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Switch On Your Brain - Dr Caroline Leaf

A Book Review by Koila Costello.

I chose to read and review this amazing book called “Switch on your Brain - the key to peak happiness, thinking and health” by Dr Caroline Leaf , exactly three months ago. I was thankful for the three month period because I not only got to read it but to also practice and use her 21 Day Detox plan.

On Sunday July 4, in the week that I was supposed to hand in my review, I encountered a traumatic incident. Without going into too much detail about what happened to me, the nature and effect of the incident gave me the opportunity to use this wonderful book to help with my healing process at a profoundly deeper level.

I am so thankful to be a part of this journey with the Salt Mentoring Community, because I had this additional gift and tool to use on my life when I most needed it. It further strengthens what I learnt in the Intentional Living Course (John Maxwell) as well. Let me please go on and share with you some gems of wisdom from Dr Leaf.

Dr Caroline Leaf is a communication pathologist and audiologist. A Christian who has carefully chosen Bible verses to help us link the science with what she sees as relevant verses in the Bible as she helps us to understand how our brain and mind works. Dr Caroline Leaf has spent 40 years of her life in her passion studying neuroscience and how the mind works. In her book there are eight chapters explaining how the brain works and how the mind works. She also has very detailed drawings to depict this as well.

I was interested to read her book “Switch on your Brain- the key to peak happiness, thinking and health” as I have studied and worked in the area of peacebuilding, trauma healing and counselling. We social work practitioners are required to learn about the human behavior and more recently to learn about neuroscience. I not only read this book , I decided to practice the 21 Brain Detox plan which were the last two chapters of the book. I have also read books on the Law of Attraction, Cognitive Behavioral Therapy, and Mindfulness that also discuss the importance of changing our thoughts so that they are positive.

“Our life is what our thoughts make it”. Marcus Aurelius.

Dr Leaf acknowledges that her inspiration starts and ends with God.

What is that switch?

This book is about learning how to find and activate the switch that can turn on in your brain and enable you to be happier, healthier in your mind and body. What you think with your mind, changes your brain and body. We are designed with the power to switch on our brain. Our mind is that switch.

She says “Science” is finally catching up with the Bible. It (?) is showing us proof that “God has not given us a spirit of fear ,but of power and love and of a sound mind (2 Tim. 1:7). What you are thinking every moment of every day becomes a physical reality in your brain and your body which affects your mental health and physical health. These thoughts collectively form your attitude, which is your state of mind. It’s your attitude that determines much of the quality of your life.

She says the state of mind is a real, physical , electromagnetic quantam, and chemicals flow in the brain that switches groups of genes on or off in a positive or negative direction based on your choices and subsequent reactions. This is called EPIGENETICS.

Spiritually this is the enactment of Deuteronomy 30:19.

I have set before you life and death, blessing and cursing: therefore choose life, that both you and your descendants may live”.

Epigenetics is referred to as a new science, but actually it is as an ancient science that we find throughout the bible. At its most basic level, it is the fact that your thoughts and choices impact your physical brain and body, your mental health and your spiritual development. Your choices affect not just your own spirit, soul and body but also the people with whom you have relationships.

Our thoughts , imagination and choice can change the structure and function of our brains on every level; molecular, genetic, epigenetic, cellular, structural , neurochemical and electromagnetic and even subatomic. Through our thoughts , we can be our own brain surgeons as we make choices that change the circuits in our brain. We are designed to do our own brain surgery. Choices become signals that change our brain and body and these choices are not necessarily dictated by our genes. The sins of our parents can create a predisposition, not a destiny. You are not responsible for something you are predisposed to because of an ancestral decision. You are responsible however to be aware of them, evaluate those predispositions and choose to eliminate them.

The brain responds to your mind by sending these neurological signals throughout the body, which mean that your thoughts and emotions are transformed into physiological and spiritual effects, and then the physiological experiences transform in to mental and emotional states. It’s a profound and eye opening thought to realize something like a belief, can take on a physical existence as a positive or negative change in our cells. We are in control of all of this. The choices you make today not only impacts your spirit, soul and body but can also impact the next 4 generations.

We are wired for love

The greatest news is that we are wired for love. Which means that our mental circuitry is wired for the positive and we have a natural optimism bias wired into us. Our default mode is one designed to make good choices. So our bad choices and reactions were wired in by our choices, and therefore can be wired out. Our brain is neuro plastic and it can change and regrow. In addition God, has built in the operating principle of neurogenesis - new nerve cells are birthed for our mental benefits.

