A tale of two brains is more fiction than fact

 

The famous opening sentence in Charles Dickens’ 1859 novel, A Tale of Two Cities, ‘It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness …’, aptly applies to this modern tale of two brains. In this age of wisdom, many of us still believe in the foolish idea that rationality, logic and verbal skills are located in the left hemisphere of the brain, while creativity, emotions and visuospatial skills are located the right hemisphere. This assumption leads us to believe that left-brained people are logical and good at mathematics and right-brained people are artistic and bad at mathematics.

The erroneous thinking that information is processed in different ways in the two hemispheres of the brain is still reflected in our schools: the best teaching techniques for left-brained people should involve verbal instructions, talking and writing, and multiple-choice questions; while demonstrated instructions, drawing and manipulating objects, and open-ended questions are best for right-brained people. This notion has led to the idea that education programs should synchronise the two hemispheres by including both left-brained and right-brained activities. ‘Show and tell’ activities of your early school days are the result of this thinking: instead of only reading a ‘left-brained’ text, your teacher also showed pictures and graphics to stimulate your right hemisphere.

The left brain/right brain myth can be traced back to the days of 19th-century craze of phrenology (even Herman Melville made his Moby Dick narrator, Ishmael, an amateur phrenologist). Phrenologists studied shape and size of the head to determine a person’s character and mental abilities. They believed that different mental functions were located in different organs of the brain, and the growth of the various organs was related to the development of associated mental abilities. As this growth would be reflected in the shape of the skull, personality traits could be determined by reading bumps and depressions on the skull. For example, if you move your finger on the back of your neck, you will notice a bump formed by the base of your skull. This bump, according to phrenologists, defined the attachment of sexes to each other. In 1844 this mumbo jumbo became popular when a book described the two hemispheres of brain as independent parts having an independent way of thinking. The idea even found way into Robert Louis Stevenson’s famous story, The Strange Case of Dr Jekyll and Mr Hyde, published in 1886.

A myth ‘mixed up’ with sound psychological and educational work

In the 1960s the myth found its way into the modern scientific literature when American scientists Roger Sperry, Joseph Bogen and Michael Gazzaniga embarked on what are now known as split-brain studies: how the brain’s left and right hemispheres are specialised for different tasks. Their conclusion was based on the study of patients, usually, epileptic, who had undergone a surgical procedure that severed the whiter matter neural fibres that link the two hemispheres of the brain. However, in the hands of psychologists these findings took life of their own. In his 1972 best-selling book, The Psychology of Consciousness, psychologist Robert argued that we place too much emphasis on rational, left-brain thinking and not enough on intuitive, right-brain thinking. Psychologist Betty Edwards’s Drawing on the Right Side of the Brain stressed the benefits of creative, right-brain thinking. In fiction, for example, even Stieg Larsson mentions it in his 2007 novel, The Girl Who Kicked Hornets’ Nest: ‘Isn’t that part of the brain associated with numbers and mathematical capacity?’ Jonasson said. Ellis shrugged. ‘Mumbo jumbo. I have no idea what these particular grey cells are for.’

In a 2005 essay in Nature Reviews: Neuroscience, Gazzaniga says that the split-brain research has now moved from a static view of what happens in a particular hemisphere to a much more interactive view how the whole brain, interacting through white matter fibre systems, orchestrates the entire cerebral network into coherent and apparently seamless cognitive action. It amuses him that his split-brain work has now becomes such a part of popular culture.

He laments that it has become ‘mixed up’ with sound psychological and educational work that demonstrates that children use a variety of cognitive strategies to solve problems. ‘There are some kids who visualise problems and other kids who verbalise them,’ he says. ‘That reality has been mapped on left brain/right brain anatomy as an explanation. But that’s where it falls down.  Cognition, in general, is much more complex than that. That’s what we have learned over the years and continue to learn as we study hemispheric differences.’ In brief, the brain’s two hemispheres do not work independently; they work in a highly coordinated fashion.

Sophisticated brain-imaging techniques also reveal less romantic sides of the brain: there is no evidence that the left brain is ‘mathematical’ and the right brain ‘musical’. Yes, the brain is divided into two hemispheres. They look almost identical anatomically, but they are not independent. They are connected by thick bundles of nerve cells which carry information from one side to the other. The two hemispheres differ not so much in what they do, but in how they process tasks. The left hemisphere is better at details (such as recognising a particular face in a crowd), whereas the right hemisphere is better at dealing with a general sense of space (the relative positions of people in a crowd). In the case of language, for example, the left hemisphere focuses at step-by-step processes, such as grammar and word generation, whereas the right hemisphere focuses at feeling a rhythm, such as intonation and emphasis of speech.

There are no specific ‘left brain’ or ‘right brain’ cognitive functions. Both hemispheres work in concert with each other, whether we are reading, painting or solving an algebra equation. The brain is remarkably adaptive and children who have had hemispherectomy – in which half of the brain is removed – the remaining half overtakes most of the functions of the missing half. Whether you are young or old, learning actually strengthens and creates new connections between neurons.

When half a brain is better than a whole brain

Walter Dandy, an American surgeon, pioneered hemispherectomy when in 1923 he performed the procedure on a patient with brain tumour in the right hemisphere. The man lived comfortably for more than three years after the operation. In 1938 Kenneth McKenzie, a Canadian neurosurgeon, was the first to perform hemispherectomy in a case of debilitating seizures that could not be controlled by medication. The operation was success, and today hemispherectomy is a well-established procedure for the treatment of certain kinds of epilepsies in children.

In 2003 an American study confirmed the lasting benefits of hemispherectomy. The study showed that the quality of life of 111 children with chronic, severe seizures greatly improved after the procedure. There was a downside: the children had partial paralysis on the side opposite the removed portion. However, most adapted to their handicapped side so well that they could walk, run and play the piano, golf, ping-pong — some could even dance and skip.

‘When half of the brain is bad, it’s better to take it out,’ asserts Eileen Vining, an American neurologist and a co-author of the 2003 study, in the prestigious medical journal Lancet. ‘This allows the remaining hemisphere to function more normally and often regain function that was lost in the constant seizures.’ Children’s brains are plastic – they have the ability to change – and the remaining portions of the brain overtake most of the functions of the missing side.

Yes, half a brain is better than a whole brain.

In perfect harmony

It’s time we used our whole brains to learn that like Chinese Yin Yang symbols the two hemispheres of our brains are in perfect harmony. Don’t let the left brain/right brain neuromyth stereotype children’s capabilities and limitations. Individuals do have relative strengths and weaknesses but it doesn’t mean that we let Jane think that she is not good at mathematics because she is right-brained. It would be foolish to think that our strengths and weaknesses come from the dominance of one hemisphere.

There is no program or technique that can boost capabilities of your right or left brain. Similarly, no scientific study supports the claims made by ‘whole brain’ training programs. Why waste money on brain-training programs to exercise your brain, when you can exercise your brain on your own for free by learning a new language or learning to play bridge, chess or a musical instrument?

© Surendra Verma 2016

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