, 1997). Noonan et al. (2010) report just such an effect (Figure 4A). The lesions were made in the medial orbitofrontal cortex in macaques, in the region Mackey and Petrides (2010) argue corresponds to the human reward-related vmPFC/mOFC region (Figure 2B). The vmPFC/mOFC reward signal in human fMRI studies is often discussed in the context of neural recordings and lesion studies of the orbital cortex of macaques and rats (Murray et al., 2007). The focus of studies conducted in SB203580 mw animals, however, is often on the more accessible lOFC rather than the vmPFC/mOFC itself. Although there

is evidence that neurons on the orbital surface of the frontal lobe encode the value of offered and chosen rewards (Tremblay and Schultz, 1999, Padoa-Schioppa and Assad, 2006, Kennerley et al., 2009 and Morrison and Salzman, 2009) the majority of recordings are made in the tissue that lies lateral to the medial orbital sulcus in the lOFC. Comparatively little is known of the activity of single neurons in vmPFC. The lOFC has distinct anatomical connections to vmPFC/mOFC selleck kinase inhibitor that suggest it has access to different types of information and is able to exert different types of influences on the rest of the brain; in other words, its functions are likely to be distinct

(Ray and Price, 1993, Carmichael and Price, 1994, Carmichael and Price, 1995a, Carmichael and Price, 1995b, Carmichael and Price, 1996, Ongür et al., 1998, Ferry et al., 2000, Kondo et al., 2003, Kondo et al., 2005 and Saleem et al., 2008). One influential idea is that lOFC and vmPFC/mOFC are relatively more concerned with negative and positive outcomes, respectively (O’Doherty et al., 2001). There have certainly been frequent replications of the finding

that vmPFC/mOFC activity is higher when reward outcomes are received for choices while lOFC activity is higher after punishment or on error trials when potential rewards are not given (Kringelbach and Rolls, 2004). As we have already seen, however, one problem for the reward versus error view of vmPFC versus lOFC is that vmPFC/mOFC appears sufficient to signal both aversive and STK38 rewarding value expectations (Tom et al., 2007 and Plassmann et al., 2010). Even more problematic for a view that emphasizes the separation of appetitive and aversive outcomes in OFC is evidence that information about both converges on the same OFC neurons. Morrison and Salzman (2009) reported no anatomical separation within the orbitofrontal area bounded by the medial and lateral orbitofrontal sulci, in neurons that responded to aversive and appetitive outcomes, such as air puffs and juice rewards, respectively. They even found neurons that responded to both types of outcome and that responded to conditioned stimuli predictive of either type of outcome.