This sounds like Lamentations 3:22-23”the Lords mercies ..are new every morning”.

This book shows how to get back control over your thoughts and renew (as in Romans 12:2) and rewire your brain in the direction you were originally designed to do.

Our perception of the environment plus how we manage our environment controls our bodies and lives. So if you change your perception, you change your biology. You become the master of your life instead of a victim. But you don’t do this without Christ, remember he is the vine from which we grow (John 15:5)


Neuroplasticity (the ability of the brain to change in the response to thinking) can operate for you as well as against you, because whatever you think about the most, will grow. This applies to both the positive and the negative end of the spectrum.

The ability to quiet your mind, focus your attention on the present issue, capture your thoughts and dismiss the distractions that come your way is an excellent and powerful ability that God has placed with you. In the busy age we live in, however, we have trained ourselves out of this natural and necessary skill. Natural, because it is wired into the design of the brain, allowing the brain to capture and discipline chaotic rogue thoughts, necessary, because it calms our spirits so we can tune in and listen to God.

When we are mindful of catching our thoughts in this way, we change our connection with God from uninvolved and independent too involved and dependent.

The primary success of capturing your thoughts will be to focus on God’s way first, not the world’s ways. And the science is showing that meditating on the elements of Jesus’s teaching rewires healthy new circuits in the brain. Science is able to demonstrate that we are wired for love, and fear which incorporates anything toxic, is therefore not our norm.

An undisciplined mind is filled with a continuous stream of worries, fears, and distorted perceptions that trigger degenerative processes in the mind and the body. We cannot afford not to bring all thoughts into captivity to Christ Jesus (2 Cor.10:5) we pull down every proud obstacle that is raised against the knowledge of God; we take every thought captive and make it obey Christ.

Research has shown 5 to 6 minutes a day of focused meditative capturing of thoughts shifts frontal brain states so that they are more likely to engage with the world and increases the chances of a happier outlook on life.

Multitasking is a persistent myth. What we do is shift our attention rapidly and haphazardly from task to task, resulting in two negative things 1) we don’t devote as much focused attention as we should to a specific activity task or piece of information and 2) we sacrifice the quality of our attention.

She calls this multishake multitasking. This opens us up to shallow and weak judgments and decisions, and it results in passive mindlessness.

When we distort love and truth, we wire this perversion into our brains and in a sense create brain damage. If we allow ourselves to learn fear, it creates chaos and havoc in our brains.

Choosing to be Happy!!

The book also says to achieve peak happiness through our thoughts and health, we have to remember that we CHOOSE it. The way to find this state she says is to harness the neuroplasticity. God has designed it in our brain and we can choose to rewire or renew our Mind ( Roman: 12:2). This is the lifestyle that will bring us closer in alignment to our original design or perfections (Matt: 5:48). Of being made in God’s image(Gen 1:26).

She says we can actively choose happiness, rather than letting our external and internal word of wired in and learned thoughts and our biology define happiness for us. We need to wire in positive thought networks that can fills us with power to get us back on track (2 Tim 1:7) It is the imparted word that will save our souls (James1:21). Who we are is where happiness lies, but this is so often blocked by who we have become.

To detox your thought life, you need to remember its your thinking that will actually change your brain. So you need to do consciously what your mind does on a nonconscious level to build a thought. You control your brain, it does not control you.

5 Step Switch on your Brain

The method she talks about is using the 5-step Switch on your brain learning process - based on her Geodesic Information Processing theory, which describes the science of thought. It has at its heart focused, organized and disciplined deep intellectual thinking to break down toxic thoughts and build up healthy thoughts-and in doing so, change your brain in a positive direction. When applied daily with the correct time frame, it becomes a lifestyle of thinking that renews the mind, creates real change and freedom and brings you closer to God.

In her research in the 1990s, she found the nonconscious metacognitive mind is more powerful than the conscious cognitive mind. When you engage the nonscious mind through deep thinking, you bring memories into the conscious mind in a vulnerable state, which means you can change them or reconceptualize them.

You not only add information, you have redesigned the memories and this can go in a positive or negative direction. This is called creative reconceptualization. As an individual you are capable of making mental and emotional changes in your life. Through your thinking, you can actively recreate thoughts and therefore, knowledge in your mind.

