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How Many Brains Do We Actually Have?

Written by: Elizabeth Noske, Executive Contributor

Executive Contributors at Brainz Magazine are handpicked and invited to contribute because of their knowledge and valuable insight within their area of expertise.


The obvious answer is “one” but let’s go down the less obvious route. In the 1960s American physician and neuroscientist, Paul McLean proposed his Triune Brain model. Rick Snyder reminds us that neuroscientists now acknowledge our body’s three brains: our cephalic (head) brain, our cardiac (heart) brain and our enteric (gut) brain. One of my favorite parenting authors, Dan Seigel, uses an upstairs brain and downstairs brain model to explain children’s feelings, thoughts, and behaviors and to guide parents to an appropriate response to their child. I find there is a place for all these models when coaching and informing parents, but the concepts apply equally well to leadership and understanding change.

The Triune Brain

Let’s start by examining the concept of the triune brain, which MacLean identified as the neocortex or neo-mammalian brain, the limbic or paleo-mammalian system and the reptilian brain. He proposed that each of the three brains he identified represents a distinct evolutionary stage, each forming on the older layers before it. While he acknowledged that each of these three brains is connected by neural pathways to the other two, they continue to operate as an independent system with distinct capabilities. Very few current day neuroscientists would agree with MacLean, who, to be fair, did not have the access to electron microscopy in order to map the complexity of the brain’s neural activity.

‘Connectomics’ is the study of a connectome, which is a complete visual map of the brain’s neural connections. These images clearly demonstrate both the magnitude and the dispersion of neural connections and messaging across all sub-systems of the brain. And across hemispheres, by the way, clearly debunking the left brain and right brain theory, which was based on the work of Roger Sperry, back in the 1970s. Although each hemisphere does have some distinct areas of specialization, they communicate and cooperate extensively through the axon-rich corpus callosum.

In MacLean’s triune brain model, the reptilian brain, which comprises the brain stem and the cerebellum, is a very old structure that shares primitive behaviors and responses with snakes and lizards. He describes it as being rigid, obsessive, compulsive, ritualistic, and paranoid. The concept appeals to coaches and therapists seeking to explain the fight-flight-freeze aspects of human behavior. The limbic (mammalian) brain was believed to be concerned with emotion, attention, and emotional memories. The physiological structures include the hypothalamus, hippocampus, and amygdala. The neocortex, or Neomammalian brain was referred to by MacLean as “the mother of invention and the father of abstract thought”. The prefrontal cortex is the crown in the cerebral jewel.

Dr Sarah McKay wrote in 2002 that “most neuroscientists no longer support the notion that our lives are ruled by hard-wired instincts deployed automatically in response to particular triggers with certain emotions… This so-called ‘classical view’ of emotions is falling out of favour as we learn more about how the brain works, and more about how humans learn and even more about consciousness”. Nevertheless, presented as a concept rather than a physiological description, I find that the triune brain model does have the advantage of simplifying neural anatomy so as to be user-friendly to the complete novice. When referring to it, I always warn parents that it isn’t supported by current neuroscience research, but it can help the why’s and wherefores of children’s behavior.

How This Theory Relates to Parenting

Mindful parenting is about being present and aware in the present moment. In the ABCs of parenting, the Antecedent is the past; whatever has happened up until this very moment. The Behavior is the present; the actions you and your child are taking right now. The Consequence is the future; what is likely to happen in the immediate and the long-term future as a result of the behavior that has just taken place.

Our past hurts, triggers and habits are mostly below our conscious awareness, often as deep as our reptilian brain. There is nothing rational or logical about actions that erupt from this part of our brain when it feels threatened or unsafe. When we rely on our Neomammalian brain we are assuming that rational thought and logic are the best gifts we can give our child. Well yes…and no. If we attempt to teach with logic, before we have connected with and soothed their emotional limbic brain, we are wasting our words, our energy, and our teaching points. So, calm the reactive reptilian brain, connect with the emotional limbic brain, and then teach them what they need to know when their Neomammalian brain has had a chance to come back on board.

Three-brain Theory

And now on to the three-brain theory, which is supported by both anatomy and neuroscience. The concept has been entrenched in our language for eons, but more recently we have the data to support it. “Heart ache, heart break, I know in my heart…” are just some of the phrases we are all familiar with. “Gut reaction, I feel it in my gut, my stomach is churning…” are also phrases commonly used that don’t actually address the digestive role of our gut. The passport to credibility for this theory is the verifiable presence of neurons, which Wikipedia describes as “an electrically excitable cell that communicates with other cells via specialized connection called synapses”. Not visible to the naked eye unless clumped together in a ganglion cluster, they are clearly and indisputably visible under the microscope.

Sensory and motor neurons abound in the spinal cord, while the brain itself has a probably 100 different kinds of specialty neurons. Each messenger neuron is supported by at least 10 glial neurons that provide structure, nutrition, and waste disposal. The previous estimate was 100 billion in the average brain, but more recent estimates come in at closer to 86 billion. Either way, I think we can all agree it’s quite a lot, especially all squeezed into a 3-pound mass that would fit inside a baseball cap.

