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Sunday, April 26, 2009

Are you Impulsive

We had a great lecture this week from a world expert psychiatrist on impulsive behavior and it was very enlightening and frightening at  the same time. What is impulsive behavior? To keep things simple I will explain the concepts without all of the medical jargon. Basically and impulse is a thought about doing something. Impulsive behavior is often defined when pathologic as the inability to define or evaluate a behavior / action in the context of its environment. Imagine sitting in a lecture and you suddenly feel like taking your pants off. Hopefully with your functioning brain you would realize that in the given environment it would be inappropriate to take your pants off and thus you would refrain from taking your pants off. In a different environment it may be perfectly acceptable to take your pants off; like in a dressing room or a locker room or in your bedroom. All of this modulation of behavior and ultimately the action or refrain from action is mostly carried out on a subconscious level meaning you are completely unaware of this occurring in your brain and it occurs in milliseconds.

Over the years there have been many studies and experiments to study impulsive behavior and why some struggle with it while other do not. Through imaging healthy individuals and impulsive patients why they do certain exercises it has been determined that most of the control of impulsive behavior occurs in the frontal lobes. The specific neurotransmitters involved in the process have also been identified. Once this was figured out scientist have been able to alter these transmitters in people and cause impulsive behavior in otherwise non-impulsive individuals. 

There was a study done where several healthy individuals had there frontal lobe neurotransmitters manipulated to create impulsive behavior. The scientist told each of the patients that they would walk down a hallway and turn to the left and on a shelf they would find money. They were instructed not to take the money and they all agreed not take the money. The study group with the altered neurotransmitters nearly all took the money even though they said they would not and had agreed to not take the money. The control group had no problem not taking the money. They left the money alone. In the same experiment patient with impulsive behavior disorders almost always take the money. In the interview with the normal patients who had their neurotransmitters temporarily altered for the experiment could not explain why they took the money. They knew that they were not supposed to take the money and had planned on not taking the money but somehow when they saw the money they acted without any control. 

Also when you study teenagers brains we see on imaging studies that their immature brains lack the full ability and neurotransmitter stability to inhibit impulsive behaviors. We also know that alcohol disturbs the balance of the neurotransmitter necessary to inhibit impulsive behavior. In thinking about evolution you must ask why has impulsive behavior survived all these years if it is detrimental to humans. There must be a protective aspect to it or we would not continue to have the impulsive behavior. All healthy brains have the ability to modulate the neurotransmitters in such away that they turn off the inhibition center allowing impulsive behavior to flow freely. This is protective in many circumstances. For example in times of danger like hitting black ice while driving we are able to act without thinking, we impulsively steer the car out of the spin and in the proper direction often preventing disaster. When things like this occur our inhibition center for impulsive behavior is turned off or less active allowing for the protective impulsive behavior to take over. There are many more examples of situations where a person may need impulsive behavior for protection. 

Everyone has times in their life where they may act impulsively in a good way and sometimes in a bad way. I know I have had times in my life where I said or did something only to wonder why I could not control myself in that situation and I vow to not make the same mistake in the future but then in that same enviornment in the future I make the exact same error again and again. Eventually I learn to control this or avoid the environment. I do not have a disorder or at least I have not been diagnosed with an impulsive behavior disorder and I can't imagine how difficult it must be for someone who has severe pathology leading to impulsive disorder.

This all leads to a question? Does an individual who has pathology in the inhibitory center for impulsive behavior have the ability to control these impulsive behaviors? Does he/she have free will with regards to these specific impulsive behaviors? 

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