Brain development

Research (Abbott & Burkitt, 2015) indicates that the brain goes on developing throughout life, that ‘intelligence’ is not fixed but also that the early years are when the brain develops fastest. For this reason, in this guide, there is an emphasis on providing a wide range of activities for the child to stimulate the development of their brain including their ability to communicate and problem solve, to form relationships and to be resilient as well as to develop ‘fine motor skills’ ie the ability to use fingers to pick up, hold and manipulate objects and their ‘gross motor’ skills ie large muscle development. This information is of vital importance and means that if those caring for children can provide a wide range of positive experiences, the child is in a good position to move to formal education. These experiences do not require expenditure, rather they require carers/parents to introduce the child to the world around them through conversation, play with diverse objects available locally and through songs, rhymes and physical activity.

Annex : extract from the training given to leaders of parent/carer and child sessions by Baby College UK

Overview

Week 11 – Brain Development

A baby is born with a brain that is hardwired but this is just for survival, i.e. respiration, digestion and excretion. By about the 28th week in utero the nervous system is mature enough to support life. During the 29th-38th week interconnections between each individual nerve cell (neurones) develop rapidly.

The brain develops from the inside outwards. The outer layer, the cortex develops last. This is the part of the brain that makes us human. This is the “thinking brain”. At seven months’ gestation neurones begin to develop branches known as dendrites. Each neurone is connected to another at points called synapses. They continue to develop rapidly during the first few years after birth, particularly in the first two years.

How does this work?

Let us assume that a baby experiences a nasty smell. A message is sent from his nose to his brain via the olfactory nerve. In the brain the message is picked up by the dendrites and the message is directed to the cell body in the olfactory part of the brain. Here the cell body can do many things: it can store the message; share it with other brain cells; and react to the message. The cell body sends a message, via the axon, back to the nerves and muscles of the face, telling the nose to pull away from the smell and telling the mouth to stay shut. As the sensation has been stored away, the next time the baby smells that smell he will move away quickly, and with conviction ─ he has learnt an important sensory lesson.

Three Levels of Brain

In 1979 MacLean described the brain as being divided into three levels. Each represented an evolutionary stage. The first stage is the brain our ancestors had when they first crawled out of the seas and evolved into the amphibians and reptiles on the planet. The evolutional second stage was when they became mammals and began to give birth to live babies and suckle them. We became warm-blooded and started to live in social groups. The third stage was when our ancestors began to stand on their hind legs and develop our front legs as tools. Our developing brain allowed our primitive forefathers to think and solve problems

The 1st Level ─ Reptilian Brain.  The first level is the one that is functioning when we are born: it can be compared with that of the reptiles. In fact, in the first few weeks of life, the baby even makes reptilian-like movements. When a baby is born only two areas of the brain are fully developed. The first part is the brain stem, which consists of the medulla oblongata and the pons. Linked to it is the reticular formation ─ this is the brain’s alarm centre and is responsible for maintaining consciousness and arousal. This part of the brain is found in the lower area of the skull, and deals with the basic needs of life, breathing, heart rate, body temperature, suckling and the muscle tone.

The 2nd Level ─ Mammalian Brain MacLean designated the second level of the brain as the mammalian brain and is called the midbrain. It is at this stage that the baby goes through the many movement stages. These are, in order: rolling, crawling, sitting, creeping and pulling up to standing. The midbrain is the link between the brainstem and the thinking part of the brain, the cortex. It is made up of the pons, the basal ganglia, the cerebellum, and the thalamus and hypothalamus (these last two form the limbic system).

It is from the limbic system that all our emotions and our instincts originate (fear, anger, love). The hypothalamus controls the hormones involved in temperature control, hunger and water balance as well as those involved in sexual activities. The basal ganglion is responsible for the organisation of activity, which begins as involuntary, but with repetition and practice over a number of months and years, become automatic e.g. learning to sit up, to walk, to ride a bike, drive a car, play the guitar or learning to swim etc..

The cerebellum controls our movement. It acts as a filter and directs information from the vestibular nuclei, the muscles, the eyes and all our other muscles. It is therefore ultimately responsible for our body’s balance, and our reaction to gravity. The vestibular is the centre of our balance system. The organs of balance are known as the semicircular canals, and are found in the inner ear and are controlled and are directly linked with the vestibular nuclei: it is this system that much of our work in BABY COLLEGE® is concentrated on (the maturity of this system is fundamental to our wellbeing).

The semicircular canals are found in the ears and are filled with liquid containing small particles. When these particles move around too fast, they stimulate sensors in the walls of the canals, which in turn pass the message along the vestibular nerve to the brain. Messages will then be sent back down allowing us to alter our balance. This is the proprioceptive system. It allows us to know where our body is in space, how to move without falling over, and cope with gravity. We can feel our proprioceptive system working when we spin round and when we stop close our eyes. We feel our body fighting to keep us upright.

The 3rd Level ─ Human Brain.  The third level is the human or cortical brain. It allows us to be able to stand and move independently, to use our hands and learn to assimilate information and memories, and eventually learn to organise and act upon them. Eventually we become the rational, logical and linguistic animals called homosapiens.