She has worked with PTSD, Brain injury patients, students with learning problems and adults wanting to pursue higher education. In South Africa, she worked with starving children who had not eaten for days or had lost parents to AIDS. When they saw Choose to change your mind, and learned it as a wonderful privilege, not a burden, they saw great opportunities.

She says you have to choose to have a controlled thought life and to be happy and healthy. Everyone can learn how to improve their thinking, learning and intelligence.

The 5 steps include:

  1. Gather

  2. Focused Reflection

  3. Write

  4. Revisit

  5. Active Research

You do the 5 steps into bringing the toxic thought into consciousness and then proceeding, over the 21 days to destroy it.

Now reading and doing the steps are two different things entirely. It required me to dig deep to be able to go through these steps.

Each of these steps has specific instructions and scripture to emphasize the points. As I went through each day for 21 days, going over each of the steps I could see the value of doing this each day and experiencing the change.

I want to encourage you to read this book if you feel that this type of information appeals to you and you want to do the hard work of creating new thoughts and new neural pathways and focusing on what God needs us to be, to be the best version of yourself.

She has chosen the following scriptures in her book as well.

  • Mathew 5:8 , you are aiming for a pure heart

  • Faith without works is dead (James 2:20)

  • Building a healthy thought and a toxic thought- you can change this using Phil 4:8. God says don’t be anxious hand it over to him in prayer and replace it with a good thought straight away.

  • We are instructed to gain wisdom, meditate on knowledge until we understand. (Philipians 4:8)

  • When you think you can change, bring into captivity every thought 2 Cor 10:5. Thoughts are constantly remodeled by renewing of your mind Rom 12:2.

  • Nothing they have imagined they can do will be impossible for them (Gen 11:6). Faith is the substance of things hoped for, the evidence of things not seen (Heb 11:1).

  • As we go though this process you will be fulfilling what God calls us to do in Romans 12:2, renewing the mind and in Mathew 5: 8 you are aiming to be going for a pure heart

On the 2nd of July a dear friend also sent this bible reflections which matched what I had been reading. I know there is no coincidence.

Satan is after your greatest asset , your mind, What you think affects everything about you and if the devil can control that , he’s got you. Proverbs 4:23 “Above all else guard your heart, for everything you do flows from it”. Your mind controls your feelings, emotions and actions. So often we pray to God to change our circumstances, but its far more important for him to change our minds because until our thoughts change, transformation won’t happen. All temptations begins in your mind for it is the battleground for sin. Minds left to run wild result in stress, fatigue, and anxiety, but a mind that is stayed on Jesus enjoys peace and tranquility.

Proverbs 7:2-3 tells us “Keep my commandments and live; guard my teachings as the apple of your eye. Tie them to your fingers; write them on the tablet of your heart”.

Mark 7:20-23;Psalm 139:23-24;Romans 12:2, 2 Corinthians 10:5. ( Brendawalsh)

The Reviews

It is so interesting to start a book that has been reviewed. I didn’t read the reviews until I had to come to write my own review. I think it was a good thing because I could then pick out the reviews that stood out for me.

“Dr Leaf demonstrates to us that these breakthroughs in neuroscience are actually ancient, already referenced in the Bible. Neuroscience is actually confirming God’s word. Carolines gift is her ability to renew our childlike wonder at God’s wisdom and creation; we are truly fearfully and wonderfully made (Psalm 139:14).

In the second part of the book Dr Leaf explains how this knowledge can be applied to our lives in a way that even a child can understand. Drawing from her years in clinical practice, she is able to give us practical steps that can truly transform our lives: spirit, soul and body. I have seen firsthand how these steps have revolutionized people’s lives in family, church, and educational settings. Indeed they have transformed their own life” Dr Peter Amua-Quarshie.MD,MPH,MS neuroscientist.

“ Dr Leaf has spoken at Gateway on many occasions, and we’re so grateful for the impact she’s had on our congregation. We’re seen firsthand how her unique and ground breaking messages changes lives. She understands that your brain is fearfully and wonderfully made by God. We encourage you to act on the wisdom found in Switch on your Brain and begin the incredible journey of thinking God’s way”. Robert and Debbie Morris, pastors of Gateway Church:authors of the Blessed Life, The Blessed Marriage and the Blessed Woman.

Written by Koila Costello

21 July 2021


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