Quality of waking hours matters.

• Position: Your Life - Brief article

The quality of wakefulness affects how quickly you fall asleep, the University of Texas Southwestern Medical Center, Dallas, reports in a study that identifies two proteins never before linked to alertness and sleep-wake balance.

"This study supports the idea that subjective sleepiness is influenced by the quality of experiences right before bedtime. Are you reluctantly awake or excited to be awake?" says principal author Masashi Yanagisawa, professor of molecular genetics and a researcher for Howard Hughes Medical Institute, Chew Chase, Md.

Coauthor Robert Greene, professor of psychiatry and a physician at the Dallas VA Medical Center, indicates the study is unique in showing that the need for sleep (called sleep homeostasis) can be separated from wakefulness both behaviorally and biochemically, meaning the two processes now can be studied individually.

"Two of the great mysteries in neuroscience are why do we sleep and what is sleep's function? Separating sleep need from wakefulness and identifying two different proteins involved in these steps represents a fundamental...