The Oracle: What are some types of sleep studies conducted at Stanford?

Maurice Ohayon: We conduct laboratory studies where the participant comes to the sleep lab and spends the night sleeping in a room that looks like a regular bedroom. The difference is that we put several electrodes on different areas of the head and body to monitor what is happening during sleep. Brain waves register the different sleep stages, which allows us to verify if the individual goes through the five sleep stages: Stages I, II, III and IV that are non-REM (Rapid Eye Movements) sleep and REM sleep and if there are some anomalies such as leg and arm movements, respiration problems to verify if the individual may have a condition called sleep apnea, when the individual stops breathing for some seconds during his sleep.

We also conduct genetic studies. Some sleep disorders have a genetic component and are more likely to be found within the individuals of a same family.

And we also conduct epidemiological studies: these consist of interviewing a large number of the general population to determine the frequency of certain sleep disorders and the risk factors associated with these sleep disorders.

TO: How have sleep patterns among people changed since technology was introduced?

MO: It is generally admitted that we sleep about one hour less per night compared to people at the beginning of the 1900s. Also, some traditions–like the siesta culture–have been lost.

TO: How do you feel about lack of sleep among high school students and how it will affect their future in the long run?

MO: There are several studies that have shown a decrease in academic performances among students that are sleep deprived.

TO: What are some questions that are still unanswered about sleep to this day?

MO: The studying of sleep is still in its infancy. REM sleep was discovered less than 50 years ago, in 1959, by a French neurobiologist, Michel Jouvet.

For example, in the past five years, sleep scientists have begun to investigate the association between sleep, eating habits and neuropeptides. Why? Because sleep plays an important role in energy balance. Starvation or food deprivation results in decreased sleep, and total sleep deprivation causes marked overeating. It is therefore tempting to infer appetite and sleep share some mechanisms.

TO: Just how common are sleep disorders among people?

MO: Insomnia symptoms (difficulty falling asleep, difficulty maintaining sleep or non-restorative sleep) are found in about 30 percent of the population, excessive daytime sleepiness (feeling too sleepy during the daytime) is found in about 15 percent of the population, obstructive sleep apnea syndrome in about four percent of the population, sleep paralysis (being unable to move at sleep onset or upon awakening) in about six percent of the population and narcolepsy in about 40 per 100,000 people.