The cerebral cortex is made up of two hemispheres, which are linked together by the corpus callosum. The right hemisphere is responsible for the sensing and control of movement on the left hand side of the body and the left hemisphere controls the senses and movement on the right. The corpus callosum acts as a telephone exchange allowing information from both sides of the brain to be analysed and acted upon. An example is the fact that the brain might see an object with right eye and name it using the left brain.

The cortex (the grey convoluted structure we recognise as a brain) is the least developed. It is responsible for finer body movement, perception, and thinking and language ─ it is the intellectual part.

Left Hemisphere

Right Hemisphere.

Speech/Verbal Logic/Maths Sequential Intellectual Analytical Perception of Significant Order: cat (word), 6 (number) & symbols

Spatial skills/Music Holistic Simultaneous Intuitive/Creative Gestalt

Perception of Abstract Pattern: cat (image), 123 (pattern) & the whole

The different roles played by the left and right hemispheres of the brain

What the Left Brain Does Best

What the Right Brain Does Best

Explains with words

Remembers using language Step by step thinking Controls emotions Takes life seriously Works with facts Analyses

Logical reasoning

Abstract tasks

Structured activities Organisation

Explaining visually

Remembers using images Holistic thinking Expresses emotions Approaches life playfully Works with pictures Synthesises

Intuitive understanding Practical tasks

Fluid open tasks

Improvisation

What the left and right brain do best

A Baby’s Brain Development

When a baby is born the neurones are all present in the brain, but not many neurones in the cortex are connected. Over the first two to three years of life the majority of the brain’s growth occurs. The number and density of dendrites and the nerve synapses increase rapidly. At about two it appears that there is some sort of pruning where the synapses that the brain deems as surplus are eliminated (it is a waste of resources to have 40 pathways to allow the child to pick up a chip from a plate and put it into his mouth. One pathway is all that is needed). However, if a stroke affects the particular area of the brain that is responsible for fine motor skills that pathway has been wiped out. A lot of hard work and repetition will be needed to establish that skill again. The old adage “use it or lose it” is also proof of such pruning in later life. Interestingly the corpus callosum is made up of 40 percent more dendrites in females than males. Perhaps this is why men can be so single-minded while the female appears to be able to multi-task with ease.

At the same time as these dendrite and synapses are multiplying, the important process of myelination proceeds. This is the development of sheaths of myelin which insulate nerve fibres rather like the plastic cover of an electric cable. This “cable covering” allows the electrical message to travel along the neuro-pathways efficiently. At birth the spinal cord is not fully myeliate and this is one of the reasons why the baby has little or no control over the lower trunk and limbs.

It is thought that physical movement stimulates the production of the myelin sheath by up to 50 percent. We can see this working when there has been physical injury to the brain and an intensive course of rehabilitation and physiotherapy is carried out. This is also one reason why “patterning” in brain-damaged children is known to be so successful. Patterning is an intensive movement programme devised to help children who are brain- damaged at birth and was pioneered by the Institute for Human Achievement in Philadelphia. It involves large numbers of helpers moving the individual limbs and head of the child in specific movement patterns over many hours a day, every day of the week. The aim is to allow the child to eventually walk unaided and lead something like a normal life.

Dendrite sprouting, through physical movement, can happen at any age. This is why rehabilitation after strokes or brain injury is so important. Sometimes, skills can be relearned, by finding another neurological route. When multiple sclerosis attacks the body, it destroys the myelin sheath and as a result, motor control is lost.

Learning New Skills and Independence

The cortex stores all our human characteristics and handles all the finer motor skills we learn. Once a skill is learnt it is finely tuned and applied to particular situations. The baby gradually builds up a memory of the five senses. It’s a bit of a hit and miss process to start with but gradually with practise all the skills become integrated.

Sounds are heard and practised. Certain sounds are used as expressions and the perceptive mum will recognise the hungry sounds, the uncomfortable sound, and the grunting sounds (of a nappy being filled). The more astute the child, the more use he will make of these vocalizations. These sounds are the building blocks for speech. By the time the baby is a year old he can recognise people, pets, familiar objects and situations. He will know what to do with familiar objects such as his bottle or his hair brush. He will be able to distinguish between the tones of voices i.e. the disapproving voice “No!” and the approving voice “Yes!”

Simple thinking, logic and problem solving are beginning to develop. This is the process by which the baby begins to become the independent human being. Every day there is something new to be learnt and enjoyed and life is one long adventure.

Growth and Pruning

At birth there are 100 billion brain cells: these expand and connect creating intricate pathways for the transmission of information. By the time a child is three there are 1000 trillion connections. From then on a pruning system is at work in which some connections are discarded and others strengthened: infancy and pre-school experiences have been proved, by scientists, to control this process.

Some US scientists also say that there are windows of opportunity – miss them and the connection is lost (e.g. the optimum time to start learning a second language is four years old). A study by the University of Chicago’s Benjamin Bloom concluded that by four most of the IQ is in place and that “general intelligence appears to develop as much from conception to age four as it does during the 14 years from four to 18.”

US research has provoked much interest and some controversy. One of the most heavily publicised reports was from research carried out by the Carnegie Corporation of New York in 1994. Called Starting Points, it stimulated discussion among educators, parents and even government policy- makers during the rest of the 90s and into 2000. The report concludes that a child’s performance at school and even his success as an adult depends greatly on experiences before the age of three.

Brain development

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Brain development

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