Science: Two brains are better than one

You will need both sides of your cerebrum functioning if you are to understand all of this article.

Are you a left-brain or a right-brain sort of person? Left brainers, according to one ``relationship guide'' published this summer, are "blunt, straightforward, tenacious" and so may need some help in understanding "intuitive and spontaneous" right-brainers. The book is just the latest of dozens that have exploited the popular idea of a link between personality type and the workings of our brain.

It all began 30 years ago when Scientific American magazine published an article describing what happens if you cut the connection between the two halves of the brain, so they no longer communicate with each other. Language and problem solving were found to be the job of the left side, while visual and spatial tasks were carried out by the speechless right hemisphere. Hence the popular idea that our brains housed this neurological odd couple.

But "dichotomania", as such over-simplification has been dubbed, obscures a much more interesting debate about how the left and right brains actually interact in daily life. "Far from being the silent one, lost in a creative haze," says Robert Ornstein, professor of cognitive neuroscience at Dartmouth College in New Hampshire and author of a new book on the two hemispheres, "the right brain turns out to be vital for understanding the really interesting aspects of language, like jokes, lies and metaphors."

However, one of the authors of the original Scientific American article, Professor Michael Gazzaniga, formerly of Stanford University in California, disagrees. He has written an update for the magazine, published last month, which declares that "the left brain's consciousness far surpasses that of the right".

Gazzaniga's claim is rooted in one of the most striking of the early findings - that the left brain is the ultimate story-teller. It spins yarns to explain what is going on, with absolutely no concern for the truth. For instance, Gazzaniga would write out a request, such as ``pick up that shovel'' and reveal it only to the left eye of a split-brain patient, so that the information is processed by the brain's right hemisphere (visual signals from the left eye are sent to the right side of the brain).

Then he would ask the patient: "why did you pick up that shovel?" The reply would come from the left hemisphere, the only one that can speak. Although there was no access to the real reason, because the link to the right brain was cut, the patient would give some plausible explanation about tidying up or putting it in a safe place.

Subsequent research suggests that this "interpreter mechanism", as Gazzaniga called it, may lie behind the phenomenon of false memory. If you ask a normal person about something they have seen, they will often include details that were not actually there - a well known problem for eye-witness reports. Studies of split-brain patients show that the left brain is far more likely to make these errors than the right. Brain scans have shown that when a true memory is being recalled only the right brain lights up, while both hemispheres are active during a false one.

Mostly, however, the "interpreter mechanism" is reliable. In fact, Gazzaniga believes the left hemisphere is what gives us our sense of identity. One of the brain's many extraordinary feats is taking information from hundreds of modules - for speech, for movement, for vision and so on - and integrating them into a whole, so we can say: "I did this, I saw that." Gazzaniga suggests that this could be done by the left hemisphere, endlessly trying to explain why things happen. "The inventive and interpreting left hemisphere," he concludes, "has a conscious experience very different from that of the truthful, literal right brain."

Ornstein's interpretation could not be more different. For him the right brain is the one that gives us an overall view of the world and enables us to understand where we are. He was one of the researchers involved in the debate from the beginning. It was his best-selling book, The Psychology of Consciousness, that helped to popularise the original idea of the division of labour between the two hemispheres. When he returned to the subject 30 years later, he found over 40,000 scientific papers on the subject.

Particularly revealing were a series of studies into left and right brain function using that valuable neurological research tool - the joke. "Most of the time we don't think about jokes, they are either funny or they aren't," says Ornstein. "But this research shows that understanding a joke requires some quite complex mental processing, much of which goes on in the right brain." In his new book, The Right Mind: Making Sense of the Hemispheres (Harcourt Brace), he gives an example: "A woman wants to cook a rabbit stew but the hares hanging at the butcher's are quite large, so she says to the butcher, `I'd like to make some rabbit stew but these things are too big. Could you cut one in two for me?' Then comes the punch line `Sorry ma'am, we don't split hares here'.'' Not a rip roarer but a nice little pun, a play on hare/hair. However, research by Professor Howard Gardner at Harvard University has found that patients with right brain damage do not get jokes like this.

