The Role Our Three Brains

“Three brains?” you might ask. “I have enough trouble managing one brain!”

In fact, the brain we know today that controls our every conscious and unconscious activity and behaviour has evolved and multiplied its capabilities over the millennia. What began as a very primitive brain focused on survival evolved over time through distinct stages into the complex, three-pound organism we know today.

Earlier, simpler brains were not replaced; rather, as the brain’s capacities developed, new brain evolutions wrapped themselves around earlier stages, which continued to function, and learned to interact with them.

The earliest brain to develop was the reptilian brain, responsible for survival instincts. This was followed by the mammalian brain, with instincts for feelings and memory. The final step in our brain’s development was the neocortex, the thinking part of the brain.

The most fully evolved animals—humans, primates and even dolphins—operate via all three of these developmental stages.

Here’s how the “three brains” are organized:

The Reptilian brain

The reptilian brain is made up of the brain stem and the cerebellum. Its purpose is fundamentally that of physical survival and maintenance—or homeostasis—of the body. The reptilian brain is basically all about me. It controls movement, breathing, circulation, hunger and reproduction. It is concerned with territory, social dominance, and questions of “fight or flight”: “Do I need to flee or fight?” and “Will it eat me or can I eat it?” Humans often experience these types of conflicting situations as stress.

In addition to real threats, such stress can result from the fact that the subconscious brain cannot differentiate between reality and imagination.

Our imagined projections—as well as real ones—can be the cause of fear and stress. Imagine waking up from a nightmare, sweating and fearful. The body has reacted to an imagined threat as if it were a real one.

The behaviours of the reptilian brain are largely unconscious and automatic, and highly resistant to change. The reptilian brain is the dominant brain when we are in the lying down position or in a human coma.

The Limbic System or Mammalian Brain

The mammalian brain was the second brain to evolve and is comprised of, among other parts, the brain stem and cerebrum. It is involved with emotions, memory formation and long-term memory; it connects events with feelings and controls hormones and temperature. For these reasons, it’s also known as the visceral or feeling brain. Like the reptilian brain, it operates primarily on a subconscious level and without a sense of time.

The limbic system, which is a set of brain structures within the mammalian brain concerned with the emotions, is active in situations that arouse fear, anger, frustration and pity. By linking emotions with behaviour, the mammalian brain serves to add a layer of control to the automatic responses of the reptilian brain.

The mammalian brain is dominant when relating to another person, animal, etc., and when we are in a quadripedic position, i.e., on “all fours”.

The neocortex

The neocortex is the outermost and most recent brain to have evolved. It makes logic, speech and writing possible. It covers the outer portion of our brain, comprising 5/6^ths of the brain’s volume. It is convoluted or crumpled looking, which increases its surface area and therefore the number of neurons that connect to the rest of the body.

The neocortex enables executive decision-making, purposeful behaviour and allows us to see ahead and plan for the future. It also has specialized areas that make sense of and process information received from our senses, i.e., touch, sight, air temperature, facial expressions, tone of voice, etc., and is responsible for voluntary movement.

The neocortex is present in all primates, but most developed in the human brain. Unlike the other two brains, it operates on a mostly conscious level, is dominant when engaged and when humans are in a standing position.

Interconnectivity

All three layers of the brain are loosely connected via an extensive network of nerves. The mammalian brain and neocortex influence each other via ongoing communication, linking emotions with thinking and with voluntary action. The unique interplay of our memories and emotions with thinking and actions is the basis for our individual personalities, for our very humanity.

Whilst we like to think of our neocortex or thinking brain as being our conscious decision maker, it is, in reality, only selectively conscious. Psychologists generally agree that at best we are only 15 percent conscious of our motivations and behaviours.

This means that even when we think we’re being rational and conscious, we’re largely being driven subconsciously by previous similar experiences and emotions.

The mammalian brain stores our emotional memories. When confronted by a situation, it “searches” its stockpile of past experiences for information on how to react. Going back to the earliest time we experienced a similar situation, it checks what the response was at the time and responds similarly. In other words, our current reaction replicates the response and emotional age of the response triggered by the earlier situation.

There are times, however, when the primary functions of the various brain levels are at odds with each other. Think of the conflict you might feel when having to make a difficult decision or when you can’t seem to prevent yourself from acting irrationally.

Here’s an example: You’ve made a conscious decision (neocortex) not to eat chocolate tonight because you know chocolate triggers a migraine if you eat it when you’re tired. Your subconscious brain (mammalian), however, thinks: “Mm-m, but chocolate tastes so goooood, I love chocolate”.  You resist, initially (neocortex), but then suddenly, you eat the chocolate anyway, justifying it by saying: “I’ll only have a little bit; I worked hard today and deserve a treat”. Bingo, the unconscious brain wins.

The combination of reptilian brain and early emotional memories stored in the mammalian brain determine our response. And when our response feels out of sync with our conscious intention, we create a rationale to support our reaction, as in the above example.

The subconscious brain is the ultimate decision maker; it always wins. In some cases, it is the unconscious reptilian brain that is concerned with our survival, “saving us from ourselves”, as it were. If it determines a situation is not good for us, it will say, “No”. In the example above, however, since the chocolate wasn’t endangering your life, the decision was deferred from the reptilian brain to the (also subconscious) mammalian brain, where the emotional memories of chocolate’s good taste and previous use as a reward were securely stored.

Can our conscious brain ever win? Understanding the different roles of our three brains—and especially the combined functions of our unconscious and subconscious brains—is important in understanding our self-sabotaging behaviours and in beginning to take control.

Recognising that our conscious, thinking, logical brain is actually only responsible for, at best, 20% of our decision making helps explain why changing behaviour or making other changes can be so challenging.

You see, for the purpose of healing old childhood wounds, the mammalian brain tries to re-create childhood responses. This repetition compulsion, as it’s called, is why we can end up repeating behaviours again and again, even when we don’t want to.

Following is a real example from my practise that illustrates how understanding the interconnectedness of our brain(s) and our behaviours can help liberate us from undesirable circles of repetition and set us on a new path to wellness.

Jane (not her real name) had been struggling for years to overcome chronic fatigue syndrome. Naturally, she was desperate to become well again. Using Neuro-Emotional Technique, we discovered, however, that subconsciously, Jane was actually not in agreement with being 100% healthy! Further questioning revealed that she also was not very good at setting personal boundaries. Remaining ill was providing her a seemingly legitimate reason to set a boundary and say “No” to demands or requests from others.

It is not uncommon to find that people with a chronic illness are not good at saying “No” to demands from others. Being ill provides the cover they need to set a boundary without the personal discomfort some feel at denying a request.

The Neuro-Emotional anti-sabotage process—and an understanding of the various brain functions at work—enabled Jane to uncover the originating event and release the beliefs that were no longer serving her. This enabled her to feel her needs were as valid as everyone else’s and that it was okay at times to deny requests from others. Once she saw how being ill had been serving her, she was able to release the emotion of the originating belief and her health improved dramatically.