Facial Expressions Reveal Sleep Quality

Science has now found that certain facial changes such as red eyes, puffy face and bags under the eyes mean that the person hasn't slept well.

The study was conducted by researchers at the Stockholm University in Stockholm, Sweden, and was based on viewers' assessment of 20 photographs. Study results showed that faces of sleep-deprived people looked sadder than others. These people also had paler skin, swollen eyes, droopy corners around the mouth and even wrinkles.

For the study, researchers photographed ten participants twice; once when they had a good eight-hour sleep and second when they hadn't slept for 31 hours.

Forty participants were then asked to rate 20 photographs for signs of facial clues of fatigue and sadness.

According to researchers, the face can reveal vital details about a person's personality such as competence and aggressiveness.

Human brain devotes a large section to understand what other people are thinking. Early humans used facial signals to identify potential threats in the environment.

Recent studies have shown that people can even recognize facial expressions in dogs. Interestingly, even dogs are capable of recognizing expressions of not only their human companions, but also of strangers.

"Since faces contain a lot of information on which humans base their interactions with each other, how fatigued a person appears may affect how others behave toward them. This is relevant not only for private social interactions, but also official ones such as with health care professionals and in public safety," said Tina Sundelin, MSc, from the department of psychology at Stockholm University in Stockholm, Sweden and lead author of the study.

The study is published in the journal Sleep.

Lack of quality sleep can lead to various conditions like stroke and cancer. Previous research published in the journal Obesity reported that short sleep duration was found to be independently associated with weight gain among all age groups. Another study published in American Journal of Epidemiology too links reduced sleep with modest weight gain in women.