"To understand a joke you have to be able to follow the story and try to guess at what is going to happen," Ornstein says. "You know the punch line will not be what you expected but, and this is the important part, it will fit in with the story in a surprising way. The problem that right- brain patients have is that they can't hold a situation in their mind - and then relate it to the word play that links the two."

It seems that the right brain is what we use to understand the context, which is why these patients also find it difficult to spot sarcasm. Take this situation. The boss asks a secretary to send off some letters quickly. Some hours later he finds her making a social phone call to a friend, the letters unposted. "You have been working hard," the boss says. Ask a right brain patient why he said that and you are likely to get a fantastical explanation of why he might want to praise the secretary. Here, Gazzaniga's "interpreter mechanism" is hard at work without the right brain to keep it in check.

"There's a pattern emerging from this sort of research that shows the right brain handling ambiguous, metaphorical information where you need to be able to see the broad picture," says Ornstein. "The left brain does better at activities that are sequential and precise, which is why it is used for language and fine muscular movements."

Apart from this ability to see the big picture, the right brain is also in charge of an apparently mixed bag of other functions with no obvious link, such as negative emotions, the control of large muscle groups and musical perception. But why?

Ornstein's other suggestion is that the link originates in the womb. Because the right hemisphere develops slightly faster, it gets to handle the low-frequency sounds heard inside the mother's body. Immediately after birth, it deals with the equally broad-brush visual information about the mother's face.

Other important early functions like responding to unpleasant emotions and controlling the movements of large muscles are routed to the right brain for the same reason. This early experience with the broad, fuzzy picture, Ornstein believes, could form the basis for handling ambiguous information later.

It is all a long way from the logical left and the free-spirited right. Thirty years on, the left looks more like a salesman, the right a corporate strategist, but you need both every minute of the day.

Arts and Entertainment
Tate Modern chief Chris Dercon, who will be leaving to run a Berlin theatre company
Arts and Entertainment
Tasos: 'I rarely refuse an offer to be photographed'
arts + ents
Have you tried new the Independent Digital Edition apps?
Arts and Entertainment

ebooksNow available in paperback
Arts and Entertainment

Arts and Entertainment
Arts and Entertainment
Girls on the verge of a nervous breakdown: Florence Pugh and Maisie Williams star in 'The Falling'
Arts and Entertainment
Legendary charm: Clive Owen and Keira Knightley in 2004’s ‘King Arthur’
FilmGuy Ritchie is the latest filmmaker to tackle the legend
Arts and Entertainment
Corporate affair: The sitcom has become a satire of corporate culture in general

TV review

Broadcasting House was preparing for a visit from Prince Charles spoiler alert
Arts and Entertainment
tvReview: There are some impressive performances by Claire Skinner and Lorraine Ashbourne in Inside No. 9, Nana's Party spoiler alert
Arts and Entertainment
Glastonbury's pyramid stage

Glastonbury Michael Eavis reveals final headline act 'most likely' British pair

Arts and Entertainment
Ewan McGregor looks set to play Lumiere in the Beauty and the Beast live action remake

Film Ewan McGregor joins star-studded Beauty and the Beast cast as Lumiere

Arts and Entertainment
Charlie feels the lack of food on The Island with Bear Grylls


The Island with Bear Grylls under fire after male contestants kill and eat rare crocodile
Arts and Entertainment
Aaron Taylor-Johnson as Quicksilver and Elizabeth Olsen as Scarlet Witch, in a scene from Avengers: Age Of Ultron
filmReview: A great cast with truly spectacular special effects - but is Ultron a worthy adversaries for our superheroes? spoiler alert
Arts and Entertainment
Robin Ince performing in 2006
Arts and Entertainment
Beth (played by Jo Joyner) in BBC1's Ordinary Lies
tvReview: There’s bound to be a second series, but it needs to be braver spoiler alert
Arts and Entertainment
Paul Hollywood and Mary Berry, the presenters of The Great Comic Relief Bake Off 2015

