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The triune brain: Crocodiles, monkeys, babies Orchestrating your baby's brain development |
Your Baby's Brain Understanding how different areas of the brain work, how cells fire and networks form, reveals that babies are born ready and needing to be in relationships. Babies are emotionally sensitive long before birth. It is also clear that emotions are a vital part of health. Emotional experience while in the womb and in infancy shape brain development, with effects lasting through life. Science shows that feeling safe and content, feeling loved and heard, and physically in touch with a loving adult (preferably mum), are keys for your baby's optimal brain development, and for health. The early years matter What your baby experiences from conception onwards influences the structure and the function of her brain as it develops in this critical early period. Your baby is nourished by nutrients that reach her via the placenta but this is only part of her nutrition. The emotional aspect of womb life is also important. Being exposed to high stress levels and fear in the womb is very different from an environment of safety and ease. The emotions that influence your baby in pregnancy - which include the feelings you have, which are relayed in many ways including via chemical messages, and her own independent emotional reactions - impact the growth and networking of her brain cells. Later in life, right into adulthood, the neural networks that formed at this early stage still have an influence out: this follows Hebb’s law that ‘cells that fire together, wire together’. Dealing with high anxiety in the earliest months in the womb, for instance, primes a person's brain to repeat the anxiety response even in situations that are only mildly stressful. In a similar way, feeling content, calm, wanted, loved and safe while in the womb, inclines a person to expect loving relationships and repeat calm and loving behaviour. Experiences after birth are similarly important. f your baby learns relationships are fun, trusting, safe and pleasurable, she’ll be inclined to seek this out in adulthood. Unwittingly, we each have a tendency to recreate the experience of our childhood, including the hugely influential period we spend in the womb, for the rest of our lives – and brain science now reveals the mechanisms behind this. Social brainOur human brains have evolved to incline us to be deeply sociable creatures. Each neurone follows a programme to develop very specifically so that it will respond to certain stimuli. For instance, certain neurones are primed to respond to the perception of eye contact and the emotional messages conveyed by facial expressions. In fact, specific clusters of cells in the brain are able to respond to a range of facial expressions. From the moment we are born we recognise fear, disgust, love or anger in others' faces. And we respond instantly and unconsciously, thanks to the way our brains form according to gentically driven form and function inherited from our distant ancestors. Cells designed to fire in response to eye contact and facial expressions, and to touch, are located within parts of the brain that assign emotional value, or categorise the experience as if it is good or bad, safe or dangerous. These parts include the amygdala and orbitofrontal cortex, both in the limbic brain centres and their pivotal role in our learning in crucial: we learn, and our brains develop, most intensely, according to the emotions we feel. We are all born with the tendency to seek proximity with a care giver. Seeking eye contact is an in-born tendency of the brain, as active as the urge to seek out the nipple, and is active at birth. From the moment we take our first breath we are compelled, driven, to invite our parents to bond and dance with us. In a similar way, specific cells drive us to explore our environment, in search of discovery and novelty. The experiences we gain from exploring, and from being in contact with our parents, encourage new growth of brain cells (neurogenesis) and the creation of new neural networks. Each one of us forms unique network patterns in our brains: it is these networks that allow us to learn, and to remember the people in our family and wider social group. Our triune brain: Crocodiles, mammals and humansThe human brain has evolved over eons. Scientists refer to the ‘triune’ brain since it has three main areas, each one a product of evolution. Crocodile ‘reptilian’ brain At the core of our brain is the most ancient, ‘reptilian brain’, a network of specalised nerve cells and brain matter that arose when the first reptiles evolved hundreds of millions of years ago. The way this functions remains largely unchanged since ancient times. It’s in charge of survival – controlling essential bodily functions including hunger, circulation, heartbeat, temperature, breathing, balance, movement and digestion. It also gives us territorial instincts, drives us to mate, and is the source of our fight-or-flight reflex. Reptiles do not have emotions and feelings. The ‘reptilian’ brain may equip us with basic survival instincts, but it does not offer us a capacity for love, nor does it instil the urge to bond or to protect other family members. A baby crocodile, for instance, may one day be snapped up by the father crocodile or another predator and the mother will feel nothing. This is in stark contrast to elephants, who are known to grieve when a family memeber dies. Why are they different? Elephants have a mammalian brain. Mammalian ‘limbic’ brain In evolutionary terms, the next stage in brain development is the arrival of the ‘mammalian brain’. This happened 100 million years ago. This limbic brain or emotional brain furnishes all mammals with a wide range of emotions and feelings that influence every thought and action, every second of our lives. Having a limbic brain is integral to forming and staying in relationships – something that’s certainly to our evolutionary advantage. Without a limbic brain, we would be bereft of the capacity to love and feel loved, and the gift of emotions. The limbic brain has a huge influence on other parts of the brain; it is involved in every brain process. The limbic brain, and the emotions and feelings it gives rise to, are more influential in every thought and action than the more recently evolved thinking brain. Thinking ‘rational’ brain The latest phase in the evolutionary development of the brain comes with the neocortex, or ‘rational’ brain. It’s also known as the higher brain or the frontal lobes. It allows us to think, talk and discuss our ideas, and to recognise our feelings. The size of the neocortex in humans far exceeds that of other mammals, setting us apart in our ability