David Eagleman is a neuroscientist and the head of the Centre for Science and Law in Houston, Texas. So, what do we do with somebody who gets a tumour and becomes a pedophile, and when the tumour is removed he's no longer a pedophile? Situations like that really complexify our notions of culpability. And we can imagine cases where people are killed, and then there's a tumour removed and the person is no longer the person he was when he committed the murder, and we haven't faced that case yet in courts, but it's coming soon, and in part we know that because brain imaging has become prevalent now.
Narrator: Brain imaging has made it possible for neuroscientists to study the criminal mind in greater detail than ever before. In Albuquerque, New Mexico, the Director of Science at the Mind Research Network, Kent Kiehl, studies the brains of psychopaths. He's interested in why they commit a disproportionate amount of violent and criminal acts. Psychopathy has been generally associated without conscience. The traits are synonymous with somebody having no guilt or remorse or empathy for what they've done. Narrator: Kiehl used magnetic resonance imaging or MRI machines to examine the brains of hundreds of psychopaths serving time in prison. He's created the largest database in the world. He's made some startling discoveries. Psychopaths' brains are very different from non-psychopathic or healthy brains. The brain is like a muscle. So, they basically have less muscle mass in those emotional regions of the brain. And we believe that contributes to the symptoms related to psychopathic traits, lack of empathy, inability to experience remorse or guilt, in grey matter in the thinking areas of the brain. In individuals with psychopathy we find that these green areas are showing a reduction in grey matter density, and so it's essentially like come out of the womb with not the same amount of tissue there, not the same amount of working matter there as, as the rest of us, and so this contributes to the development of those symptoms. We've also found that some of the tissues that connect the temporal lobe and the frontal lobe together are reduced, the wiring is thinner, which would suggest less connectivity between those regions, and that's, you know, a very important finding because it's believed to be, you know, very much a brain wiring issue, so that might be something they're born with. This is just three different planes, and so this is the front of the brain here, these are the eyes, right here, this is the orbital frontal cortex, and here are the two amygdala. So, it's these two structures and the connections between them that we have found are abnormal in individuals with psychopathy. Narrator: To test the implications of those findings, Kiehl is now using MRI to study how psychopathic brains react to different visual stimuli. Do they use emotional information, for example, the same way when you make a moral decision as other people do? Narrator: In one experiment, Kiehl flashes images that would trigger a strong emotional response in most people. In the vast 95% of us, 99% of us, when you process these emotional pictures you get a big emotional response in the brain, this limbic circuitry goes off. But in psychopaths it's just, like, dark. The feeling that comes along with it doesn't happen, so they have this kind of disconnection between emotion and decision-making. Narrator: So, what about the rest of us? Do we control our brains, or do our brains control us, and what's neuroscience telling us about how and why we make the decisions we make? We think that we know the reasons why we do what we do and why we believe what we believe, but, in fact, we have so little awareness of the vast machinery that we're sitting on top of. Narrator: Most of us believe that we're in conscious control of all our actions and every decision our brain makes. But David Eagleman says that's not the case.
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AuthorTim Sobers is a famous traveler and blogger, passionate camping and hiking lover. Tim is from Washington, D.C., US. He is also a writer at Students QA platform. ArchivesCategories |