Jan 11 2006
According to researchers in the U.S., grogginess on waking up in the morning should not be dismissed because it seriously impairs thinking and memory skills.
They warn that this has implications for doctors, firefighters and those who are expected to go straight into action the moment they wake up.
The researchers believe the effects of sleep inertia are as bad and possibly worse than being drunk.
The research team at the University of Colorado at Boulder and Boston's Brigham and Women's Hospital say that people who awaken after eight hours of sound sleep have more impaired thinking and memory skills than after being deprived of sleep for more than 24 hours.
Their research showed that short-term memory, counting skills and cognitive abilities were significantly impaired in the groggy period upon waking, known as sleep inertia.
Dr Kenneth Wright, an assistant professor at Colorado University, says that the study has implications for medical professionals who are often called on to attend to patients at a moment's notice, often at odd hours, and also for safety and transport workers.
The research found that subjects exhibited the most severe impairments from sleep inertia within the first three minutes after awakening.
These effects generally dissipated within the first 10 minutes, although its effects are apparently still detectable for up to two hours.
The performance was found to be significantly worse in people who had just woken up after eight hours’ sleep than those who had been awake for more than 24 hours.
Dr Wright says the effects after 24 hours of sleep deprivation equate with the effects of alcohol intoxication.
The study is the first to quantify the effects of sleep inertia.
The findings are published in the current edition of the JAMA: The Journal of the American Medical Association.