One of the major changes that I first experienced as a graduate student was an increase in the numbers of hours I slept. Of course, there was still lab work to do and courses to study for, but my schedule was no longer crammed with 2-3 tests to study for simultaneously, term papers to write, and weekly problem sets to contend with. While graduate school was more challenging in other ways (e.g. what should my thesis be about), life had slowed down in general.
We all know that sleep is important, but how crucial it is to daily functioning shocked me. Graduate students without families who go to school full time without having to work on the side can probably afford to get adequate amounts of sleep. In the rest of the world, however, where one needs to attend to families, work, social commitments and possibly a long commute, sleep is way down on the list of priorities. Some people even boast how little sleep they survive on, and in some circles this is considered a sign of strength. Getting less than 7 hours of sleep a night is probably the norm for adults, rather than the exception.
Now, consider the following question. If you had to stay up for 24 hours straight and were asked to complete a challenging cognitive ability test, how well do you think you would perform? If you are like most people, you would predict that you would not do very well. What if you had to take the same test after getting 6 hours of sleep a night for a week? According to a study reported by Po Bronson and Ashley Merriman in the book "Nurtureshock", people who regularly sleep 6 hours a night do not perform better on tests than those who stayed up 24 hours straight. Both groups scored very low on the exam. So, if you get 6 hours of sleep regularly, your mental ability is no better than if you stayed up for 24 hours straight.
According to Bronson and Merriman, children today get an average of 1 hour less sleep than 30 years ago, most frequently due to extracurricular activities or early classes at school. In a controlled study one group of sixth graders was sent to bed 30 minutes earlier than their normal schedule and another group 30 minutes later than schedule. They were both awakened at their regular times and asked to complete a reading test. The group which received less sleep, scored at the 4th grade level, 2 grade levels below where they should have, whereas the other group scored at their grade level. Schools and families who rearranged the children's schedules to allow for an extra hour of sleep found remarkable improvements in test scores and moods (especially for teenagers).
The story that really shocked me was from John Medina's book, "Brain Rules", where he describes a 17 year old teenager who wanted to get into the Guinness Book of Records by staying up 11 days straight. While no one condoned this experiment, scientists used this opportunity to study the effects of sleep deprivation. During the first few days, he was extremely tired and irritable, and his short term memory started failing. By the fifth day his condition worsened and he started to exhibit tremors and symptoms of Alzheimer's Disease, and had to be hospitalized.
These stories were both a revelation and relief. Now I know why I cannot focus well on certain days - once again I got less than 7 hours of sleep. Ideally, I could use 8-9 hours. While we all have hectic schedules, remember that every extra 15 minutes of sleep count, so any sleep-saving tactic you can use (e.g. less caffeine at night for the whole family, going to bed earlier, less TV, getting organized so you can sleep later) can make a difference.
Wishing you the best,
Dora Farkas, PhD, Founder, PhDNet