Brain Reward System: What Is It And How Does It Work?
The functioning of the human brain may seem chaotic due to its complexity but the truth is that everything that happens in it obeys a logic: the need for survival.
Of course, such an important issue has not been left unattended by natural selection, and that is why our nervous system includes many mechanisms that allow us to stay alive: the regulation of body temperature, the integration of visual information, the control of breathing, etc. All these processes are automatic and we cannot intervene voluntarily on them.
But… what happens when what brings us closer to death has to do with actions learned through experience? In those cases, which are not foreseen by evolution, an element known as the brain’s reward system acts
The reward system is a set of mechanisms carried out by our brain that allows us to associate certain situations with a feeling of pleasure. In this way, from those learnings We will tend to try to ensure that in the future the situations that have generated that experience occur again
In some way, the reward system is what allows us to locate objectives in a very primary sense. As human beings are exposed to a wide variety of situations for which biological evolution has not prepared us, these mechanisms reward certain actions over others, causing us to learn as we go what is good for us and what is not. is.
Thus, the reward system is closely linked to basic needs: it will make us feel very rewarded when finding a place that contains water when we have not drunk for too long, and it will make us feel good when we strengthen ties with someone friendly.
Its function is to ensure that, whatever we do, and no matter how varied our actions and behavioral options may be, we always have as a reference a compass that consistently points towards certain sources of motivation, instead of anywhere.
Where does the reward circuit go?
Although everything that happens in our brain happens very quickly and receives feedback from many other regions of the nervous system, to better understand how the reward system works, its operation is often simplified by describing it as a circuit with a clear beginning and end: the mesolimbic pathway, characterized among other things by the importance of a neurotransmitter called dopamine.
The beginning of this information transmission chain is located in an area of ​​the brain stem called the ventral tegmental area. This region is related to basic survival mechanisms that are automated with the lower part of the brain, and from there they go up to the limbic system, a set of structures known to be responsible for the generation of emotions. Specifically, The nucleus accumbens is associated with the appearance of the sensation of pleasure
This mixture of pleasant emotions and a sensation of pleasure passes to the frontal lobe, where the information is integrated in the form of more or less abstract motivations that lead to planning sequences of voluntary actions that allow us to get closer to the goal.
Thus, the reward circuit begins in one of the most basic and automated places in the brain and goes up to the frontal lobe, which is one of the places most related to learning, flexible behavior and decision making.
The dark side: addictions
The reward system allows us to continue to be connected to a sense of pragmatism that allows us to survive while we can choose between various options of action and we do not have to stick to automatic and stereotyped behaviors determined by our genes (something that happens, for example). example, in ants and insects in general).
However, This possibility of leaving us room for maneuver when it comes to choosing what we are going to do also has a risk called addiction Actions that are initially voluntary and completely controlled, such as the choice to try heroin, may become the only option we have left if we become addicted.
In these cases, our reward system will only be activated when consuming a dose, leaving us completely unable to feel satisfaction from anything else.
Of course, there are many types of addictions and the one that depends on heroin use is one of the most extreme. However, the mechanism underlying all of them is fundamentally the same: the reward center is “hacked” and becomes a tool that guides us towards a single objective, making us lose control over what we do.
In the case of substance consumption, certain molecules can directly interfere with the reward circuit, causing it to undergo a transformation in a short time, but Addictions can also appear without drug use, simply from the excessive repetition of certain behaviors In these cases, the substances that produce changes in the reward system are neurotransmitters and hormones generated by our own body.
The study of the reward system makes us wonder where the limit is between addiction and normal behavior In practice it is clear that a person who sells all his belongings to sell drugs has a problem, but if we take into account that addictive behaviors can appear without taking anything and that they are produced from the functioning of a brain system that operates in all people constantly, it is not easy to establish the threshold of addiction.
This has led, for example, to talk about love as a kind of relatively benign addiction: the reward system is activated when we interact with certain people and stops responding as much when they are no longer present, at least for a while. Something similar happens with addiction to mobile phones and the Internet: perhaps if we do not take it very seriously it is simply because it is socially accepted.
