Triune Brain Evolution: One Piece of the Dyslexia Riddle


Over 40 years ago, Paul MacLean from the National Institute of Mental Health outlined triune brain evolution, which means we have three brains that developed in a specific order. Each brain has its own functions, and if the brains do not develop correctly and in the proper sequence, learning disabilities can result.

Teaching about the three brains is often the first step I take when offering dyslexia help to parents. It helps them understand where their children’s development may have faltered, and it gives them a small glimpse into why their children may act in certain ways.BFHC-logo

Reptilian Brain
Also known as the primitive brain, basic brain or hindbrain, the reptilian brain develops first, from conception through about 15 months of life. It is the primitive part of our brain—it handles instincts and safety. If the reptilian brain senses danger, it causes us to fight, flee, or freeze. It’s all about survival.

As the reptilian brain develops, so does the body’s vestibular system. This relatively unknown body system connects our senses with our brain. It also governs balance and orientation in space and time. When the reptilian brain develops correctly and in a timely manner, we learn to crawl and then to walk. When parents brag that their children barely crawled before walking, it’s not something to be proud of. Developing brains need the body to crawl for longer than a few days.

If the reptilian brain doesn’t feel safe, no learning takes place. This is where many children with dyslexia and ADHD have problems. That basic brain needs safety above everything else. If you’re constantly fleeing, fighting, or freezing, you can’t let new information into your brain.

Limbic System
Commonly known as the emotional brain or the mammalian brain, the limbic system develops after the reptilian brain, from 15 months to approximately four or five years. This brain is concerned with bonding, attachment, and emotions.

During the development of the emotional brain, we learn how wonderful it is to belong to a group and care for others. We discover how to motivate ourselves and how to be social during this time. All the emotions, from ecstasy to extreme sadness, are part of the mammalian brain. The ability to nurture develops at this time also.

If this brain doesn’t develop correctly, we don’t have the emotional ability to care about anyone, including ourselves. And we certainly don’t care about learning or bettering ourselves, even when our mothers cry and ask us how they can help.

You may know this one as the cerebral cortex or thinking brain. It’s the last one to develop in humans from the ages of four or five to adulthood (at least 21 years of age). Animals have only the limbic system and the hindbrain. The neocortex distinguishes us from animals by the ability to speak and form conceptual thoughts.

The neocortex is also the most complicated of the three brains. It is comprised of two halves, the left and right hemispheres. Each hemisphere has several parts, including the temporal, parietal, and occipital lobes, as well as the prefrontal cortex. The thinking brain needs a connection between the two hemispheres, which is the corpus collosum.

If this brain doesn’t develop correctly, learning is disrupted. Speaking and creating original thoughts may be delayed. Abstract thinking is halted, and this is when dyslexia becomes apparent.

Knowing how triune brain evolution works helps you realize there’s an issue with your child. Books Neural Therapy™ can help a child (or adult) whose brain developed in a different way. We can help those neural pathways develop—just call to get started. Dyslexia help for parents is just a phone call away.


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