Scientists deprived a group of study participants of different amounts of sleep. Some got a full night's sleep, others got their hours of sleep cut down and some got no sleep whatsoever. After a while, the slightly-deprived people were as bad offas the people who had gotten no sleep. The difference was, they didn't know it. Researchers at Washington State University gave a group of study participants a relatively easy assignment. They were to sleep certain amounts of time, and then come in, fill out surveys and do a few psychological tests. During the testing, the psychologists found unusual equivalences — one being that going with only six hours of sleep for two weeks was no better than going for two days with zero sleep. The researchers published their work in the journal Sleep.
Forty-eight people participated in the two-week-long testing process. While some got long, luxurious nights of eight hours sleep, others got four, or six hours sleep. A last group participated in a truncated three-day experiment, during which they had no sleep whatsoever. Over the course of the experiment, the researchers measured the participants response time, took a look at their brain wave patterns, had them fill out questionnaires about how well they felt, and probably put up with a great deal of grumpiness.
The stand-out result of the survey was the fact that a little lost sleep every night can have major effects. According to the researchers, "chronic restriction of sleep to 6 hours or less per night produced cognitive performance deficits equivalent to up to 2 nights of total sleep deprivation". Miss out on two hours of sleep per night, and at the end of two weeks you might as well have stayed awake for 48 hours.
Things got more sinister when the researchers took a look at the participants' questionnaires. Although, after two weeks, the participants who got six hours of sleep per night took a huge hit in terms of their test results, the "subjects were largely unaware of these increasing cognitive deficits". While staggering around like someone who had been up for two days, the six-hours-per-nighters thought they were doing just fine on the tests. Loss of sleep affects us more than we know.
And it may effect us in more ways than one. Another study, published today in Genetics, showed that a specific protein, VAV-1, helped nematode worms "sleep" after they were stressed. After being heated to 40C, the worms that could produce the protein slept, and the ones that couldn't produce the protein didn't. The ones that didn't sleep were much more likely to die in the next few days. These researchers are now speculating about whether there is some kind of protein in humans that allows humans to sleep and recover after stressful events. If there is, and we're resisting it, a sleep deficit could be more serious than we previously imagined.