009). Interestingly, rodent lesion studies have highlighted that the OFC encodes specific information about the outcome rather than its general affective value (Burke et al, 2008). Additionally, we had previously shown that chronic stress biased behavior from goal-directed to habit based choices, which was mediated by a shift from an atrophied medial prefrontal loop to a hypertrophied orbitofrontal network (Dias-Ferreira et al, 2009).…”

Fiber connectivity between the striatum and cortical and subcortical regions is associated with temperaments in Chinese males

“…The OFC has been found to play an important role in reward processing (Burke et al, 2008;Assad, 2006, 2008). It is believed to form relative reward values to guide or top-down regulate human RD-oriented behaviors during reward processing (Rolls, 2000;Wallis, 2007).…”

Identity-specific coding of future rewards in the human orbitofrontal cortex

“…Recent data suggest that the OFC is involved in signaling information about specific outcomes (9)(10)(11)(12)(13)(14). For instance, many OFC neurons signal both the value and the identity of the predicted outcome (12), and OFC lesions diminish the effects of outcome identity (but not general affective value) on conditioned behavior (13).…”