Are we really programmed machines, functioning through circuits that we cannot change and live the life predetermined by the brain we were born with, or are we capable of reconnecting and reprogramming the mind and controlling our own lives?
Neuroscientist Hannah Critchlow wonders what the latest research on the brain tells us about our free will, what is inherited in relation to what is acquired.
The brain of an adult is not immutable
In the beginning of neuroscience, the principle that all neurons in the brain arose before birth and that it was impossible to repair a damaged brain was generally accepted. For years, neuroscientists have assumed that the structure of the adult human brain is immutable. In other words, we were only referred to what we had. But in the 1960s, that attitude began to change. New experimental research has indicated the exact opposite: there was evidence that the brain could actually be plastic, that is, that it could adapt, grow, and even regenerate.
Subsequent experiments proved that the brain retains the ability to change large-scale, in structure and function, even in the sixties, seventies and eighties. One of the most important changes is neurogenesis – the growth of new neurons from neuronal stem cells in an adult. This offers enormous potential for our ability to heal, says Sharon Begley, an American journalist and author of Plastic Brain. Therefore, treatment methods such as Cognitive Behavioral Therapy (CBT) – a form of speech therapy, can help you deal with your own problems by changing the way you think and behave.
Stimulating neuroplasticity, that is, the brain’s ability to constantly change, could help people. When we are taught to think differently about our life experiences, during this type of psychological intervention, it can actually affect both the structure and function of the brain, says Sharon. But beware of what Sharon calls neuro-hype – the belief that we can change everything about our brain, because it can hit us in the head. What happens when someone fails to overcome depression or trauma by thinking? Are we going to accuse them of not thinking the right thoughts? Sharon wonders. The idea that everything that went wrong in the brain can definitely be fixed is a step too far, says Sharon.
What plasticity means for gender roles
Biological determinism can categorize and severely limit individuals. For example, we could attribute many aspects of behavior to gender stereotypes – some people do believe that your sex chromosomes affect how you behave. Women are irrational and men unemotional? It will not be, says Gina Ripon, a cognitive neuroscientist and author of the book Gender Divided Brain. Gina questioned the idea that the brains of men and women are different and that those differences are immutable. She discovered that there is nothing in human biology that would justify the idea that there are gender differences in the brain. Instead, Gina says that people are induced to develop a male or female brain because of all the experiences they have accumulated over a lifetime that have told them that their abilities and behavior are determined by gender.
The brain is a much more active actor in the world than we were ever aware of, she says, and that is why the world and what exists in the world have a much greater impact than we could ever have imagined. The adaptability of the brain works in both directions and, according to Gina, the same idea of plasticity, which we now know lasts from birth to advanced years, could help us escape from outdated and outdated prejudices about gender and the restrictions they impose.
Plasticity and parenting
When faced with parenting decisions, it can be quite comforting to think that life is, to some extent, immutable. Inherited, unlike acquired, could help a parent cope with the pressures of life in a time of decision-making and endless parental anxiety. So, if the acquisition is so important, should parents worry more about how they raise their children? Brain plasticity could also be a source of optimism for parents, says Gina: If we don’t play Mozart to our newborn baby, she can still have music lessons as a child and even learn to play the piano as an adult. Plasticity means a more carefree and positive attitude towards human potential – a world in which children’s brains are more of an empty plate, relieved of the fate of genetic heritage.
How plastic can the brain really be?
Our brains change every day. Every time you learn something new or think of a new thought, you create and consolidate new neural connections in your brain, building a new physical structure in it.
But how much can we expect to change?
Most important changes are happening at the micro level; these are small changes in the level of synaptic connections between individual neurons, says Kevin Mitchell, a neurogeneticist at Trinity College Dublin in Ireland, where our memories are formed, for example. In his book, Innate, Kevin says that it might not be bad to constantly remind us that brain plasticity is not unlimited and to be more skeptical of the idea that at the macro level we can experience transformations that can change our personality.
We should weigh the evidence a little more carefully, Kevin says, and be distrustful of the idea that we can change anything we want, that we are free to break all the shackles of our own genetic destiny and turn ourselves into the person we want to be.
We use our brains all the time. We use the auditory and visual parts of our brain all the time, he says, and yet they are not constantly growing. If every part of the brain we use all the time became bigger, our skulls would explode at some point.
Also, what research like Kevin’s shows is that the degree to which our brain is plastic is, ironically, determined by our genes. Perhaps only a few of us were born with the right genes that provide the potential for growth in our hippocampus.