Forced smile

Neurology journal Brain had a wide-ranging review of the book ‘Insomnia: A Cultural History’ last year which has this wonderful part about Darwin, Duchenne and how he electrocuted the face to study emotional expression.

In the same era and acting on the same beliefs, many experiments were done to study the effect of electricity on sleep and on the nervous system. Beard and Rockwell (1871) claimed that the tendency to insomnia could be removed by electricity, thus galvanizing and causing contraction of the cerebral circulation, and Charles Darwin illustrated his book on the expression of the emotions with many illustrations taken from Duchenne’s work (Darwin, 1904) [see image]. However, some of Darwin’s conclusions, such as that terror and grief were accompanied by automatic contraction of the forehead muscles, may not have been entirely justified by the apparent results since Duchenne’s subjects were admitted to be actors (Duchenne, 1871).

Duchenne was a doctor who studied the link between nerves, electrical activity and muscles. He’s probably best known in medicine for his work on what is now called ‘Duchenne muscular dystrophy‘, a muscle wasting disease caused by inherited problems with muscle protein.

However, his work on the link between facial muscles and emotions, partly researched by electrically stimulating muscles to see what expressions could be created, was groundbreaking and Darwin included Duchenne’s pictures in his book The Expression of the Emotions in Man and Animals.

Even now, psychologists talk of the ‘Duchenne smile‘ which involves raising the corners of the mouth and, crucially, raising the cheeks and wrinkling the eyes through the use of the orbicularis oculi muscle.

A ‘Duchenne smile’ is often regarded as the most genuine display of spontaneous joy or happiness, due to the fact that parts of the orbicularis oculi muscle cannot be controlled voluntarily and so this specific type of smile can’t be easily faked.

Sadly the whole review of the book ‘Insomnia: A Cultural History’ is locked, which is a pity as it works equally well as an article on its own and covers some fantastic ground.

The book itself look fascinating, and I note that the Wall Street Journal made the whole of Chapter 6 available online which is well worth a read in itself.

Link to locked review for ‘Insomnia: A Cultural History’.
Link to more info about the book.
Link to Chapter 6 at the WSJ.