THE old textbook diagram of the human brain with dotted lines and labels like ''speech'' or ''vision'' is becoming obsolete.
The 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.
Doidge argues that psychiatric treatment could encourage new ''mind maps'' - areas of neural activity we can engineer to cure everything from phantom limb syndrome to addiction.
Perminder Sachdev, professor of neuropsychiatry at the University of NSW and author of The Yipping Tiger and Other Tales from the Neuropsychiatric Clinic, agrees with the principle of neuroplasticity, but reminds us the brain is not nearly that simple.
"Notions about the rigidity of the brain have been challenged in the last 20 years," he says. "After a stroke there is a lot of dysfunction but it gradually improves … 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."
Many of the treatments mentioned in Doidge's book 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 rewired 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 alter aspects of our essential selves - such as 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 are 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 but maintain anything that is culturally important according to reason. Our entire judicial system is based on the dispassionate attention to facts. Star Trek's Mr Spock was seen as the pinnacle humanity should hope for, committed to impartial logic instead of being a slave to passions like the human crew.
The US science author Jonah Lehrer offers a new way to look at this 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 is not fun, but we do it because we know our bills need to be paid - 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 matters - such as when faced with a predator - it gives 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 is a dark side. Sometimes the tightly focused insight can lead us astray from the big picture without us knowing.
As the 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 who were asked to judge photographs of faces overwhelmingly chose those of black-skinned people as ''evil''.
''All of us have our biases or prejudices,'' says 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 … But the strength of these connections can be weakened.''
And whatever advanced neurological treatments we can subject ourselves to, Sachdev explains the beautiful elegance of the neural mapping we do every day. ''We can change our minds.''