to reason, communicate and speculate. It is central to understanding maths and physics and intellectual concepts. The cells of your baby’s neocortex are all present at birth, but it does not begin to function fully until towards the age of two. Before this time, your baby is driven by her mammalian brain, and interprets her world according to the way she feels emotionally. Her early experiences are not remembered consciously, through the neocortex, but are not lost - they are retained in her 'implicit' memory, which informs her perception and choices throughout life. Orchestrating your baby's brain development How you parent your baby affects the way the three parts of her brain function. Ideally, they will function well together, and she will grow with an appropriate response to fear and danger, an ability to love and behave with compassion, and the skill to recognise and respond to her feelings and the feelings in other people. However, all of us are most vulnerable and open in our earliest years from conception on, when brain development is at its most intense. The way we are nurtured by our parents either promotes or undermines balanced development. For instance, when a child feels a lot of emotional pain the potential for neural networking in the brain that allows rational thoughts to link with feelings is cut short. A child with such experience is likely to become over-rational and find it difficult to form friendships and to trust. A child who repeatedly feels afraid draws excessively on the reptilian brain systems, following primitive impulses of defence and attack that are not mediated by the limbic brain, nor tempered by rational thought. The neural networking in your child’s brain is partly and minimally decided in her genes before birth: but it depends more heavily on the experiences she has in her relationship with you and the other people and events in her life, in pregnancy and beyond. Babiesknow shows you how to give your child the start that she deserves. Hard Wiring and Hebb’s Law Cells that fire together, wire together. So goes the catchy phrase that very well sums up how our brains learn in response to experience. Initially suggested by psychologist Donald Hebb not long after the close of World War II, this theory suggests that the more often certain cells fire together, the more likely they are to fire together again in the future. There is no actual wire network – as each event in the brain is an interchange of electrical impulses and chemical exchanges between cells – but cells do learn and they do always operate as a community. Hebb’s theory applies as much to learning to talk and walk as it does to learning to love and feel loved. In every part of the brain, from the reptilian area that helps us regulate hunger, satiation and digestion, to the limbic brain that helps us express and mediate anger, and to the neo-cortex which enables us to remember names, telephone numbers and complex theories, ‘hard-wiring’ is at work. Every human has a huge number of neurones. As babies, we are born with many billions. While some are genetically geared to fire together and wire with one another from birth (like cells enabling us to see and favour faces above all other visual stimuli) by far the majority will only fire together when they learn how to do so, according to experience. Cells that are not called into use actually atrophy and die: this follows a principle of ‘use it or lose it’. By the age of three, your baby will have formed billions of networks and will also have lost millions of unused brain cells. Each experience encourages:
Emotional attraction – limbic resonanceLimbic resonance is unconscious. Each one of us resonates with the person or people around us, and our moods are literally infectious. The process involves signals picked up unconsciously, including facial expression, tone of voice, body movements and the wordless messages passed through eye contact. Limbic resonance with you is one of the most important factors in your baby's life. Your love, acceptance and willingness to be there, your honesty, care and playfulness, will all contribute to harmonious resonance and optimal development of your baby's limbic brain. There's no doubt now that babies need loving carers if they are to develop well. Experiments have been carried out with monkeys who fail to thrive if separated from their mum. More tragic experiments involving human babies have also been conducted, with disastrous results. Although society's pressure is to follow reason above our hearts, and to achieve rather than to attach, neuroscience is showing very clearly that listening to our limbic signals - our feelings - and to celebrate them in our babies, is a valuable source of fun, loving and guidance through life. back to topLearning to love The mechanisms that encourage some cells to fire together, and others to be pruned, mean that for each individual baby a completely unique brain map evolves. Both structure and function are influenced by your baby’s experience. Once this is in place, although the brain always retains an element of flexibility, a norm has been established and established neural networks tend to be followed. Experience wires the brain, and then the nature of what it has experienced actually determines what it can experience. What this means for your baby, on an emotional level, is that the lessons she learns about emotional feelings and how love feels in close relationships will be applied by her brain through life. Within the networking of her brain, emotional attractors form – so without ever intending it to happen, she will attract similar relationships, triggering similar feelings, as she goes through life. The relationship she has with you – her first meaningful relationship – in this way offers a kind of blueprint and will be repeated. The message is very simple: children who feel loved and safe in the womb and in their earliest relationships after birth, and feel encouraged to express themselves, set out on a positive path involving significant brain development that enables them to experience more relationships like this. Here is the golden opportunity for parents - to do their best to make this possibility a reality. All contents copyright © Babiesknow, 2008. All rights reserved. |
"A child is born with the hardware for limbic sensing, but to use it skilfully he needs a guide … someone must teach him how to sense the emotional world correctly.’
'Everything a person is and everything he knows resides in the tangled thicket of his intertwined neurons. These fateful, tiny bridges number in the quadrillions, but they spring from just two sources: DNA and daily life. The genetic code calls some synapses into being, while experience engenders and modifies others.’ |
