It has been estimated that the human brain contains something in the region of eighty-six billion neurons. Ironically, the human brain struggles to make sense of numbers of that magnitude. To demonstrate this, pause for a second to estimate how long it would take to count to eighty-six billion saying one number every second. What did you come up with? A month? A year? A hundred years? In fact, it would take a little over 2727 years to count from one to eighty-six billion.
Neurons are the basic building-blocks of the brain and wider central nervous system. Everything we think, feel and do is a result of neurons sending and receiving electrical and chemical signals, between different areas of the brain as well as between the brain and the rest of our bodies. The neurons in our brains connect to form incredibly complex neural networks. Imagine something like a roadmap of Great Britain, though with trillions more roads. (There are fewer than eight-hundred thousand roads in Britain and in the region of one hundred trillion neural connections in our brains!)
Some neural pathways are well-travelled and, as such, become strengthened over time. These are the motorways of our neural networks – familiar, much frequented, sometimes infuriating. Such neural pathways may be associated with learning a skill, but equally they might be associated with particular ways of thinking or feeling that become established (though perhaps entrenched might be a better word for some of our ways of thinking or feeling) as we return to them again and again.
Educational neuroscience, as the name suggests, applies what we know about how the brain works to education. Of particular interest to educationalists is understanding the way in which we store and later retrieve information in the form of both knowledge and skills. Neuroscientists have identified three distinct stages of memory development. The first stage, encoding, involves converting sensory perceptions into meaningful representations in the brain. This is followed by consolidation, in which those representations are strengthened by making connections with past experiences and other knowledge already stored in our memory. Finally, retrieval involves recalling and applying memories when needed.
Learning then is essentially the process by which information is encoded, consolidated and retrieved. These processes physically change the brain by creating, reinforcing and reorganising neural networks. The roadmap in our brains then is not fixed but forever changing. Like Kipling’s road through the woods, some neural networks are lost to time, ‘disappearing underneath the coppice and heath / And the thin anemones.’ Other routes become well-trodden and familiar, turning B-roads into A-roads and A-roads into motorways, whilst elsewhere short-cuts are found, or entirely new roads are cut through the neural landscape.
Though neural pathways are strengthened through practice and repetition, one of the lessons that neuroscience teaches us is that massed practice, that is, doing the same thing over and over again, is one of the least effective learning strategies. Deeper, more durable, learning requires teaching to focus on conceptual knowledge rather than factual or procedural knowledge. It is very easy for someone to say that you need to put a full stop at the end of a sentence, but for a child to put that into practice they must first understand what a sentence is. And the concept of what we mean by a sentence is incredibly complex. We arrive at a conceptual understanding of what a sentence is by reading lots of sentences. Lots and lots of sentences. More importantly, we spend hours and hours picking sentences apart, and at least as many hours putting sentences together, all under the watchful eye of a knowledgeable and dedicated teacher. Over time, our brains make sense of where a sentence comes to an end and where, therefore, to put a full stop.
To give another example, a generation ago when we were at school, we would have been taught to work out a multiplication such as 18 x 5 using a column method with one number written underneath the other. In contrast, a mastery approach to teaching and learning Maths develops children’s conceptual knowledge by encouraging them to explore different methods. So to work out 18 x 5, you might start by working out 20 x 5 before subtracting 2 x 5; or you might break up the 18 in different ways, to give 10 x 5 and 8 x 5 perhaps, or 9 x 5 and 9 x 5; alternatively, you might recognise that 18 x 5 gives the same result as 9 x 10. Returning to our roadmap metaphor, consider a London taxi driver who has to navigate the capital’s congested thoroughfares on a daily basis. Learning just a column method for multiplying 18 x 5 is like learning a single route from, say, Waterloo Station to Westminster. A London taxi driver wouldn’t ever learn just a single route, of course; instead, they would be familiar with several interconnected routes, giving them multiple options. If we learn only one way of multiplying 18 by 5, there is the risk that our knowledge of that approach will quickly fade; but if that learning sits within an interconnected network of neural pathways, that is, if our learning is joined with other areas of learning within a bigger conceptual framework, then it will be much more durable.
Neuroscientists use the word neuroplasticity to describe the brain’s ability to continue to adapt and evolve in response to everything that life throws at us. It is an incredibly powerful idea, as is eloquently summarised in Make it Stick: The Science of Successful Learning: ‘This single fact – that our intellectual abilities are not fixed from birth but are, to a considerable degree, ours to shape – is a resounding answer to the nagging voice that too often asks us “Why bother?” We make the effort because the effort itself extends the boundaries of our abilities. What we do shapes who we become and what we’re capable of doing. The more we do, the more we can do.’