Arts and Entertainment
A still from Harold Ramis' original Groundhog Day film, released in 1993

Arts and Entertainment
Christopher Eccleston (centre) plays an ex-policeman in this cliché-riddled thriller

TV review
Arts and Entertainment
Lena Headey looks very serious as Cersei Lannister in Game of Thrones

TV This TV review contains spoilers
Arts and Entertainment

Arts and Entertainment
Wiz Khalifa performs on stage during day one of the Wireless Festival at Perry Park in Birmingham

Arts and Entertainment
Festival-goers soak up the atmosphere at Glastonbury


Arts and Entertainment
Star Wars creator George Lucas


Arts and Entertainment


  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    Robert Fisk in Abu Dhabi: The acceptable face of the Emirates

    The acceptable face of the Emirates

    Has Abu Dhabi found a way to blend petrodollars with principles, asks Robert Fisk
    Nepal earthquake: One man's desperate escape from Everest base camp after the disaster

    Escape from Everest base camp

    Nick Talbot was sitting in his tent when the tsunami of snow and rock hit. He was lucky to live, unlike his climbing partner just feet away...
    Adopting high fibre diet could dramatically cut risk of bowel cancer, says study

    What happened when 20 Americans swapped diets with 20 Africans?

    Innovative study in the US produces remarkable results
    Blake Lively and 'The Age of Adaline': Gossip Girl comes
of age

    Gossip girl comes of age

    Blake Lively is best known for playing an affluent teenager. Her role as a woman who is trapped forever at 29 is a greater challenge
    Goat cuisine: Kid meat is coming to Ocado

    Goat cuisine

    It's loved by chefs, ethical, low in fat and delicious. So, will kid meat give lamb a run for its money?
    14 best coat hooks

    Hang on: 14 best coat hooks

    Set the tone for the rest of your house with a stylish and functional coat rack in the hallway
    Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

    Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

    How a costume drama became a Sunday night staple
    Miliband promises no stamp duty for first-time buyers as he pushes Tories on housing

    Miliband promises no stamp duty for first-time buyers

    Labour leader pushes Tories on housing
    Aviation history is littered with grand failures - from the the Bristol Brabazon to Concorde - but what went wrong with the SuperJumbo?

    Aviation history is littered with grand failures

    But what went wrong with the SuperJumbo?
    Fear of Putin, Islamists and immigration is giving rise to a new generation of Soviet-style 'iron curtains' right across Europe

    Fortress Europe?

    Fear of Putin, Islamists and immigration is giving rise to a new generation of 'iron curtains'
    Never mind what you're wearing, it's what you're reclining on

    Never mind what you're wearing

    It's what you're reclining on that matters
    General Election 2015: Chuka Umunna on the benefits of immigration, humility – and his leader Ed Miliband

    Chuka Umunna: A virus of racism runs through Ukip

    The shadow business secretary on the benefits of immigration, humility – and his leader Ed Miliband
    Yemen crisis: This exotic war will soon become Europe's problem

    Yemen's exotic war will soon affect Europe

    Terrorism and boatloads of desperate migrants will be the outcome of the Saudi air campaign, says Patrick Cockburn
    Marginal Streets project aims to document voters in the run-up to the General Election

    Marginal Streets project documents voters

    Independent photographers Joseph Fox and Orlando Gili are uploading two portraits of constituents to their website for each day of the campaign
    Game of Thrones: Visit the real-life kingdom of Westeros to see where violent history ends and telly tourism begins

    The real-life kingdom of Westeros

    Is there something a little uncomfortable about Game of Thrones shooting in Northern Ireland?