In my last post, I explained a little bit of how addiction works in our brains. For addiction to occur, we must have had to have taken the addictive substance in first place, something many people, such as Peter Hitchens you may remember, regard erroneously as a choice that is worthy of punishment. Let’s look at how our brains make decisions and see if we agree with Mr. Hitchens, or if we have a different opinion.
Decision making is a quite complex process involving communication of multiple functional brain regions. When I say “functional brain regions”, it means that different areas of the same structure may carry out different functions. So, the prefrontal cortex, for instance, plays a role in many different executive functions, such as decision making, which require many different computations. Different computations are carried out in different parts of the PFC. Usually, we refer to areas within a structure directionally.
One particular functional region, the ventromedial (“ventro” meaning towards the underside of the brain, “medial” referring to the middle) prefrontal cortex, or vmPFC, works in concert with the OFC to compute predicitons of the consequences of our decisions.
Using this knowledge, we can locate our vmPFC within the prefrontal cortex:
Hopefully, this makes learning neuroanatomy much easier, as well as adds some impressive neurojargon to your already booming knowledge of the brain.
Using a test of called the Iowa Gambling Task, researchers can test the decision making ability of subjects. The subject must work through decks of cards which yield rewards, but may, at times, result in penalities. To see an absurdly jacked dude demonstrate the IGT, check out this video.
Eventually, healthy subjects are able to learn which decks are “good decks” that yield the best overall gains. It has been shown, however, that those with damage to either the vmPFC or OFC make lower-quality decisions. Damage to the vmPFC often results in subjects seeking short-term gains, despite heavy, long-term losses, whereas damage to OFC results in staying with “bad decks”, despite knowing that they’re bad.
The development and function of our brains is based on both genetic and environmental factors. Genetic predisposition accounts for roughly half of risky and impulsive behavior. Couple that with environmental factors, such as being raised in an environment where drug use is prevalent or endurance of trauma that make intoxication more attractive than reality, and we may now more easily understand why someone would make such a choice in the first place. Keep in mind that these predispositions are not chosen by individuals: we did not choose our genes, nor did we choose to be raised in whichever environment we were raised in, nor to experience whatever it is we have experienced.
Though it is indeed possible to have a life where drug and alcohol exposure are evitable, it is extremely improbable, not to mention such a person would be shut out from much of a broad range of life experience, such as parties or eating at restaurants – not much of a life, is it?
So, now we understand how bad choices are made and we have seen what addicted brains look like. Next, we’ll look into the process of recovery from addiction and what the best (as well as the worst) methods are for dealing with these issues. Then we’ll think about which social and legal policies would be most effective to deter drug use and treat substance abusers.
This will be addressed in future posts, so be sure to subscribe, either via email or on WordPress to receive notifications about these posts. Be sure to comment with any questions, corrections, opinions, etc. And feel free to share this with anyone you know who isn’t sure why they have difficulty with decisions such as gambling or make bad investments and doesn’t know about their vmPFC.