The Model Of The 3 Brains: Reptilian, Limbic And Neocortex
The human brain is the most complex system known. This means that, if you want to understand its operation, it is necessary to find patterns and regularities in its operation 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 various regions of the brain into different groups that, as this neuroscientist proposed, perform different tasks. The differentiated structures would be, according to MacLean, the reptilian complex, the limbic system and the neocortex.
The Model of the Three Brains presents a fascinating framework for understanding the complexities of the human brain and its functioning. Developed by neuroscientist Paul MacLean in the 1960s, this model proposes that the human brain consists of three distinct regions, each with its own evolutionary history, functions, and influences on behavior. In this article, we embark on a journey to explore the intricacies of the three-brain model, shedding light on its implications for psychology, neuroscience, and everyday life.
Paul MacLean’s triple brain idea is based on the idea that Three different brain systems live in the human brain, with their own operating logic, and that each of them has appeared in our evolutionary line sequentially, one on top of the other. This means, among other things, that these three brains would be relatively independent and that they would relate to each other following a hierarchy, depending on their age 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 that appeared most recently in The evolutionary line that leads to Homo sapiens would be the one in charge of the most refined and complex functions.
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 relative independence from each other, although they affect each other. He also recalls the idea that the emotional and the rational are part of two diametrically opposed psychological dimensions, and that where there is one, the other does not fit.
The parts of the brain according to Paul MacLean
Now that we have briefly reviewed the ideas on which the triune brain model is based, let’s look at its parts separately:
Reptilian Brain (Brainstem and Basal Ganglia)
The reptilian brain, also known as the primitive or instinctual brain, represents the oldest and most primitive region of the human brain. It encompasses the brainstem and basal ganglia and is responsible for regulating essential functions such as breathing, heart rate, and basic survival instincts. Derived from the brain structures of early reptiles, the reptilian brain governs instinctual behaviors associated with survival and self-preservation.
For Paul MacLean, The concept of the reptilian complex served to define the lowest area of the forebrain, where the so-called basal ganglia are located, and also areas of the brain stem and cerebellum responsible for maintaining the functions necessary for immediate survival. According to MacLean, these areas were related to the stereotyped and predictable behaviors that according to him define poorly 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: fear, 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.
Limbic System (Mammalian Brain)
The limbic system comprises structures such as the amygdala, hippocampus, and hypothalamus, collectively known as the “emotional brain.” Evolving from the brains of early mammals, the limbic system plays a central role in processing emotions, forming memories, and regulating physiological responses to stress. It is intricately involved in various aspects of social behavior, attachment, and emotional processing, shaping our subjective experiences and interpersonal interactions.
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 occurs again, while if it produces pain, we will remember that experience and avoid having to experience it again. Thus, this component would have a fundamental role in processes such as classical conditioning or operant conditioning.
Neocortex (Human Brain)
The neocortex, often referred to as the “thinking brain,” is the most recently evolved and distinctly human region of the brain. It encompasses the cerebral cortex, responsible for higher-order cognitive functions such as reasoning, language, decision-making, and complex problem-solving. The neocortex enables humans to engage in abstract thinking, planning for the future, and executing sophisticated behaviors, distinguishing us from other species and underpinning our capacity for culture and civilization.
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 due to biology itself, the neocortex was permeable to all kinds of subtleties coming from the environment and the analysis of our own actions.
For this neuroscientist, The neocortex could be considered the seat of rationality in our nervous system since it allows us the emergence of systematic and logical thinking, which exists independently of the emotions and behaviors programmed by our genetics.
Interactions Among the Three Brains
Hierarchical Organization
The three brains are interconnected through complex neural pathways, forming a hierarchical organization that influences behavior and cognition. While the reptilian brain governs fundamental survival instincts and reflexive behaviors, the limbic system adds emotional richness and context to our experiences, shaping our responses to stimuli based on past learning and emotional associations. The neocortex, situated atop this hierarchy, exerts executive control and regulation, integrating sensory input, emotions, and rational thought to guide decision-making and behavior.
Each brain region contributes unique influences to our behavior, often operating in concert to produce adaptive responses to environmental demands. For example, when faced with a threat, the reptilian brain initiates a fight-or-flight response, triggering physiological changes to enhance survival. The limbic system modulates this response by evaluating the emotional significance of the threat and guiding subsequent actions based on past experiences and learned associations. The neocortex, meanwhile, evaluates the situation, weighs potential outcomes, and formulates a strategic response informed by rational analysis and foresight.
