Experience: the invisible sculptor of brains

With around 86 billion neurons, that dynamically connect forming neural pathways that  become highways or byways of the mind depending on their use; the brain is the most complex structure in the universe. Given that it is an insipid fawn colour, has the texture of soft blancmange, and only weighs about 1.4 kg it’s hard to imagine how it earns such an accolade. Yet years of evolution have honed our brains not to perfection, but to an extraordinary degree of flexibility, and in the decade of the brain we are making some breathtaking discoveries about the elegant and intricate biological mechanisms that serve our survival by allowing us to adapt to our very personal and subjectively experienced environment.

Experience shapes brains in more ways than we think and this has profound implications for the way we understand ourselves, how we understand and respond to criminal behaviour and what sense we make of mental health and illness. One obvious way that experience shapes brains is the way we acquire language. We learn to speak, think, read and write in the language and vernacular, complete with cultural and familial colloquialisms, and the accent and tone that we hear from the mouths around us. The same is is true, although less obviously, for the emotional and relational language of attachment and bonding. Broadly speaking, as infants, our safety and therefore chances of survival are increased by maintaining proximity to our caregivers, who are bigger, stronger and more competent in the environment than we are. Our caregivers have a particular attitude towards their own vulnerability and independence and ascribe a value and probably some judgement to these aspects of themselves, which will subconsciously and consciously get communicated to their infant through their interactions. The infant’s brain is a master pattern detector and is biologically driven to maintain proximity to their caregiver, and so the infant will learn to display more or less vulnerability or independence, depending on which garners more of the caregiver’s approval and is most successful at maintaining the infant in a close proximity to her/him. These adaptive strategies for maintaining proximity are the attachment patterns described by Mary Ainsworth in the 1960s.

But how are these nuanced emotional experiences held in the wet matter of the brain? Physical, neurobiological changes occur in the brain as a result of experience and this is neuroplasticity, the capacity of our brains to remember what is needed, to forget what isn’t, and to adapt to circumstance. Experience leads to changes on our DNA, to changes in the rate we produce new neurons, and the success with which they integrate into the existing network. These mechanisms that translate lived experience into biology are epigenetics and neurogenesis respectively. Experience builds new connections in the brain, ‘neurons that fire together, wire together’ and the repeated traffic down particular neural pathways generates myelin which makes the traffic down that route faster and more efficient. These mechanisms are synaptic and white matter plasticity. All of these processes underlie forms of learning, which occurs at a cellular, genetic and non-conscious level right up through to what is consciously learned, such as a new short cut, and what is rehearsed so very many times that it becomes almost automatic, such as learning to play our favourite piece of music.

Neuroplasticity is exciting, it offers optimism, supporting our hopes for growth and change, but knowing that experience profoundly shapes the brain brings a depth of understanding that reveals some unsettling implications and demands both our compassion and our full attention. Adults who have had experiences of abuse and neglect in childhood are over-represented in both the psychiatric and the prison populations. If those experiences of abuse and neglect in childhood make actual neurobiological changes to our brain that shape how we respond, then at what point are we responsible? At what point do we have choice and how much choice do we have? What could this mean for our ‘justice system’? Equally, we think of illness as something inside a person that isn’t working as it should, but if the environment has led to neurobiological changes occurring in the brain then what does it mean when we identify the pathology in the person and not the environment? The brain is the organ of adaptation. It adapts to a supportive or benign environment and it adapts to an adverse environment. A healthy brain is a brain that can adapt to the environment it encounters. Regarding one adaptation as ‘healthy’ and the other adaptation as ‘illness’ suggests an error in our thinking, we are ascribing different values to the exact same process. What makes the adaptations desirable in the healthy person and undesirable in the person we label as ill, is not the process of adaptation itself or anything necessarily intrinsic to the person but is a feature of the environment they have adapted to. We are locating the problem in the wrong place and our solutions follow suit. Neuroplasticity may demand its own paradigm, a shift away from the dichotomy of health and illness to a model where distress and difficulty are compassionately and richly understood to be adaptations to environments that could not support all of our needs. If our brains adapt to experience and this leads to changes that whilst adaptive are not desirable, can we choose new experiences that will generate new adaptations that are desirable? Do we need to choose and seek out healing experiences with intention and wisdom?

Experience leads to adaptive changes in the brain that we are only beginning to understand the biological mechanisms for and that as a society we will be confronted by. What I hope to do with this blog is explore the neuroscience, the philosophical implications and the meaning I find for myself in all aspects of neuroplasticity. By way of a rudely late introduction, I’m a philosopher, neuroscientist, mental health nurse and psychotherapist in training. I also have a story of complex trauma and self-harm, and through nimble manoeuvring earlier in my life, have avoided psychiatric diagnosis and intervention which would now be superfluous. From this rich, unusual and candid perspective I’m excited to bring you evidence that I find, and questions that occur to me so you can engage with what neuroplasticity means to you in your life and work.