Sleep

Sleep becomes an object of observation

At the University of Chicago, Nathaniel Kleitman opened a laboratory devoted to sleep in 1925. With Eugene Aserinsky, he reported in 1953 the discovery of paradoxical sleep, characterized in particular by rapid eye movements. The night's recording reveals a state organized in phases, with activity that evolves instead of a simple shutdown of the brain.

Beauty sleep becomes an experience

The idea that a good night is visible on the face was then tested with photographs. An experiment published in 2010 compared the same people after normal sleep and after sleep deprivation. Observers judge sleep-deprived faces to be more tired, less healthy and less attractive: a common intuition becomes a measurable result.

In 2017, another experiment used two nights of restricted sleep in twenty-five participants, then had their photographs evaluated by one hundred and twenty-two observers. Perceived attractiveness drops again. This work gives sleep a concrete place among habits linked to appearance, with effects evaluated on the face rather than only on the fatigue felt.