In 1959, Peter Tripp, a disc jockey, decided to go without sleep for 200 hours so that he could raise money for the March Of Dimes. After he spent about five days going without sleep, he began to have hallucinations. Several of the hallucinations that he had was that he believed that a tweed suit someone was wearing was made of worms, and that a drawer nearby had flames coming out of it. He did manage to get through his broadcast during the day, but felt that he was in much danger at night. After he reached the 200 hours of going without sleep, he slept a total of 13 hours and felt a whole lot better. After that he got a few nights of extended sleep, then was essentially back to feeling normal, except that he reported various feelings of depression for several months afterwards.

In 1964, Randy Gardner, a high school senior who was 17 years old at the time, tried to establish a new world record of going for 260 hours without sleep as a project for his science fair. After about the fourth day he became extremely irritable yet he retained many of his basic skills. After sleep loss of 230 hours he was still able to hold his own pinball machine with a sleep researcher from the Sleep Disorder Center at Stanford university.

Several experiments at laboratories that have involved sleep deprivation for long periods of time have found that a person's mood will first deteriorate as joy completely disappears and the person becomes very grim and very sleepy. After several days, most people start to have tiny minisleeps, which are little lapses of attention when the brain goes to sleep for only 5 to 10 seconds but then wakes up immediately afterwards. By about the fifth day, these minisleeps become longer and much more numerous. By the 10th and 11 day, the minisleeps happens so often and are so mixed with wakefulness that the subject can't tell whether they are awake or sleep. You will talk, and in the metal of having a conversation you'll have two or three different waves of sleep. You can walk, and for one step to the next you might catch a second of sleep.

During this type of sleep deprivation if you're given a task to do, such as adding a column of numbers, the minisleeps may occur without you even being aware that they are happening. However, if you're given a quick paced task (for example, if someone calls out different numbers to you that you have to add) you will probably make very many mistakes, because for the few seconds that you have a minisleep you don't hear the numbers.

These are just a few of the different types of attempts to understand sleep deprivation. The main thing that sleep researchers have discovered is that, in sleep deprivation such as losing a few hours of sleep a night doesn't really have much of an affect on a person. However if you go for several days or several weeks with sleep loss it can have an affect on your ability to function on a day to day basis.