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What Lack of Sleep Does to Your Mind

Sleepiness can damage your judgment, work performance, mood, and safety.

The Impact of Chronic Sleepiness continued...

2. Excessive sleepiness impairs memory. Research suggests that the nerve connections that make our memories are strengthened during sleep. “Sleep embeds the things that we have learned and experienced over the course of the day into our short-term memory,” says Avelino Verceles, MD, assistant professor at the University of Maryland School of Medicine and director of the school’s sleep medicine fellowship.

It appears that different phases of sleep play different roles in consolidating new information into memories. If your sleep is cut short or disrupted, it interferes with these cycles.

When you’re sleepy, you may forget and misplace things often. And the inability to focus and concentrate caused by sleepiness further weakens memory. “If you’re not able to concentrate on what’s at hand, it’s not going to make it into your short-term memory and then long-term memory,” says Allison T. Siebern, PhD, a Fellow in the Insomnia and Behavioral Sleep Medicine Program at the Stanford University Sleep Medicine Center.

3. Poor sleep makes learning difficult. Sleep deprivation affects your ability to learn in two ways. Because you can’t focus as well, it’s more difficult to pick up information, so you can’t learn efficiently. It also affects memory, which is essential to learning. In children, sleepiness can lead to hyperactivity, also hampering learning. Teens may lose the focus, diligence, and memory capacity to perform well in school.

The Biggest Danger of Sleepiness: Slowed Reaction Time

Sleepiness makes your reaction time slower, a special problem when driving or doing work or other tasks that require a quick response. The National Highway Traffic Safety Administration conservatively estimates that at least 100,000 crashes reported to police each year are due to driver fatigue. Other estimates put that number at 1 million -- 20% of all crashes. Nearly one-third of Americans in the National Sleep Foundation’s 2009 poll reported nodding off while driving.

You don’t need to fall asleep at the wheel to be a danger -- drowsiness alone can be as dangerous as driving drunk. Driving while sleepy is like driving with a blood alcohol content of .08% -- over the legal limit in many states. And drinking and drowsiness are double trouble when driving because sleep deprivation magnifies the affects of alcohol.

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