There have been several studies of sleep deprivation. In 1959, Peter Tripp, who worked at a US radio station, went without sleep for 200 hours or 8.33 days to raise money for charity. After five days without sleep he had hallucinations and began to see things. He reported seeing flames pouring out from a drawer and worms crawling all over the doctor's coat He continued to do his broadcast in the daytime, but at night he was forced to stay awake. Eventually, after 200 hours, he stopped the ordeal and went to sleep. As he had not been sleeping for over eight days, he was expected to sleep for at least a couple of days, but though free to sleep for as long as he wanted, he slept continuously for only 13 hours, then woke up and felt refreshed He was back to himself after that, although he felt depressed for a few months afterwards. Another well-known case was that of Randy Gardner. In 1964, as a 17 year old student, he decided to break a record of 260 hours without sleep for his science project He stayed awake with the help of his friends, engaging in mental and physical activities. He did not take any drugs or stimulants. He felt extremely tired, his eyelids were heavy and burning, but he did not have any hallucinations. He managed to break the record, and stayed awake for a total of 264 hours or 11 days. He appeared to be quite well, even up to the last minute of the ordeal, and thought that he would be able to continue to do without sleep for a longer period if he wanted to. After a sleep deprivation of 264 hours, he fell asleep once he was in bed. Again, he was free to sleep as much as he wanted, but he slept a straight 15 hours only. This sleep was monitored in the sleep laboratory of the San Diego Naval Hospital. After waking up, he felt well and had no after-effects.
In Edinburgh, Ian Oswald reported in 1966 the case of six medical students who went into sleep deprivation for 108 hours or 4.5 days. When the experiment was terminated, and they finally went to sleep, they slept for an average of 12 to 14 hours straight.
The above studies appear to contradict what we normally estimate as the amount of sleep required. If we normally sleep 7 hours each 24 hours, then Tripp who did not sleep for 8.33 days would need 58.31 hours sleep to catch up; Gardner who did not sleep for 11 days would need 7 7.00 hours to recuperate; and the Oswald's students who did not sleep for 4.5 days would need 31.50 hours sleep.
Does this imply that we need only a minimum of two to three hours sleep each day, and the rest of the time that we spend sleeping is a waste or a luxury? Of course not; we must remember that
during sleep deprivation these subjects were not functioning well. Tripp was hallucinating, Gardner had heavy and tired eyes, and Oswald's students were not enjoying the experience one bit. Hence two to three hours sleep each day is not sufficient for normal healthy functioning.
However, we can draw a few important conclusions from the above sleep deprivation reports.
* After a few sleepless nights, we do not need the same number of hours sleep that we had missed out on to recuperate. A few hours more than the normal sleep period is sufficient to feel refreshed and well again. In other words, we do not need to pay back the sleep debt we create with an equal amount of sleep.
* The duration of the sleep deprivation is not directly proportional to the number of hours spent in sleep after the ordeal. In fact, in all three reports about 13 to 15 hours was required, although Gardner had been awake twice as long as the students.
* Even when these volunteers were extremely sleepy, they could not stay asleep for more than 15 hours. There appears to be a limit to how long we can continuously sleep without waking up. Is there a waking centre in the brain?
Momentary sleep whilst the person is apparently still awake is called 'microsleep'. Microsleep lasts for just a few seconds, but is very refreshing.
Microsleep occurs in less fit people, especially in the elderly. Physical activities tend to reduce the frequency of microsleep. It is well known that when we are older we need less sleep; most elderly people sleep only a few hours each day. Because the elderly have fewer physical activities in the day and are less fit, they lapse into microsleep very frequently during the day. It has been postulated that this is one of the reasons why the elderly do not require that much sleep at night. From the above, we see that the minimum number of hours of sleep can be as little as two hours a day for a short period. We also know that there are no reports of death from insomnia, although there are millions of reports of people who have died from an overdose of the drugs that treat insomnia. So why panic when you cannot sleep for a few hours at night?