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Doctors discover 'laughter spot' in the human brain LONDON (February 12, 1998 00:30 a.m. EST http://www.nando.net) - A team of American doctors may have discovered a portion of the human brain which causes laughter, according to the latest edition of Britain's science magazine Nature on Thursday. Tests found that when a teenage girl was stimulated gently with an electric current in a sensitive part of her brain, in the left frontal lobe, she was seized with laughter. The 16-year-old girl was being tested with electrodes by doctors from the University of California at Los Angeles, investigating the source of her chronic epileptic seizures. During the examination, she was asked to perform a variety of tasks, including naming objects, reading, counting and extending her forearms. The doctors discovered a small area that "consistently produced laughter" when stimulated. Writing in Nature, Itzhak Fried and colleagues said: "The laughter was accompanied by a sensation of merriment or mirth. "Although it was evoked by stimulation on several trials, a different explanation for it was offered by the patient each time, attributing the laughter to whatever external stimulus was present." The girl saw a picture of a horse as hilarious, giggled over what she was reading, and laughed at the researchers present in the room, exclaiming: "You guys are just so funny." The duration and intensity of laughter increased with the level of current applied. At low levels she only managed a smile, while higher currents triggered a contagious outburst of merriment. The laughter response was not connected with the girl's epilepsy, said the doctors. They pointed out that the "laughter zone" was at the front of a larger region of the brain called the Supplementary Motor Area (SMA) which is known to show increased activity in people who stutter. The SMA is associated with the motor operation of limbs, facial muscles and speech. The doctors suggested it may also be concerned with specialized functions of speech, laughter and manual dexterity. Copyright 1998 Nando.net Copyright 1998 Agence France-Presse janet paterson 50-9 / sinemet-selegiline-prozac almonte-ontario-canada / [log in to unmask]