Do cats dream?

It’s kind of a magical question, isn’t it? Knowing that cats dream would be a little like seeing inside their minds and understanding them in a deeper, more intimate way.

But, actually, we do know. All the scientific evidence that we currently have suggests that cats dream much the way we do.

And we even know a little bit about what they dream about.

I can’t wait to tell you all about it.

Why does anyone dream?

Dreams are powerful experiences that we have no control over. While our bodies are resting, our minds seem to go into overdrive, creating fantastical stories and visual images that have the ability to evoke deep emotion. After dreaming, we may feel wildly happy, acutely sad, or severely frightened. It’s as though we lived through real experiences, even though we never left our beds.

When do we dream?

Most dreaming happens during a particular phase of sleep, called REM sleep. REM, which is short for rapid eye movement, is when brainwaves are most active while we’re sleeping. We cycle in and out of REM sleep all night long. This information about REM sleep will be important when we discuss cats in a moment.

Studies show that people who are deprived of REM sleep develop anxiety and depression. They have a hard time concentrating, gain weight, become uncoordinated, and have a tendency to hallucinate.[1] In other words, we seem to need our dream-sleep, our REM sleep, to be healthy.

For all that we know about ourselves, we don’t really know why we dream during REM sleep. But there are a few prevailing theories.

Are dreams how we process information?

Many sleep researchers believe that dreaming is how we organize and store information, process our emotions, and even clear our minds of “junk” – incomplete, flawed, or unnecessary information.[2]

Matthew Wilson, associate professor of brain and cognitive sciences at MIT, thinks that dreams are a chance for us to analyze and learn from our experiences. “Replaying a series of pleasant or unpleasant experiences,” he told MIT News, “may allow us to learn what these experiences had in common and use this to guide future behavior.”[3]

Dreaming might also be a chance to kind of rehearse situations we might encounter in real life.[4]

Are dreams how we form long-term memories?

Scientists believe that memories are formed in at least two stages: there’s the initial phase when we actually experience something that we’re going to remember, and then a “consolidation” period when the experience becomes a long-term memory.

Some scientists believe that long-term encoding into memory happens when we “replay” those experiences during sleep.[5]

Are dreams how we protect the visual part of our brains?

There are other theories about why we dream, but there is an idea that dreaming – in which we “see” even though our eyes are closed – could be a way of keeping an important part of our brains, the visual cortex, active even when we are not.

Our brain is amazingly plastic, meaning that it has the ability to change in structure depending upon our experiences. The visual cortex – the part of the brain that usually handles sight – can be “rewired” to help blind people develop incredible hearing, for example.

The visual cortex is so plastic, however, that even blindfolding someone for a short while has been shown to improve his or her sense of touch. Sighted people who are blindfolded learn to read Braille more easily than non-blindfolded people.

For most of history, before the invention of electricity, the world has been dark for 12 hours out of every 24. Is the act of dreaming – a kind of “seeing” with our eyes closed – a way to preserve the visual cortex and keep it from getting “taken over” by the other senses?[6]

There is some compelling research that supports this unusual theory about why we – and maybe even cats – dream.

Cat brains may not be so different from ours when it comes to dreaming

The question, “Do cats dream?” is also a question about humans.

David M. Peña-Guzmán, associate professor at San Francisco State University and author of When Animals Dream: The Hidden World of Animal Consciousness, reminds us that the human mind did not develop in a vacuum. It evolved.

Many of the characteristics that we like to think of as unique to our own species, thanks to our “superior” brains, are traits that can also be found in other creatures. For example, as Diana Kwon wrote in Scientific American, “Monkeys have a sense of fairness. Chimps engage in war. Rats show altruism and empathy.”[7]

Thanks to evolution, our brains have much in common with animal brains, especially mammal brains. It is not likely that our ability to dream is unique to our species.

But just because it’s likely that cats and other animals dream, however, doesn’t mean it’s easy to prove that they do. If you want to know whether another human dreams, all you have to do is ask them.

How do you know if a cat dreams if you can’t ask him?