Implications for Psychology and Neuroscience
Understanding Human Behavior
The model of the three brains provides a nuanced framework for understanding the complexities of human behavior, offering insights into the interplay between instinctual drives, emotional responses, and cognitive processes. By considering the contributions of each brain region, psychologists and neuroscientists can elucidate the underlying mechanisms governing behavior and develop interventions to address psychological disorders and maladaptive patterns of thinking and behavior.
Emotion Regulation and Well-being
The limbic system’s central role in emotion regulation underscores its significance for mental health and well-being. By enhancing our awareness of emotional triggers and cultivating strategies for managing stress and regulating emotions, individuals can foster resilience and psychological flourishing. Mindfulness practices, cognitive-behavioral techniques, and therapeutic interventions aimed at promoting emotional intelligence and self-regulation draw upon insights from the model of the three brains to empower individuals in navigating the complexities of their inner worlds.
Application in Everyday Life
Personal Development and Self-awareness
Understanding the model of the three brains can empower individuals in their personal development journey by fostering self-awareness and insight into their thought patterns, emotions, and behaviors. By recognizing the influence of instinctual drives, emotional responses, and cognitive processes, individuals can cultivate greater agency and autonomy in navigating life’s challenges and pursuing their goals. Practicing self-reflection, emotional regulation techniques, and mindfulness exercises can facilitate personal growth and enhance overall well-being.
Interpersonal Relationships
Insights from the three-brain model can also enrich interpersonal relationships by fostering empathy, understanding, and effective communication. By recognizing the diverse ways in which individuals process information and experience emotions, individuals can cultivate greater empathy and compassion towards others, fostering harmonious relationships built on mutual respect and understanding. Strategies such as active listening, perspective-taking, and conflict resolution draw upon principles derived from the model of the three brains to promote healthy and fulfilling interactions with others.
The three brain model and marketing
The idea that we have a reptilian brain, a limbic brain and a rational brain has long seduced many people dedicated to the world of advertising, market research and marketing. The triune model allows us to separately consider three areas of people’s psychological lives that are very easy to learn and internalize: a rational instance, an emotional one, and an impulsive one.
This has meant that in recent decades the interest of advertising campaigns has focused on appealing to the reptilian and limbic brain, but not the rational one: 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, produce more powerful purchasing needs, given their importance and their hierarchical position as parts of the brain that are more important than the neocortex. Advertisements and marketing campaigns have gone from thinking of the customer as an agent who needs to be informed about the characteristics of the product to decide rationally according to their interests to trying to touch people’s sensitive chords to sell them a sensation associated with the product. more than the product itself.
And the truth is that this change of approach is considered a great success; Unlike what happened in the 1960s, 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 particular product are told. lifestyle that we want to make ours. Ignoring the logic of the rational brain and focusing on emotions and basic desires is proving so profitable that even products as expensive as perfumes or cars are promoted that way.
MacLean’s theory in neuroscience, today
However, beyond what happens in the business world, in neuroscience and in evolutionary biology The three-brain model is considered outdated, among other things, because it understands the development of the brain as a construction process of “pieces” that have been assembled on top of each other and that execute certain tasks by themselves. Today it is believed the opposite: that in the functioning of the brain, the function that the parts of the brain perform alone do not matter as much as the way in which they connect to each other to work together and in real time.
Furthermore, as far as is known, evolution does not cause new components to be integrated into the old ones, as is, without altering them. Every time a mutation causes a trait to become widespread, alters the functioning of the entire body and the way in which the parts that had evolved before work are not limited to “expanding” capabilities. That is why the idea that brain organs “in charge of the rational” are coupled with the previous ones has not been well accepted.
Furthermore, the functions that each of the three brains supposedly performed well define the characteristic behavior of the groups of animals that, according to him, represent the moment of evolution in which these structures appeared. On the other hand, today we know that the basal ganglia (which would form part of the reptilian brain) have nothing to do with the execution of genetically programmed actions, but are associated with the performance of voluntary movements that, after having been practiced a lot, They have become automatic, like riding a bicycle.
The model of the three brains offers a compelling framework for understanding the intricate interplay between instinctual drives, emotional responses, and cognitive processes in shaping human behavior and cognition. By elucidating the evolutionary origins and interactions among the reptilian, limbic, and neocortical regions of the brain, this model provides valuable insights into the complexities of human nature and the underlying mechanisms governing behavior. Whether applied in the realms of psychology, neuroscience, personal development, or interpersonal relationships, the model of the three brains serves as a powerful tool for enhancing our understanding of ourselves and others, fostering growth, resilience, and well-being.
