[he] leaps across boundaries,
making unexpected connections,
juggling a dozen trains of thought at once"
This quotation by Oliver Sacks, the renowned neurologist who inspired my fascination with the three-pound organ situated in, and protected by, the cranium, figuratively describes how the connections, in the order of trillions, made between our billions of neurons control every aspect of our existence. I was born with a squint in my left eye, wearing a patch as a young child over my right one. The treatment worked because of changes to the neural connections of my left eye, rectifying the squint, because of the restrictions to those controlling the right. This example of the brain’s plasticity, a concept posited by William James in 1890 to describe the brain’s malleability and later coined in 1948 by Jerzy Kornorski, a neuropsychologist and student of Pavlov, in terms of functional transformations of neurons, is described by David Eagleman, a prominent contemporary neuroscientist and author, as the livewiring of the brain, which is a dynamic, high-connected and competitive process.
The first time I ever heard of neuroplasticity was when I joined in 1995 the fifth cohort of secondary-school science practitioners to be trained at King’s College, London, in the two-year programme that developed teachers’ classroom practice with Cognitive Acceleration through Science Education (CASE). The brain’s plasticity was mentioned during our professional development sessions in relation to the theoretical underpinnings of the intervention approach, including how cognitive activities in CASE lessons promote changes in the brain’s neural networks. Whilst Piaget’s qualitative model of cognitive development, in particular equilibration, has remained a bedrock of CASE (which has evolved into a number of Let’s Think programmes), animal studies were mentioned by Michael Shayer and Philip Adey, the co-founders of CASE, as empirical evidence to support their conjecture regarding a relationship between neuroplasticity and the methodology’s cognitive activities, in particular Green and Greenlough’s (1986); this study’s results showed that rats living in a more cognitively stimulating environment had an increase in neural connections compared with the control group by the analysis of their hippocampal slices in vitro. `
As someone new to the profession, I quickly became a proponent of social constructivism, with a keen interest in neuroscience, in particular how children’s cognitive development can be accelerated by presenting them with stimuli that are somewhat surprising; this is a central tenet of the CASE classroom methodology, described as cognitive conflict. In Eagleman’s book, The Brain, he states that when we are born, the human brain is ‘remarkably unfinished’, ready to make the neural networks that allow us to develop into conscious, adaptable individuals. This is in contrast to other mammals where offspring can walk and feed themselves moments after their birth; this initial advantage, however, makes them less adaptable as their brains have already been largely hardwired. The assumption made by cognitive psychologists, as part of the branch of psychology that emerged in the 1960s, that the brain’s high level of functioning can partly be explained by it developing internal representations of the external world, has resonated with me throughout my career as a science teacher and CASE practitioner. Meta-analysis of educational research supports students experiencing challenges as a key component of effective learning and cognitive development. I believe that these somewhat surprising stimuli create challenges because at times they are not compatible with our internal representations of the external world, often exposing misconceptions; this is why they generate a buzz of excitement in the classroom, a characteristic of Let’s Think lessons, as students share their initial responses to the challenge with their peers.
Our understanding of the brain, in particular mental operations, has been transformed during the second half of the twentieth century partly by the reductionist approach of molecular biology researching the biochemical pathways, including gene expression, that lead to anatomical changes between neurons; this has provided irrefutable evidence for neuroplasticity. It is an excellent example of the nature of scientific inquiry in terms of falsifying hypotheses, allowing those that withstand this scrutiny to become the evidence base for future research. I have found the advancements in our understanding of the teenage brain over the last twenty years fascinating, especially synaptic pruning, another example of neuroplasticity; the neurological changes of teenagers provide possible explanations for the markedly different behaviours of adolescents compared with children or adults, including some who show a greater propensity for risk taking and sensation seeking in particular when with their peers.
The application of Sacks’ quotation to neuroplasticity is that our interactions with the environment are fundamental to learning and development with an interplay of conscious and unconscious thoughts as well as the establishment of both implicit and explicit memories. Whilst the reductionist approach has provided evidence that has led to numerous applications, including treatment of neurological and psychological disorders and even the technique that treated my left eye, a consistent conclusion throughout neuroscience and psychology is the importance of individual differences; we explore our environments with our own agility, developing a unique landscape of neural connections that defines who we are. As educators I believe we provide our students with a wealth of learning experiences and opportunities, both in and out of the classroom and, whatever the potential barriers may be even when facing adversity, the overwhelming message of neuroplasticity is the adaptability of, and potential in, all our students, which should know no boundaries.
Dr Martina Lecky is Executive Headteacher, Vanguard Learning Trust, UK