Animals Also Dream Images

You thought that only us, humans, can dream porn?

Or be kings of the hill while dreaming?

Wrong!

Animals can do it, too.

Researchers at the Massachusetts Institute of Technology (MIT) found out that when rats take a nap, they replay "movies" of their day action in their dreams.

And like in humans, memories are cemented into the brain while sleeping.

"This work brings us closer to an understanding of the nature of animal dreams and gives us important clues as to the role of sleep in processing memories of our past experiences," said co-researcher Matthew Wilson.

Wilson found on previous studies that rats do form memories of events they experienced while awake, and that the rodents replayed the memories while snoozing but he could not prove that they were dreaming vivid images, like in humans, to form a memory movie.

To find out, Wilson and Daoyun Ji checked brain activity in the hippocampus (the memory center of the brain) and visual cortex while rats ran through mazes with different designs on the floors and walls.

The brain regions showed specific activity patterns as the animals sensed their surroundings in the maze.

Then, the researchers watched the activity patterns of the same brain zones while the rats were sleeping.

Sleeping rats re-scanned a string of images showing the maze-running experiences.

The patterns of neuronal activity while awake emerged equal during sleep in the visual and memory regions.

Also, the scientists recorded activity of individual neurons in the rats' brains while the animals were awake and asleep.

The same neurons spiked during wakeful action got reactivated during sleep.

It's like during sleep, neurons in the visual region pass information to those in the hippocampus in a sort of "conversation," suggesting that rats' sleep helps consolidate daily experiences and makes memories stick, just like in humans.

This investigation points for the first time that the brain is storing memories in two locations at once: in the visual and memory centers.