Think Again: Reinterpreting the Brain

BrainThe old picture of the human brain from textbooks with dotted lines and labels like ‘speech’ or ‘vision’ is rapidly becoming a thing of the past. US psychiatrist Norman Doidge’s book The Brain That Changes Itself portrays the brain more like the grand staircase at Hogwarts School of Wizardry, neurons constantly shifting, reconnecting and disconnecting. Each new connection is part of a skill, memory or feeling we can learn or unlearn, and Doidge argued that psychiatric treatment could encourage new ‘mind maps’, areas of neural activity we can engineer to cure everything from phantom limb syndrome to addictions.

Professor Perminder Sachdev, professor of neuropsychiatry at the University of NSW and the author of The Yipping Tiger, agrees in the principle of neuroplasticity, but reminds us the brain’s not nearly that simple. “Notions about the rigidity of the brain have been challenged in the last twenty years,” he agrees. “After a stroke there is a lot of dysfunction but it gradually improves over time. Some of that recovery is because some neurons recover, so we’ve realised there is some plasticity in the network. But after a very dense stroke people are often left with a severe deficit that’s difficult to manipulate with physiotherapy or other techniques, so there’s a constraint on how plastic the brain will be.”

Much of the treatments Doidge’s book talks about involve simple repetition, actions that generate neural networks to create a new reality. Tie two fingers together for a month, he says, and when you untie them you won’t be able to move one without the other. The mind map covering their use has been re-wired to consider them co-dependent.

Revelations about our feelings, memories or abilities is emerging across neuroscience. If you believe in an immutable sense of self — your ‘soul’ — you might be disturbed by research from Rebecca Saxe, associate professor of cognitive neuroscience at MIT. She applied a magnetic field to a brain region associated with moral judgment and changed the way subjects reacted to hypothetical moral scenarios. The manipulation of neurons had literally changed people’s ethics. If we can indeed rewire ourselves to break a habit, make a task second nature, or even aspects of our essential selves like our morals, maybe there’s no ‘self’ at all, just microscopic electrical networks reacting to the environment.

Together with neuroplasticity, research has revealed a new model of mental cohesion. We’re all familiar with the sensation of being at war with ourselves — reason fighting with emotion and left-brain functions struggling against those of the right.

Culturally, we tend to distrust emotion — the emotional rollercoaster of the menstrual cycle was once termed ‘hysteria’ and regarded as mental illness, for example. By contrast, we tend to maintain anything that’s culturally important according to reason. Our entire judicial system is based on the dispassionate attention to facts. Even Star Trek’s Mr Spock was seen as the pinnacle humanity should hope for, committed to impartial logic instead of a slave to passions like the human crew.

US science author Jonah Lehrer offers a new way to look at it in his book The Decisive Moment. Instead of jostling to portray their exclusive version of the world around us, separate functions of the mind like reason and emotion work beautifully together.

Being at work all day when it’s beautiful outside isn’t much fun, but we do it because we know our bills will fall due at the end of the month — that’s the ‘big picture’ appreciation of reason at work. Emotion gives us a short, reactive flash of tightly focused insight, and when it really 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.

But there’s a dark side. Sometimes the tightly focused insight can lead us astray from the big picture without us knowing. As Washington Post science writer Shankar Vedantam says in his book The Hidden Brain, emotional response is one of ‘speed at the expense of sophistication’. Unconscious filters about a situation or person go to work immediately, 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’.

“All of us have our biases or prejudices,” says Perminder Sachdev. “We’ve learnt them from exposure to cultural artefacts over a period of time. It’s possible to change with education and repeated counter-exposure, although it’s difficult to say whether they can be completely eliminated. Learning facilitates some neuronal connections in preference to others, and this can result in a bias of responsiveness. But the strength of these connections can be weakened.”

And whatever advanced neurological treatments we can subject ourselves to, Professor Sachdev explains the beautiful elegance of the neural mapping we do every day. “We can change our minds.”