FRIDAY, June 25 (HealthDay News) -- How many pet owners have gotten a chuckle out of watching their dog sleep while its paws race frenetically in place?
Many figured that Rover was romping somewhere in dreamland, and scientists say they were right: Pets do dream while sleeping.
As dogs and cats doze, images of past events replay in their minds much the same way humans recall experiences while dreaming, said Matthew Wilson of MIT's Picower Institute for Learning and Memory in Cambridge, Mass. That's because the hippocampus, a part of the brain involved in memory, is basically wired the same way in virtually all vertebrates and mammals, he said.
"If you compared a hippocampus in a rat to a dog; in a cat to a human, they contain all of the same pieces," said Wilson, an associate professor of brain and cognitive sciences.
Like people, pets go through multiple stages of sleep, from periods of slow wave sleep to REM (rapid eye movement), where most dreaming occurs.
"From the minute your head hits the pillow and you're out, the dreaming process begins," he said.
Non-REM dreams consist of quick snapshots of things usually done that day. During the deeper sleep state of REM, dreams last much longer and tap into a vast pool of past experiences drawn from weeks, months, even years in the past.
REM occurs approximately every 90 minutes in people, and every 25 minutes in cats.
In dogs, research shows the frequency and length of dreams is linked to their physical size, said psychologist Stanley Coren, author of several books including How Dogs Think: Understanding the Canine Mind.
For example, he said, mastiffs and Great Danes might dream every 45 minutes for about five minutes, compared to their smaller canine cousins that enter a dream state every 10 minutes with episodes lasting less than 60 seconds.
Owners can tell if their dozing d
All rights reserved