It's a Rat Race

Four rats, after running a very specialized maze during the day, were hooked up to a device that measured the neurons firing in their brains in an area called the hippocampus. The same neurons fired in the same pattern as when the rats were actually running through the maze.

The hippocampus is involved with memory. Perhaps the rats' dreams of running the maze are storing the memories of the maze in permanent memory.

People tend to remember things better if they sleep after learning them. Students who study in the evening and then get a good night's sleep usually retain more of what they studied than those students who cram all night and go to class without adequate sleep.

Is this the same learning technique as observed in the rats?
Another theory is that people use sleep to solve problems.

Have you ever had something to solve, gone to sleep with the problem on your mind and awakened in the morning knowing the solution? How often have you said, "I'll have to sleep on it?"

Research into rats and dreams continues at MIT. It is hoped that the research will reveal how waking life affects dreams and memories.

But rats aren't the only creature being studied for sleep and dream information.

It's for the Birds

Birds, like every other living creature, need sleep. When they're tired, after a big meal, or just because they've been awake for several hours, birds tuck their head beneath their wings and nap. They move around a bit, ruffle their feather, even talk or sing in their sleep.

And how do birds manage to sleep on those little perches without falling off? This is because of a special tendon in their legs that reaches from thigh to toe. When the bird sleeps, the knee bends, the tendon pulls tight and clasps the toes around the branch. Some birds sleep standing on one leg.

Some birds sleep in short bursts, and some, like swifts, even sleep while flying.

Like people, most birds like it dark when they sleep. Bright lights can give birds insomnia and they'll sing away at all hours of the night.

Birds have another special "power." They can sleep with one eye open. This is called unihemispheric sleep, and what it means is that half the brain is asleep and the other half awake. This gives them the ability to watch for enemies and still catch up on their sleep. Birds aren't the only creatures with this ability. Dolphins and seals can swim while asleep.

Even human beings have a vestige of unihemispheric sleep. It shows up in sleep disorders such as sleepwalking where sometimes the person performs intricate tasks while asleep.

At a lab at the University of Chicago, researchers studied zebra finches to determine whether sleep and dreams might be involved in the way they learn the songs of their parents.

Again, the firing of neurons while the birds were awake and listening to their songs was very similar to the way the neurons fired while the birds slept. This may indicate the way the brain commits memories to a deeper, more permanent level.