Most of us have seen pictures of the human brain. But a chance to see your own and see what's going on inside is something magnetic resonance imaging - the MRI - has made possible. And lot of people are interested.

"Even the most hardened inmates men or women often go through a period where they're asking themselves is there something i could have done differently that would have kept me from being here, and we're trying to help figure out what that is," said Kent Kiehl, Phd, Mind Research Network.

That's why thousands of prison inmates have volunteered to have their brains scanned.

Dr. Kiehl and his team have taken their mobile MRI to eight prisons in Texas and New Mexico. More than 3500 inmates have gone through it.

"There's this whole part of the limbic system that runs right here. And this is the part that we're really interested in studying in psychopathy," said Dr. Kiehl.

Dr. Kiehl has studied the brains of psychopaths for decades, writing about it in his book released this year - "The Psychopath Whisperer."

His brain research has zeroed in on the amygdala, a structure involved in decision making and emotional response.

The amygdala is smaller in psychopaths. MRIs show that many violent offenders just don't get the same boost of activity. Dr. Kiehl is looking to understand the underlying causes abhorrent behavior, not to excuse it, but to find ways to treat it, perhaps develop drug or a program that can reduce the likelihood psychopaths will reoffend.

Especially in the youngest - where society questions - is there any hope for them?

"Like any system of the brain, it's very plastic and we think there's a lot of opportunity to make some changes," said Kiehl.

Dr. Kiehl points to a Wisconsin program that used brain research to develop a model of rewarding young criminals for good behavior - rather than punishing bad behavior, and it's seeing some success.