Our cephalic (head) brain is inevitably what we refer to when we say, ‘our brain’. The majority of our neurons (the tiny electro-chemical messengers that run the show) reside here. Previous estimates of 100 billion (I often wonder who it is that does the counting) have been more recently reduced to 86 billion. Does the exact number really matter? Probably not – it’s a mighty lot, however you look at it. Our cephalic brain is an intricate, complex, but not yet well understood system of systems. We have a system for every imaginably human activity; not that we’re born with them, but rather they develop, mature, change and adapt as we consistently add to our life experiences. We have a system for survival, for reward, creativity, language, cognition, self-regulation, motivation, habits, intuition…the list is endless. The triune brain and upstairs and downstairs brain models are associated with our cephalic brain.

There are only about 40,000 neurons (called sensory neurites) in out cardiac (heart) brain, but they are incredibly powerful because they can operate independently of our cephalic brain. But they are also closely in sync with the neurons in our cephalic brain, particularly when our emotions are involved. Research indicates that both extreme anger and intense grief will affect our heart. In fact, we are 21 more times likely to have a heart attack the day after losing a loved one that at any other time. When we claim that our ‘heart is broken’ or that it ‘feels heavy’ this is not a metaphor, but an actual physical fact.

Our enteric (gut) brain has between 100-300 million neurons. This is more than either the spinal cord or our peripheral nervous system. While their primary role is to manage and control our digestion, with this number of neurons, our enteric nervous system also enables us to “feel” the inner world our out gut. Recent studies show a strong connection between our enteric nervous system and our central nervous system. Altered intestinal flora has been linked to mental illnesses, such as depression, as we as some neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases. A timely warning to pay close attention to our gut health.

How This Theory Relates to Parenting

We feel intense emotions in our heart; great joy, overwhelming grief and intense rage are likely to elicit a physical reaction in our heart. Listen to its wisdom, take note of what it is telling you and don’t just try to ‘talk it down’ from the perspective of your more knowledgeable cephalic brain. Teach your child to also listen to their heart; both messages of love and messages of fear are telling us something that we need to know. Wise parents also respect the wisdom of their enteric brain; this is where our gut instincts, emotional feelings and reactions and early warning system resides. This is not to say we can blindly trust all our gut reactions, but an intuitive parent will pause to take note of what our ‘additional’ brains might be trying to tell us.

Upstairs and Downstairs Brain Model

This excellent model is the brainchild of Dan Seigel and Tina Bryson Payne. In this model, our downstairs brain is like the ground floor of a two-story house, which is the first part to be built and it’s where we conduct our everyday activities; cooking, eating, socializing. Similarly, our downstairs brain takes care of our basic survival functions, our impulses, and our emotions. In order to survive, our early ancestors learned to minimize threats and maximize opportunities. They were very vigilant and reacted quickly and strongly if they felt at all threatened. Our downstairs brain plays the same role that it has for many thousands of years. It’s the first part of a newborn’s brain to start maturing and we can expect children, right through to adolescence and beyond to prioritize their need for Protection, Participation and Pleasure.

Just like your downstairs brain, your upstairs brain is not an actual anatomical place; it’s a concept. But it’s a great one for understanding some of the brain’s basic processes. It includes areas of the brain called the neocortex, and especially our high-performance prefrontal cortex. It’s where we conduct our more conscious and sophisticated mental processes, such as planning and decision-making. But it is also home to our self-awareness, self-control, empathy, and morality. It’s the home base for our brain’s drive for Prediction and Purpose. Are you beginning to see why toddlers don’t go there very often yet?

How This Model Relates to Parenting

You might spend your day in your home office, working through your professional tasks and activities, but at some point, you will want to come downstairs to eat, interact with your family and relax and have some fun. It’s all about balance, folks. But if you have some parenting habits you would like to change, you will have to start in your upstairs brain; reflecting on what you are already doing, visualizing how you want it to be and making plans to get there. These are all upstairs brain activities. If you don’t parent consciously and mindfully, you will slip back into your downstairs brain, which is where our dysfunctional Family Dances take place. More about the Family Dance another time.

For me the Golden Rule for parents is to CONNECT through their downstairs brain and COACH to their upstairs brain. The rule-of-thumb is to be clear, not just about which ‘brain’ is leading your child’s actions, but where your own thoughts and emotions are residing at the time. Trying to teach (which is what discipline is) while in the grip of your own downstairs brain is not going to give you the outcome you are wanting. Calm it down, if you are not already feeling calm, peaceful, and loving, before you reach out to your child.


Models and theories are useful for getting our heads around facts, concepts and processes that would otherwise be impossibly difficult and complex for us to understand. But as Bill Harris would say, they’re just the map – not the actual territory. So, appreciate their simplicity, but at the same time understand the limits that this simplicity imposes on the most amazing, dynamic and yet-to-be-understood physical phenomena that we carry around inside out skull. The human brain(s).

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Elizabeth Noske, Executive Contributor Brainz Magazine

Elizabeth is a unique parenting coach because she:

  • Made all the mistakes you could possible make as a young mother

  • Finally got her act together and went skydiving, hiking, travelled, SCUBA dived and played team sports with her children during their middle childhood and teenage years

  • Has formally studied the neuroscience of teaching, learning and parenting and is passionate about sharing her knowledge, expertise and insights with as many people as she possibly can

  • Believes that our brain has a mind of its own

  • And the only behavior we can actually change is our own

If you’d like to learn more, schedule a zoom meeting, email at, book a call on Schedule Once, visit her website, or join her on the Facebook Page Mindfull Parenting | Facebook. Her first book Mindfull Parent: Parenting With the Brain in Mind, is an easy to read neuro parenting book and her Mindfull Parent Turnaround Programs will support you through a process of changing your parenting habits.



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