Jan. 11, 2006 — It's no wonder coffee is such a popular morning drink. A new study shows that the grogginess we experience when we first awake from sleep may affect our ability to think clearly, known as "sleep inertia."
The study, published in Tuesday's issue of the Journal of the American Medical Association, is especially important for people who are expected to perform immediately upon awakening — such as physicians, pilots, truck drivers and military personnel, said lead author Dr. Kenneth Wright, of the University of Colorado at Boulder.
The study involved nine healthy individuals who stayed at a sleep laboratory for several nights. After a full night's rest, they were awakened and given a simple math test, variations of which were repeated for the next 24 hours.
The researchers noted that the people in the study performed the worst within the first three minutes of awakening. Previous studies have shown that sleep inertia may affect cognitive performance for up to two hours, the study authors note.
Dr. William Dement, director of Stanford University's Sleep Disorder Clinic, called the study "very important" — especially for doctors in training, who are often required to make quick, critical decisions upon awakening.
"There are mistakes that are made in the medical field because of fatigue," he said."
This has long been a real concern of mine. Some people can do very well on limited sleep and others just lose all of their capacity to make good decisions.