An article posted today at Psychology Today asks an interesting question — Do Cats Dream of Catching Mice? Here at SleepBetter.org, we’re normally more concerned about human sleep, but this is an important question in sleep science. Figuring out how other members of the animal world sleep and dream may help us unlock some of the mysteries of how humans sleep.
REM sleep is associated with episodes of vivid dreaming was and first discovered by Aserinsky & Kleitman in humans during the 1950’s. Awakening people during REM sleep typically results in a report of vivid dream imagery and a complex associated story line. Dream imagery can occur in other sleep states but is typically less vivid and complex. After the REM state was identified in humans, a similar state was discovered by Dement a few years later in cats. As in humans, cats in REM sleep show a low voltage EEG with characteristic eye movements. There is also a loss of muscle tone (atonia), presumably to prevent acting out of the dream content. This striking cross species similarity of brain states and behavior indicated that dreaming may not be limited to or be a uniquely human state of consciousness. In fact, much of the initial work on REM sleep was done on cats and the underlying brain centers involved in REM sleep were discovered in the cat.
Of course, having REM sleep does not absolutely indicate that the same subjective experience of an alternative world of dreams exists in other animals. Yet-anyone who has seen a cat or dog sleep and have some loss of the muscle atonia associated with the REM state must be struck by what looks like an effort to run and move that certainly suggests an ongoing dream.
If they do dream, what do you think your pet dreams about?