Choice and addiction

I just listened to this podcast on choice. I’m only half way through and, so far, it has said nothing about addiction, but it’s content is very relevant to addiction.

First, a little background. We know that the limbic system and frontal cortex both play important roles in addiction. The limbic system (The primitive part of the brain that controls drives for food and sex. It’s the “go” part of the brain.) responds very strongly to drug cues in drug addicts, and the frontal cortex (The rational part of the brain that weighs the pros and cons of decisions. It might be thought of as your brain’s brakes that help prevent you from making impulsive decisions.) appears to be impaired in drug addicts. Loss of control is attributed to this disrupted balance between the limbic system and the frontal cortex.

Back to the radio show. In the first segment, it talked about an experiment that seems to demonstrate the power of this disrupted balance. Subjects were led into a room one by one and given a number to remember. One group was given a 2 digit number and the other group was given a 7 digit number. They were asked to report to another room down the hall and recite the number to the researcher in the other room. On their way to the other room they were stopped by someone offering them a snack–a choice between a piece of chocolate cake and an apple. The subjects who were given a 2 digit number overwhelmingly chose an apple and the subjects who were given a 7 digit number overwhelmingly chose the cake.

Why? Here are 3 assumptions that the researchers made when explaining the results:

  1. That cake is the prefered snack of the “emotional brain”–it’s tasty and sweet. I’m assuming that emotional brain and the limbic system are the same or overlap.
  2. That an apple is the preferred snack of the rational brain–it’s healthy and you won’t have any regrets.
  3. The remembering 7 digits places demands on the rational brain. It is the part of the brain involved in remembering this kind of information on a short term basis.

The researchers believe that the subjects trying to remember 7 digits chose chocolate cake because their rational brain was focused on remembering the numbers and was not able to fully engage in the snack decision to steer the person toward the healthy low-regret snack.

Think about that for a minute.

These are subjects with healthy, normal limbic systems and frontal cortexes. This relatively minor distraction had a significant impact on subject choices. Imagine people with ramped up emotional brains and impaired rational brains. The loss of control in addiction becomes easier to comprehend.