Trying to learn a new skill? Striving for a promotion? Studying for a test? Start by getting a good night’s sleep! Sleep is not only physically restorative, but also crucial to learning and memory. The average adult needs seven-and-a-half to nine hours of sleep per night for optimum functioning, but in our busy, 24/7 world, most people are walking around sleep-deprived.

Generally, we need one hour of sleep for every two hours we are awake. By not getting enough rest, we rack up a cumulative sleep debt. The longer you deprive yourself of sleep, the more of it you will need to feel rested. Even just a little sleep loss can severely compromise your learning ability, memory consolidation, creativity and problem solving skills. In fact, there is a 19 percent memory deficit in most sleep-deprived individuals. This means that they are only operating at 80 percent of their full potential!

Sleep is when the brain’s two memory systems—the hippocampus and the neocortex— “talk” with one another to exchange information. In the first two hours of sleep each night, any experiences from the day that will become memories are laid down in the hippocampus. In the next four hours, memories that are going to be retrained are moved to the neocortex. The neocortex is where experiences and memories gain physical permanence. Getting enough sleep for this transfer to occur is crucial to learning and memory!

From passing thought to permanent memory: Sleep is the best time for the transfer of material between the hippocampus and neocortex because the hippocampus is not “distracted” during sleep like it is while awake. Sleep is also the best time for the neocortex to link new material to related memories.

If you cut your personal sleep need short, you will find it more difficult to recall information or memories. This occurs because the final two hours (of an eight-hour sleep) are when REM (rapid eye movement) sleep and REM replay take place. During those crucial hours of sleep, your brain replays new material over and over again for maximum retention. So, even when you are sleeping, your brain is helping you learn!That’s not all your brain is doing at night. Sleep is also important for memory consolidation, which is when your brain filters out any unimportant new information and cross-references the remaining essential information with what’s already on file in your brain. Making connections to what you already know is necessary for recalling the information later and adds to your critical and creative problem-solving abilities. This period is also when your brain processes information and replaces any material that you may have temporarily forgotten.

READ MORE: Sleep Deprivation and Daily Living, from James Maas, Ph.D.

Your brain knows when you need more consolidation time. Research shows that the night after a day of learning, the amount of time you spend in REM sleep naturally increases. Those final two hours make a huge difference in how much material you thoroughly learn. Six hours of sleep may be enough to retain some information, but it takes at least eight complete hours to fully incorporate learned material.

 Learning while you sleep: fact or fiction? Unfortunately, it’s impossible for you to acquire new material while you sleep. Your brain can only process and rehearse the new information you learned prior to falling asleep. While you cannot learn a new language by listening to tapes of it while sleeping or practice for a presentation by sleeping with your notes under your pillow, you can improve your memory by reviewing new material right before going to bed. “Sleeping on it” has been shown to improve performance for optimum memory retention!

When to sleep: Sleeping well before learning and sleeping well after learning are both very important. If you don’t get enough REM sleep prior to learning new material, your ability to establish memories may be hindered. Also, not getting enough sleep disrupts your hippocampus and reduces your ability to think conceptually.

Sleeping after learning is most crucial, since that is when memory enhancement occurs. Research shows that subjects who were deprived of sleep the night after learning new material did not show any signs of improvement even after two subsequent nights of sufficient sleep. So, the next time you’re cramming for a test or prepping for an interview, make sure you sleep well before and after learning the material you need to retain.

Creativity: People who are well rested have been shown to gain insight into a problem much faster than those who stayed up all night trying to find a solution. Dreams have long been inspiring discoveries and inventions that changed the world. Without sleep and dreams, Paul McCartney never would have written “Yesterday,” Mendeleev wouldn’t have finished the periodic table, and the Nike brand name would not exist. So, if you are struggling to finish a paper or come up with an idea for something, your answer may be found in a solid eight hours of sleep!

READ MORE: How Much Sleep Do You Really Need?

Bottom Line: No matter how smart you are, losing sleep means losing brain power. Failing to meet your personal sleep quotient can have serious effects on more than just your ability to learn material and remember what you previously learned.When you are sleep deprived, parts of your brain do not function properly (or at all). You are essentially walking around with a “mental limp,” and the more sleep deprived you are, the worse the limp! A recent study affiliated with the University of Wisconsin-Madison showed that some neurons in the brains of rats that are normally turned “on” while awake suddenly went “offline” when sleep deprived. The rats were awake, but parts of their brains shut down and acted as if they were asleep!

What should you do? Sleep better and sleep more to improve your learning and memory. Most people only need to add an extra hour of sleep per night to feel fully alert the next day. Changing your schedule to make time for more sleep will take several weeks, but eventually you should be able to wake up fully rested—without an alarm clock! You should feel a notable difference in your health after just a few nights of meeting your personal sleep quotient. Soon you will be less stressed, more alert, and ready to learn! James B. Maas, Professor of Psychology and Weiss Presidential Fellow, Cornell University, is co-author of Sleep for Success! Everything You Must Know About Sleep But Are Too Tired to Ask

[AuthorHouse 2011]Co-author Kristina Shultz is a research assistant working on sleep at Cornell University.