to require for optimal daytime functioning. Even so, many sleep
researchers contend that inadequate sleep is widespread in the
contemporary world. Throughout most of human evolution, people
probably retired to sleep not all that long after sunset, even though
the domestication of fire did make it feasible to stay up late. And
generally folks would arise at sunrise to begin their day. Today, with
electric lighting and all sorts of entertaining activities that last late
into the night, we tend to go to sleep later than we otherwise would
yet still usually awaken early the next day to go to work or school. Co-
pious consumption of coffee, tea, energy drinks, and other caffeinated
beverages assists in maintaining wakefulness. However, caffeine is no
substitute for adequate sleep.
Getting insufficient sleep definitely impairs cognitive and
motor performance. This may simply mean suboptimal or fatigued
performance in one’s job or studies, with no terribly serious con-
sequences. However, there are circumstances in which slowed or
impaired judgment, decision making, or motor reactions can have
serious consequences. Automobile accidents and airplane crashes
have been linked directly to sleep deprivation on the part of the driver,
pilot, other critically important crew member, or air traffic controller.
Errors in decisions concerning medication and surgical mistakes
due to sleepiness have resulted in disability and death of patients in
hospitals. If you are doing something in a situation where wakeful-
ness is essential—such as driving a car or performing clinical care ina
hospital—note this rule to live by: “Drowsiness Is Red Alert!” (so says
pioneering sleep researcher William Dement).
Why is sleep so important, other than the fact that we are seriously
impaired if we don’t get enough of it? Whatever these impairments
in cognitive and motor performance might be, they appear to be cor-