Incentive Salience

Incentive Salience Can Motivate Destructive Behavior

There is a lot of debate about what exactly motivates people to act in certain ways. In particular, why is it that people sometimes engage in self-destructive behaviors such as addiction. Addicts may lose family, friends, and possessions, yet still they continue to abuse whatever substance they are addicted to. They may claim that they want to stop but feel powerless in the face of their addictive behavior. Even those individuals who manage to escape the abuse and build a good life in recovery may later relapse back to their destructive habits. How can this happen?

All humans will have things that they like, but dependence on alcohol or drugs goes beyond liking something. It is like these people are possessed by such a strong desire to use the drug. It is suggested that incentive salience is what motivates individuals to become substance abusers. This involves complex changes to their behavior and psychological functioning. This would also explain why so many former addicts and alcoholics relapse after a period of abstinence.

Incentive Salience Defined

Incentive salience is a type of motivation created in the brain because it has developed an association between a certain stimuli and reward. In the case of addiction this stimuli will be whatever drug the individual is using. Incentive salience is a far greater incentive than merely liking something. In fact it can happen that the individual no longer likes the drug but feels compelled to take it due to incentive salience. This compulsion to use is driven by unconscious forces. This association between the drug and reward can last even though the individual has been in recovery for many years.

Incentive Sensitization Theory of Addiction

The Sensitization Theory of Addiction has been produced by Dr. Kent C. Berridge and Dr. Terry Robinson. These two psychologists propose that the neural system becomes sensitized by the addictive substance. It is this that leads to incentive salience and the continued use of the substance. The brain of the addict is changed by their substance abuse and it is this that creates psychological processes associated with addiction. It is also what creates the constant desire for the drug. This desire can be a conscious craving or an unconscious one.

If susceptible individuals are repeatedly exposed to addictive substances it can change the way their brain operates. These individual become hypersensitive to the drug and this means that the substance can now stimulate neurobehavioral systems significantly more than before. The outcome of this change is that people start to receive increasing amounts of pleasure when they use alcohol or drugs. This leads to incentive salience and an increasing preconscious desire for the substance. As the individual takes more of the substance it only leads to more sensitization. The preconscious desire becomes a conscious obsession.

Learning Theory of Addiction vs. Incentive Salience

Learning theories of addiction are based on the idea that this type of behavior is learned. This suggests that all that is needed to cure the problem is to unlearn the behavior. If sensitization is part of the addiction process though, this means that it is not just a behavior that people learn. The compulsion is driven by incentive salience as well as learned behaviors.

It is argued that learning may be more associated with the rituals surrounding how the drug is consumed rather than the actual compulsion to use. Learning may determine the type of addiction, but it will be incentive salience which drives it. It is the fact that the individual’s brain has become sensitized to the substance that is the real problem. The Incentive Sensitization Theory does not discount the role of learning in addiction, but it does reduce its importance. The ideas of incentive salience also seem to argue against the conclusions of choice theory where all behavior is seen as chosen by the individual.

Incentive Salience and Addiction Recovery

Many of those individuals who enter recovery will later relapse. Incentive salience provides a possible explanation for why this happens. Even though the individual no longer takes the substance, and has made it through withdrawals, the sensitization to the drug will still be there. The effect of this is that the individual may still experience cravings for the substance or unconsciously continue to want it. If the person in recovery is aware of this then they are better able to guard against it.