[The following is an exact transcript of this podcast.]

[Judge’s voice: Members of the jury, do you have a verdict?]

When it comes to making decisions about innocence and guilt, the human brain acts as both judge and jury. Now a study published in the journal Neuron shows that, just like in the courtroom, the brain’s judge and jury sit in separate places.

When someone’s put on trial, two types of decisions have to be made. First, is the person guilty? And second, what punishment, if any, does that person deserve? Scientists at Vanderbilt University got to wondering how the brain actually makes those two different decisions. So they used functional MRI to monitor the brain activity of subjects as they read about various crimes, and decided how severely the perpetrators should be punished, or whether they should be punished at all.

What the researchers found is that a brain region involved in analytical thought was most active when the subject was deciding whether the perpetrator was actually guilty. But a different area, one more in tune with emotion, weighed in on how to make the punishment fit the crime. The study was funded by the MacArthur Foundation Project on Law and Neuroscience, and it suggests that when it comes to crime and punishment, we may be impartial but we’re not without passion.

—Karen Hopkin

Announcer: For more on the MacArthur Foundation’s Law and Neuroscience Project, check out the November 27th, 2007, episode of Science Talk, the weekly podcast of Scientific American, at SciAm.com/podcast 

60-Second Science is a daily podcast. Subscribe to this Podcast: RSS | iTunes 

60-Second Science is a daily Podcast. Subscribe to this Podcast: RSS | iTunes