This particular article was brought to my attention by Matt, of the great Science Blog EntirelyMadd. From The Guardian :
Scientists have identified the region of the brain that is responsible for the way people view their bodies. The parietal cortex generates the body image, and disruption of the region's normal functioning could play a role in conditions such as anorexia and body dysmorphic disorder, in which people grossly over- or underestimate their body size, researchers believe.
The researchers, led by Henrik Ehrsson, a neuroscientist at University College London, scanned volunteers' brains while carrying out an illusion that made them think their waists were shrinking.
Each of the 17 volunteers had a vibrating device attached to their wrist to stimulate a tendon, which created the false sensation that the wrist joint was flexing. When they placed their hand on any part of the body, the imaginary wrist movement made them think that part of the body was shrinking or growing.
"We found that a specific part of the parietal cortex was very active during the experiment," said Dr Ehrsson, whose study appears in the online journal Public Library of Science Biology. Volunteers who felt the strongest shrinking sensation showed the highest activity in this area of the brain. "It supports the idea that our brains compute our body size by integrating signals from the skin, muscles and joints, as well as visual cues," he said.
Other studies have shown that damage to the parietal cortex can make people feel their shape has changed.
Matt's blog has a hilarious but true article on the jargon used in scientific research papers, plus a lot of other goodies. Worth a regular visit.