A mindblog reader emailed me pointing out this (before MindBlog started up) 2005 publication by Bechara and collaborators on the role of emotion in making decisions in risky situations (rather relevant to our current financial crisis, with investors rushing like lemmings to emotionally drive the market in huge up or down swings). Disabling normal emotional reactivity by either brain lesions or substance abuse leads people to make more advantageous decision in risky situation. (In a 2009 post I noted Bechara's more recent work on reward processing in different parts of the brain.
Can dysfunction in neural systems subserving emotion lead, under certain circumstances, to more advantageous decisions? To answer this question, we investigated how individuals with substance dependence (ISD), patients with stable focal lesions in brain regions related to emotion (lesion patients), and normal participants (normal controls) made 20 rounds of investment decisions. Like lesion patients, ISD made more advantageous decisions and ultimately earned more money from their investments than the normal controls. When normal controls either won or lost money on an investment round, they adopted a conservative strategy and became more reluctant to invest on the subsequent round, suggesting that they were more affected than lesion patients and ISD by the outcomes of decisions made in the previous rounds.