Science: Serendipity The secrets of mirth control

LAST YEAR, the scientific journal Nature reported the story of a 16-year-old girl, known only as AK, who suffered from severe epileptic seizures. She was to undergo surgery to remove the small section of her brain responsible for triggering the seizures, but prior to the operation it was necessary to carry out a detailed survey of her brain. This was a precautionary procedure aimed at checking that the operation would not remove or damage any important brain tissue.

The survey required the team of surgeons, led by Itzhak Fried from UCLA Medical School, to apply an electrical current to 85 specific sites on AK's brain. Suddenly, when Professor Fried stimulated one particular set of sites contained within an area the size of a postage stamp, the girl began to smile. He had inadvertently discovered a part of the brain that somehow controls smiling. It is situated in the left superior frontal gyrus, which is more or less at the top of the head. If Fried increased the current, the smile turned into a giggle, and if he increased it further, the giggle turned into raucous laughter.

Fried's discovery has significant implications for our understanding of laughter. First, smiling is only quantitatively, and not qualitatively, different from laughter. Turning the smile into a laugh did not require stimulation at a different site, it merely required more electricity. Second, if we think of the laughter mechanism as consisting of three distinct stages (seeing something funny, feeling happy, physically laughing), then this particular part of the brain supplies the second and third stages. When the brain was stimulated, the patient reported a sense of glee as well as physically laughing.

To find out about the missing first stage, Fried asked AK what was making her laugh each time he stimulated her brain. On each occasion, AK reported that whatever she happened to see was hysterically funny. In other words, the electrode caused mirth and laughter, and her brain had then associated this general sense of merriment with the object that was in her field of view. If she happened to be looking at the wall, then the wall was hilarious, and if she happened to be looking at the surgeons, then they were hilarious. She commented, "You guys are just so funny, standing around like that."

Unfortunately, it is difficult to pursue this research, because surgeons cannot meddle with a person's brain merely to explore its mirth module. One potential avenue of research, however, would be to conduct experiments using non-invasive techniques such as MRI, which is capable of creating as many as four brain images per second, enough to glimpse the brain in action. Hence, it might be possible to tell a knock-knock joke to a patient, and then watch bits of the brain come to life as the joke is digested.

Suggested Topics
Arts and Entertainment

Will Poulter will play the shape-shifting monsterfilm
Arts and Entertainment

books
Arts and Entertainment
Paul Hollywood

'Whether he left is almost immaterial'TV
Arts and Entertainment

game of thrones reviewWarning: spoilers

Arts and Entertainment
The original Star Wars trio of Harrison Ford, Carrie Fisher and Mark Hamill

George Osborne confirms Star Wars 8 will film at Pinewood Studios in time for 4 May

film

Have you tried new the Independent Digital Edition apps?
Arts and Entertainment

ebooksNow available in paperback
Arts and Entertainment

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

ES Rentals

    Independent Dating
    and  

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

    Fishing for votes with Nigel Farage: The Ukip leader shows how he can work an audience as he casts his line to the disaffected of Grimsby

    Fishing is on Nigel Farage's mind

    Ukip leader casts a line to the disaffected
    Who is bombing whom in the Middle East? It's amazing they don't all hit each other

    Who is bombing whom in the Middle East?

    Robert Fisk untangles the countries and factions
    China's influence on fashion: At the top of the game both creatively and commercially

    China's influence on fashion

    At the top of the game both creatively and commercially
    Lord O’Donnell: Former cabinet secretary on the election and life away from the levers of power

    The man known as GOD has a reputation for getting the job done

    Lord O'Donnell's three principles of rule
    Rainbow shades: It's all bright on the night

    Rainbow shades

    It's all bright on the night
    'It was first time I had ever tasted chocolate. I kept a piece, and when Amsterdam was liberated, I gave it to the first Allied soldier I saw'

    Bread from heaven

    Dutch survivors thank RAF for World War II drop that saved millions
    Britain will be 'run for the wealthy and powerful' if Tories retain power - Labour

    How 'the Axe' helped Labour

    UK will be 'run for the wealthy and powerful' if Tories retain power
    Rare and exclusive video shows the horrific price paid by activists for challenging the rule of jihadist extremists in Syria

    The price to be paid for challenging the rule of extremists

    A revolution now 'consuming its own children'
    Welcome to the world of Megagames

    Welcome to the world of Megagames

    300 players take part in Watch the Skies! board game in London
    'Nymphomaniac' actress reveals what it was really like to star in one of the most explicit films ever

    Charlotte Gainsbourg on 'Nymphomaniac'

    Starring in one of the most explicit films ever
    Robert Fisk in Abu Dhabi: The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers

    Robert Fisk in Abu Dhabi

    The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers
    Vince Cable interview: Charging fees for employment tribunals was 'a very bad move'

    Vince Cable exclusive interview

    Charging fees for employment tribunals was 'a very bad move'
    Iwan Rheon interview: Game of Thrones star returns to his Welsh roots to record debut album

    Iwan Rheon is returning to his Welsh roots

    Rheon is best known for his role as the Bastard of Bolton. It's gruelling playing a sadistic torturer, he tells Craig McLean, but it hasn't stopped him recording an album of Welsh psychedelia
    Morne Hardenberg interview: Cameraman for BBC's upcoming show Shark on filming the ocean's most dangerous predator

    It's time for my close-up

    Meet the man who films great whites for a living
    Increasing numbers of homeless people in America keep their mobile phones on the streets

    Homeless people keep mobile phones

    A homeless person with a smartphone is a common sight in the US. And that's creating a network where the 'hobo' community can share information - and fight stigma - like never before