Today, I have some neuroanatomy for you: prefrontal cortex.
Mmmm…goes down smooth.
What is a prefrontal cortex (PFC)? This is an area of your cerebral cortex located in the frontal lobe that carries out what neuroscientists will often refer to as “executive functions.” These include mood and action regulation, working memory, attention, etc.
Let’s discuss action regulation. Have you ever had a thought you didn’t want to have, or perhaps were not so bothered by having, but simply would never act upon? That’s because your PFC shuts down your urges. It makes sense then that reductions in prefrontal volume, as well as low connectivity of the PFC with other brain regions has been seen in criminal populations. Some people simply have a reduced capacity not to do bad things. Causes of this include life stressors, lead poisoning and cancer.
Let’s take a look at a case study (in science, case studies are studies involving only one individual, usually a patient, presented with a very unique condition form which something new may be learned) of a healthy 40 year-old man, who, though he had an existing interest in pornography, was married, with a stepdaughter and had no record of crime or significant misconduct in his past. It was noted in the case study that his interest in porn did not involve children and had no impact on his marriage. Unexpectedly, he started to feel sexually attracted to children and eventually, was so overcome by his urges that he advanced on his prepubescent stepdaughter. He was then arrested and removed from the home.
The night before he was supposed to receive his sentence, he visited a hospital complaining of a headache. In addition, he showed other worrying signs, such as a fear he would rape nurses and suffered from much distress as he knew how wrong his compulsions were, yet couldn’t help but act on them. Thus, a brain scan was performed which showed a tumor located in his orbitofrontal cortex, an area of the PFC involved in the regulation of social behavior.
His tumor was removed and his urges subsided. His wife forgave him and the judge allowed him to move back in with his family.
A year later, he started collecting child pornography and again went back to the oncologist. Another scan revealed that the tumor has grown back a bit. This is not uncommon, especially with brain cancer where surgeons need to be careful not to remove any actual brain tissue during resection (removal) of the cancerous tissue.
Again his tumor was removed and again his urges subsided.
In this case, it was rather obvious that punishing the man and convicting him as a criminal pedophile would be inappropriate as well as ineffective. However, it still raises some profound questions.
What about those who may not have an obvious tumor obstructing their PFC, but rather were malnourished or suffered early life stress or even had an injury in which the damage was seemingly subtle? How in command of our own actions are we?
Here, we’re scratching the surface of new fields of study. Neurolaw, which studies how neuroscience could help and improve our legal system, and neurocriminology which studies the biological (as well as social) causes for crime, are two important fields emerging from this brand of knowledge.
If you’re interested in reading more about these issues, here’s a few recommendations:
- David Eagleman’s Incognito – about the subconcious activity of your brain – how much control do you really have?
- Adrian Raine’s The Anatomy of Violence – a must read; great way to learn about gene/environment interaction
- Sam Harris’ Free Will – you either love him, hate him, or you’ve never heard of him; best points I’ve seen made on the topic; with degrees in philosophy and neuroscience, he uses both to deconstruct the notion that we have free will
- I haven’t yet checked out Mark Balaguer’s Free Will, but I’ve been meaning to. He seems to offer a rebuttal to Harris while concluding that there is inconclusive evidence for the existence of free will. If anyone has read this yet, let me know what you thought.
So, what do you think?