The average human sighs 12 times per hour; that's once every five minutes. And it's not just a sign of frustration, sadness or exasperation. The fact is that we need to sigh to make sure we're breathing properly, that's why the new generation of artificial respirators come with an added feature; an inbuilt sigh generator! Professor Jack Feldman of UCLA and his team have just identified the part of the brain that transforms a normal breath into a sigh, a discovery that could help to treat people with breathing disorders.