Most people would consider the experience of breaking a bone or eating something particularly tasty as being essentially different from the experience of a simple or complex social event in which one is accepted or rejected. I think most people would think that the experience of the latter would depend on your interpretation of the event whereas the experience of the former is baked into the actual physical event.
In the human brain, the pain network consists of dorsal anterior cingulate cortex (dACC), insula(Ins), somatosensory cortex (SSC), the periaqueductal grey (PAG), and thalamus (Thal). The pleasure or reward network consists of the ventral tegmental area (VTA), ventral striatum (VS), ventromedial prefrontal cortex (VMPFC) and the amygdala (Amyg). The first is implicated in the physical and social pain process and the second is implicated in the social and physical reward process.
Takahasi and colleagues have thrown a big question mark into our standard formulation of experience of pleasure or pain with their paper in the February 13 2009 issue of Science showing that experiencing envy at another's success activates pain-related circuitry, whereas experiencing schadenfreude (happiness at another's misfortune or loss) activates reward -related neural circuitry. In other words, experience of pain or pleasure from psychological/social or physical events share the same circuits. The findings suggest that the brain treats abstract social events and physical events in a more similar manner that is usually assumed.
They did two functional magnetic resonance imaging (fMRI) studies. The first study involved reading about a target person whose levels of possession was superior and whose self-relevance was high leading to the experience of envy and as one would predict stronger anterior cingulate cortex (ACC) activation. In the second study, misfortunes happened to envied persons and as one would predict ventral striatal activation occurred. These findings demonstrate neurocognitive mechanisms of envy and schadenfreude: the activation of pain network for envy and reward network for schadenfreude.
Physical pain and social pain activate the same networks. Being socially outcast, being treated unfairly, of grieving activates the dACC and insula and the ACC showing an activation proportional to the level of social pain experienced. On the other hand , being treated fairly, being a cooperative team member, being admired, or making charitable contributions activates the ventral striatum. These are further indications that the human brain treats abstracted social experience as more similar to physical experience that we generally assume.
Is there a connection between these findings and the everyday notion that inability to gratify certain needs produces pain and their gratification produces pleasure? Thus is the motivation for many activities -- seeking food, water, shelter, safety , etc. Might these social experiences also occupy a similar motivational niche? If we look at John Bowlby's work on attachment, we would conclude that it is the social contact of a relatively immature human infant that allows for the satisfaction of physical needs. Neuroscience would seem to be saying that the social world is important and is vital part of the adaptive response favored by natural selection.
While I am no expert in this field, I believe Takahashi and colleagues have produced the first showing of this very important finding. This is a blockbuster piece of work.