3-brain model: reptilian, limbic, and neocortex

The human brain it is the most complex system known. That means that, if you want to understand its functioning, it is necessary to find patterns and regularities in its functioning and structure; In other words, we must try to formulate useful and simple explanations about this set of organs.

Paul MacLean's Triune Brain, which is sometimes known as the 3-brain theory, has been very popular for years for grouping several regions of the brain in different sets that, as proposed by this neuroscientist, perform tasks different. The differentiated structures would be, according to MacLean, the reptilian complex, the limbic system and the neocortex.

Understanding the idea of ​​triune brain

Paul MacLean's idea of ​​the triple brain is based on the idea that three different brain systems inhabit the human brain, with their own operating logics, and that each one of them has been appearing in our evolutionary line in a sequential way, one on top of the other. That means, among other things, that these three brains would be relatively independent and that they would be related among themselves following a hierarchy, depending on their seniority and the importance of their functions for our survival.

The reptilian complex, for example, being the first to appear would be the structure that carries out the most basic and most important functions to survive in the here and now, while the neocortex, being the structure of the most recent appearance in the evolutionary line that leads to Homo sapiens, would be the one in charge of the most refined and complex.

The logic that follows this conception of the human brain is very reminiscent of a way of understanding evolution as a process in which the new is accumulating on the old, so that these two parts maintain a relative independence from each other, although they affect each other. Also reminds of the idea that the emotional and the rational They are part of two diametrically opposed psychological dimensions, and where there is one there is no room for the other.

The parts of the brain according to Paul MacLean

Now that we've gone over the ideas behind the triune brain model, let's take a look at its parts separately:

1. The reptilian brain

For Paul MacLean, the concept of the reptilian complex served to define the lowest area of ​​the forebrain, where are the so-called basal ganglia, and also areas of the brain stem and cerebellum responsible for maintaining the functions necessary for immediate survival. According to MacLean, these zones were related to the stereotyped and predictable behaviors that according to him define the less evolved vertebrate animals, such as reptiles.

This structure would be limited to making simple and impulsive behaviors appear, similar to rituals that are always repeated in the same way, depending on the physiological states of the organism: afraid, hunger, anger, etc. It can be understood as a part of the nervous system that is limited to executing genetically programmed codes when the right conditions are met.

2. The limbic brain

The limbic system, which according to MacLean appeared with the most primitive mammals and on the basis of the reptilian complex, was presented as a structure responsible for the appearance of the emotions associated with each of the experiences that are lived.

Its usefulness has to do with learning. If a behavior produces pleasant emotions, we will tend to repeat it or try to change our environment so that it is produce again, while if it produces pain we will remember that experience and avoid having to experience it another time. Thus, this component would have a fundamental role in processes such as classical conditioning or the operant conditioning.

3. The neocortex

For MacLean, the neocortex was the most recent evolutionary milestone in the development of our brain. In this complex structure resided the ability to learn all the nuances of reality and to draw up the most complicated and original plans and strategies. If the reptilian complex was based on the repetition of processes entirely by biology itself, the neocortex was permeable to all kinds of subtleties coming from the environment and from the analysis of our own acts.

For this neuroscientist, the neocortex could be considered the seat of rationality in our nervous system, since it allows us the appearance of systematic and logical thinking, which exists independently of the emotions and behaviors programmed by our genetics.

The Three Brains Model and Marketing

The idea that we have a reptilian brain, a limbic brain, and a rational brain has long seduced time to many people dedicated to the world of advertising, market research and the marketing. The triune model allows us to consider separately three areas of the psychological life of the people who are very easy to learn and internalize: a rational instance, an emotional one, and another impulsive.

This has meant that in recent decades the interest of advertising campaigns has focused on appealing to the reptilian and limbic brain, but not to the rational: the reason is that, considering that these two are more rooted in our evolutionary history, they are easier to predict and, at the same time, they produce more powerful purchasing needs, given their importance and hierarchical position as more important pieces of the brain than the neocortex. Ads and marketing campaigns have moved from thinking of the customer as an agent who needs to be informed about the characteristics of the product to decide rationally according to your interests to try to strike a chord with people to sell them a feeling associated with the product, rather than the product per se.

And the truth is that this change of approach is considered a great success; Unlike what happened in the 60s, today it is very common to try to seduce potential buyers without talking about the characteristics of the product or its price: emotions are simply evoked or stories easily associated with a lifestyle we want are told make our. Bypassing the logic of the rational brain and targeting basic emotions and desires is proving so profitable that even expensive products such as perfumes or cars are promoted in such a way way.

MacLean's Theory in Neurosciences, Today

However, beyond what happens in the business world, in neuroscience and evolutionary biology the three-brain model is considered to be out of date, among other things, because he understands brain development as a process of construction by "pieces" that have been assembled one on top of the other and that execute certain by themselves chores. Today the opposite is believed: that the function of the brain does not matter so much in the functioning of the brain. parts of the brain alone such as how they connect to each other to work together and in time real.

In addition, as far as is known, evolution does not make new components integrate with the old ones, as is, without altering them. Every time a mutation makes a trait generalize, alters the functioning of the body as a whole And the way parts that had evolved before work are not limited to "expanding" capabilities. That is why the idea that cerebral organs "in charge of the rational" are coupled on the previous ones has not been well accepted.

In addition, the functions that each of the three brains were supposed to perform well define behavior. characteristic of the groups of animals that, according to him, represent the moment of evolution in which these structures. On the other hand, today we know that the basal ganglia (which would be part of the reptilian brain) do not have to do with the execution of programmed actions genetically, but are associated with the performance of voluntary movements that, after having been very practiced, have become automatic, such as going cycling.