Remember the old textbook picture from high school biology of the brain covered with dotted lines and labels like ‘speech’ or ‘vision’? A new school of thought in brain science is catching on, one that depicts a teeming, nebulously structured tool where microscopic actions not only dictate its form but can change it on a macroscopic scale.
The Brain That Changes Itself, a 2008 book by US psychiatrist Norman Doidge, talked about how shifting connections between neurons changes us. The science of ‘neuroplasticity’ involves the steering of experience to literally rewire the brain and cure anything from phantom limb syndrome to addictions.
University of Western Australia’s Assen Jablensky, a professor working with psychoses and neuropsychiatry, agrees the brain’s incredible capacity to restructure could have applications we wouldn’t believe. “The brain is a 1.4kg organ with about 100 billion nerve cells. This kind of interconnectivity and complexity is hard to imagine, and genes only do half the work. Growing up in a richly stimulating or an impoverished environment makes a great difference to how the brain establishes its mature ‘architecture’. Many mental health problems from depression to drug addiction are related to these two factors.”
But neuroplasticity is about more than higher mental or social functioning. If you tie two fingers together for a month, it’s said you won’t be able to move one without the other when you untie them. Your brain has been retrained to consider them co-dependent, the neural connections that tell you they’re two separate fingers long broken. “We now know some treatments can stimulate the development of new neurons from primordial stem cells in particular brain structures,” Professor Jablensky says. “‘Rewiring’ is a popular simplistic term but it still hints at the ability of the brain to regenerate structures after damage.”
We’ve even seen such self-repair in cases of serious brain trauma or — in the most extreme examples — people born with literally half a brain. According to a fixed brain model, you’d expect debilitating problems in whatever skills we associate with the brain hemisphere that’s missing or damaged. Instead, subjects often show full, albeit slow brain functioning. Even after severing the connections between brain hemispheres (a common treatment for serious epilepsy) somehow the system still works.
“There are many well-investigated cases where the brain has been able to compensate for such loss and gain some sort of normal functioning,” Professor Jablensky says. “Intact parts of the brain can take over functions of the lost parts and reconstitute the lost function.”
Another idea to emerge from the new research challenges the age-old idea of the brain at war with itself — reason fighting emotion and left-brain functions struggling against those of the right. Culturally, we tend to distrust emotion and instead use reason to drive important cultural institutions like our judicial system.
US science author Jonah Lehrer offers a new idea in his book The Decisive Moment. Instead of jostling to portray their exclusive version of the world around us, reason and emotion work beautifully together. Reason gives us our ‘big picture’ appreciation, like the ability to put off immediate gratification for a longer-term goal. Emotion gives us a short flash of focused insight, and when it mattered — such as when faced with a predator — it gave us the power of rapid response where applying objective reason to every aspect of the environment would take too long and cripple us with indecisiveness.
“It’s a question philosophers and neuroscientists have been trying to tackle for ages,” says Jablensky about how the brain makes up its mind which direction to follow. “The simple answer is, we don’t know. The not-so-simple answer is that consciousness and memory — a major prerequisite for the subjective experience that makes us a person — depend on particular brain structures and also appropriate input and learning from the social and physical environment.”
But there’s a dark side, and sometimes the short flash of insight can lead us astray without us knowing. In his book The Hidden Brain, Washington Post science writer Shankar Vedantam calls emotional response ‘speed at the expense of sophistication’. Unconscious filters can affect our judgment about a situation or person immediately and unfairly, and the distorted vision that sometimes results is responsible for a host of social ills. In one experiment, schoolchildren asked to judge photographs of faces overwhelmingly chose those of black skinned people as ‘evil’.
Even though our understanding of how our mind works is growing exponentially, medical science still confounds us at every turn. But we’re slowly grasping a new appreciation of how a billion tiny movements make us not only who we are but everything we can be. And best of all, you don’t need expensive equipment, surgery or experts in labs to perform these experiments in brain science. With every dream, memory, skill or emotion, you’re rebuilding your own brain every day.