Neuron 65, 845–851 (2010)

Previous work has shown that people with damage to a brain region called the ventromedial prefrontal cortex (VMPC) — which is involved in processing emotions — choose the 'utilitarian' option when presented with moral dilemmas. For example, they would opt to harm one person to save five. But what underlies their support of such actions?

Liane Young at the Massachusetts Institute of Technology in Cambridge and her co-workers asked nine patients with VMPC lesions to rate various scenarios on their moral permissibility. The scenarios portrayed a person committing an act with either a neutral or a harmful outcome, such as administering a possible poison, and specified whether the person intended harm.

The patients rated a failed attempt to harm as more permissible than an accidentally harmful act, showing that they neglect harmful intent, focusing more on outcome when making moral judgements. Their response contrasts with that of normal volunteers and people with damage to other brain regions, who had the opposite reaction.