Washington State University

Ask Dr. Universe

Sweet dreams!

January 6th, 2012

Dear Dr. Universe,
Is there any way to enhance one’s memory?
Anders Okkelmo
Sarpsborg, Norway

Sleeping student. Marc Wathieu/Flickr

Sleeping student. Marc Wathieu/Flickr

Think about this: Think about how much you think about all day long, about how much you see, hear, smell, taste, feel. About how much you have to REMEMBER. All day long your brain is going like crazy. Your neurons (nerve cells) are constantly trading information with other neurons, joining up with them to form memories, on/off, hello/goodbye, information in/information out, and on and on, ALL DAY LONG!

Well, where does that leave your brain at the end of the day? A real mess, that’s what! And probably full of adenosine! Wait, what?

The “currency” of energy in your cells, including your neurons, is molecules called ATP, or adenosine triphosphate. As the brain cells use that energy, the ATP breaks down, leaving all this adenosine floating around in your brain. Some scientists think that adenosine triggers sleepiness.

Well, let’s suppose it does. What could this tell us about improving our memories?

I went to talk to Gina Poe, who also helped us understand stereotypes and memory. Professor Poe is an electrophysiologist, which means she measures the activity of neurons. Neurons make up most of your brain. Neurons work by communicating with each other through electrical and chemical signals that move from one neuron to the next along their synapses (SIN-ap-sees).

Professor Poe is very interested in the effect of REM sleep on memory.

REM stands for “rapid eye movement,” which describes what you do about an hour and a half after you go to sleep. During this phase of sleep, your eyes are darting around like crazy, reflecting what’s going on in your brain. Even though you are deep in sleep—and your body is actually paralyzed—your brain is just as active during REM sleep as it is while you’re awake.

Specifically, Professor Poe wonders “Is REM sleep for remembering or forgetting?” Forgetting? Well, think about it. What if you didn’t forget? Have you ever thought, “Whoa, my brain is full”? According to Professor Poe, your neurons CAN fill up. But no, you can’t use this as an excuse in class. (Your teacher is probably reading this, too, and SHE’LL know that all you need to do is get a good night’s sleep!)

So WHAT in the world is going on in there?

You’re dreaming.

But why? Why do we dream?

Professor Poe thinks that REM sleep is when your brain cleans house, when it puts things in order. Not only does it strengthen important memories, it cuts out unnecessary ones.

So how does she know this?

She studies rats and what happens to them during REM sleep. She has them run around this raised rectangular track, which has six food cups around it. Only three of them have food in them, though, so it takes the rats a while to remember which ones do.

After they have it all down, Professor Poe tests how well they remember when they don’t get enough sleep. Of course, it’s not very well. But she wants to know why. What’s the connection between memory and REM sleep?

She studies this by using probes and computers to measure how the rats’ neurons act during REM sleep.

What she’s learned so far is that neurons FIRE at different times, depending on whether they want to strengthen a memory or forget it! So again, REM sleep cleans up your memory.

So how do you enhance your memory? Tidy up your brain and GET ENOUGH SLEEP. Sweet dreams!