We have actually asked some animals if they dream

Only two animals have ever actually told their dreams to a person: Koko and Michael, the two gorillas who learned to communicate using American Sign Language.

Koko, upon waking from sleep, would apparently tell the researchers working with her about fantastic events, and places and people that she hadn’t recently been or seen.

Michael, on the other hand, who had been captured when poachers killed his entire family, would wake from sleep and sign, “Bad people kill gorillas.”[8]

Thanks to Michael, we know that some animals have the capacity for nightmares, too.

We have evidence that rats and birds dream

Experiments with rats seem to show that rats dream. In these experiments, researchers measured brain activity in rats learning a maze. They recorded their brain activity when they were asleep, too.

During REM sleep, a rat’s pattern of brain activity so precisely matched the awake-brain’s pattern in the maze, that researchers actually knew where the rats “were” in the maze in their minds when they were dreaming. They could also tell if the rats were running in their dreams, or standing still, based on the brain activity.[9]

A study of zebra finches had similar results. Researchers were able to match the electrical activity in the singing birds’ awake brains, to electrical activity in their brains while sleeping. The same parts of their brain lit up in the exact same order, suggesting that they were singing in their dreams. Their little birdie throats moved in their sleep, too.[10]

Cats have REM sleep, too, just like us

Remember I mentioned how important REM sleep is to dreaming? Well, it turns out that cats have REM sleep, too.

REM sleep in humans was discovered in the 1950s. During REM sleep, a person’s eyes move very rapidly under closed lids. Scientists learned that if they woke someone up during this phase of sleep that they would describe vivid, imaginative, detailed dreams.

A few years after REM sleep was discovered in humans, it was discovered in cats. An electroencephalogram (EEG) test, which measures brain activity, showed that cats have similar brain-wave patterns to that of humans in the midst of REM sleep. Cats also display those characteristic eye movements during REM sleep.[11]

REM sleep, for humans, cats, and other animals, is also characterized by low muscle tone, which keeps us all from acting out our dreams. Your cat may be dreaming about leaping off the top of the kitchen cabinets, but her brain will allow only a paw to twitch.

We might know what cats dream about

Dream researcher Adrian A. Morrison once commented about whether we can ever know what cats dream about, “…who knows what cats are thinking when awake?”[12] That’s my favorite quote about cats and dreaming.

But we might actually know a little about what cats dream about.

We just talked about how our brains have a special mechanism that keeps us from jumping around and acting out our dreams during REM sleep. One of the earliest sleep researchers, Michel Jouvet, conducted an (unfortunate) experiment on cats in which he destroyed the part of their brains that keep them mostly still during REM sleep.

The cats slept quietly throughout all the other stages of sleep, but during their REM cycles, they jumped up, stalked, pounced, arched their backs, and hissed. It looked like they were hunting mice.[13]

If finches can sleep-sing, and rats can dream about solving a maze, I suppose cats can catch prey in their dreams, too.

Do cats dream in color?

Before you can answer the question of whether cats dream in color, you have to understand how cats see the world when awake. In short, cats have fewer cones in their retinas than we do. Cones are the color-perceiving cells.

(But they have tons of rods, instead, which allow them to see well in low light.)

So, cats can perceive color, but the colors cats see are probably kind of dull. We believe that cats see violet and blue well, and that some cats may see green, but that red appears grayish to all cats.

For all the details on cat vision, read this post, “Can cats see in the dark?”

While we can't truly know the content of cats’ dreams, we can assume that they are only able to see colors in dreams that their brains perceive while awake.

Do cats have nightmares?

Michael, the gorilla, gave us some insight into animals’ ability to experience nightmares.

Researchers tried to learn whether rats experience nightmares, too, by conducting experiments designed to conjure up bad dreams. (Don’t worry – it’s not as bad as it sounds.)

Researchers gave rats who were learning a maze a “bad experience” along the way. Using a one of those keyboard cleaners that blow air, they delivered a surprising puff into the face of a maze-running rat.

