Research: Laughter is contagious

[13 December 2006 - Wellcome Trust] Laughter is truly contagious, and now, scientists studying how our brain responds to emotive sounds believe they understand why. Researchers at University College London (UCL) and Imperial College London have shown that positive sounds such as laughter or a triumphant "woo hoo!" trigger a response in the listener's brain. This response occurs in the area of the brain that is activated when we smile, as though preparing our facial muscles to laugh. The research, funded by the Wellcome Trust, Action Medical Research and the Barnwood House Trust, is published today in the Journal of Neuroscience. Led by Dr Sophie Scott, a Wellcome Trust Senior Research Fellow at the Institute of Cognitive Neuroscience, UCL, the research team played a series of sounds to volunteers while measuring their brain's response using an fMRI scanner. Some of the sounds were positive, such as laughter or triumph, while others were unpleasant, such as screaming or retching. All of the sounds triggered a response in the volunteer's brain in the premotor cortical region, which prepares the muscles in the face to respond accordingly, though the response was greater for positive sounds, suggesting that these were more contagious than negative sounds. The researchers believe this explains why we respond to laughter or cheering with an involuntary smile. More