Because purchasing decisions are primarily about personal value, about how much we gain or lose, the prefrontal cortex does not seem to be the dominant player in our brain’s response to purchasing decisions. According to a 2007 fMRI experiment by Brian Knutson, George Lowestein, and colleagues, the frontal cortex was less activated during purchasing decisions than either the nucleus accumbens (which processes rewards), or the insula (which processes pain). This suggests that purchasing decisions are driven more by the balance of pain and desire than by a rational assessment of our options.