Researchers were recording brain activity throughout the experiment, and when a rat got a puff of air, his amygdala lit up. The amygdala is the part of the brain responsible for processing emotion.

During sleep, when a rat was “running the maze” in her dreams, her amygdala would light up again, at just the right moment, suggesting that she was reliving this bad experience in her dreams.[14]

Does this same knowledge about rat and gorilla nightmares apply to cats? We can only guess.

Is there a way to prevent my cat from having a nightmare?

We know that there is some correlation, in some species at least, between what is experienced during waking hours and what is dreamed.

It's your job as your cat’s guardian is to ensure that he gets all the sleep he needs in a safe and comfy environment, and to make sure that most of his waking experiences are happy ones.

Is it OK to wake a sleeping cat?

Cats need a lot of sleep. If you need more convincing, read this post about why cats sleep so much.

We also know now how important REM sleep is for health. We should assume that REM sleep is essential for your cat’s health, too.

Rule of thumb: let sleeping cats lie.

If you were interested in this post, you might also want to learn about why cats sleep with their people.

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Dawn LaFontaine is a lifelong animal lover who always seems to have a little pet hair in her keyboard. Her blog, Kitty Contemplations, helps cat guardians better understand and care for the special beings they share their lives and homes with. Her cat-products business, Cat in the Box, sells beautiful, well-made, and award-winning products that she designed to meet the biological needs of cats.

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FOOTNOTES 

[1] Marks, Hedy. “Dreams: Why We Dream, Nightmares, and Lucid Dreams.” WebMD, 5 Nov. 2021, www.webmd.com/sleep-disorders/dreaming-overview.

[2] Suni, Eric, and Alex Dimitriu. “Dreams: Why We Dream & How They Affect Sleep.” Sleep Foundation, 2 June 2023, www.sleepfoundation.org/dreams.

[3] “Animals Have Complex Dreams, MIT Researcher Proves.” MIT News | Massachusetts Institute of Technology, news.mit.edu/2001/dreaming. Accessed 7 June 2023.

[4] “Why Do We Dream?” Cleveland Clinic, 18 Aug. 2022, health.clevelandclinic.org/why-do-we-dream/.

[5] “Animals Have Complex Dreams, MIT Researcher Proves.” MIT News.

[6] Eagleman, David, and Don Vaughn. “Why Do We Dream? A New Theory on How It Protects Our Brains.” Time, 29 Dec. 2020, time.com/5925206/why-do-we-dream/.

[7] Kwon, Diana. “What Makes Our Brains Special?” Scientific American, 24 Nov. 2015, www.scientificamerican.com/article/what-makes-our-brains-special/.

[8] Bender, Kelli. “What Is Your Cat or Dog Dreaming about? A Harvard Expert Has Some Answers.” Peoplemag, 13 Oct. 2016, people.com/pets/what-is-your-cat-or-dog-dreaming-about-a-harvard-expert-has-some-answers/.

[9] Stein, Rob. “Sleeping Rats May Dream of Maze.” The Washington Post, 25 Jan. 2001, www.washingtonpost.com/archive/politics/2001/01/25/sleeping-rats-may-dream-of-maze/0f65aa2a-99aa-47ca-862a-83143124ad3f/.

[10] “Do Animals Dream? With David M. Peña-Guzmán (Ep. 97).” University of Chicago News, news.uchicago.edu/do-animals-dream-david-m-pena-guzman. Accessed 6 June 2023.

[11] “Do Cats Dream of Catching Mice?” Psychology Today, www.psychologytoday.com/intl/blog/sleepless-in-america/201004/do-cats-dream-catching-mice. Accessed 30 May 2023.

[12] Event-related activity and phase locking during a psychomotor vigilance task over the course of sleep deprivation - Wiley Online Library, onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2869.2010.00892.x. Accessed 30 May 2023.

[13] Bender.

[14] Yirka, Bob. “Recording Bad Dreams in Rats.” Medical Xpress - Medical Research Advances and Health News, 12 Sept. 2017, medicalxpress.com/news/2017-09-bad-rats.html.