Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Ries van Twisk on 20/12/2016 09:49:45
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Ries van Twisk asked the Naked Scientists:
Chris,
Obviously, always listening to your shows (http://www.thenakedscientists.com/HTML/podcasts/) with my two cats laying, sleeping and dreaming next to me....
Now I was wondering... I have sometimes bold dream that I can fly, or cannot run... or just weird oddities I cannot explain really, but well.. they are there...
Now I was wondering... A lot of animals also dream, clearly seen from my cats, they might dream about huge bags of cats foot, may be they dream they can fly like a bird, to catch them properly...
But, what do they dream? Was there every a study on it?
Is this possible? I can imagine some sounds can get analyzed to see if that's
different them there normals dreams... But , do animals also have weird dreams?
Ries
What do you think?
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This is one for @atrox or @SquarishTriangle I think!
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It's quite difficult to establish exactly what an (awake) animal is thinking, and to validate our assumptions (using existing technology), given that most animals do not speak human. We can sort of make some broad assumptions about what an awake animal might be thinking based on the environmental situation and body/facial language patterns, but who's to know if we are completely wrong? It would be even harder to communicate with a sleeping animal, since there is largely an absence of body language during sleep. And they will never tell you what they dreamed about afterwards, in order for you to validate your theory.
Some dogs appear to run during their sleep. Whether they are dreaming about running through the fields, or if it's simply a spontaneous outburst of memorised muscle movement: hard to say. While it's easy to jump to the conclusion (with a little anthropomorphism) that a cat that licks its lips during sleep might be dreaming about food , I've never seen a cat chatter during sleep, as they often do while hunting birds, or hiss and swipe as they often do in a fight. So, if cats do indeed dream about these topics, it doesn't seem as though those dreams consistently translate into observable muscle movements.
What constitutes a "weird dream" anyway? In my (human) experience, a 'weird' dream is usually one in which the events or behaviours of the characters deviated from what is expected or socially acceptable. My opinion is that animals don't tend to have as many rules and expectations as humans have constructed for themselves. So, while we might think that waking up very late, walking around naked in public, eating some random old faeces, licking one's own anus, and then mating with a sibling would be a pretty crazy dream...perhaps not so weird if that any/all of that occurred in an animal's dream.
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Hi Ries,
as SquarishTriangle already pointed out, it is of course difficult to impossible to determine what an animal dreams. At least at the moment, it would be impossible to know what other people dream, if they would not be able to tell us about it.
From my annecdotal experience and a very anthropocentric point of view I believe that at least dogs do dream, and I would guess, that they also have very engaging dreams. I crew up with dogs and especially our first dog used to have quite intense situations during sleep involving running movements, snarling, growling, rapid eye movements, fawning, gasping and slight forms of barking regularly. In one case she even howeld like a wolf, a sound I never heard from her before or after that dream again. That was super weird and I swear (anthropomophizingly of course :-)) she had a very confused look in her face when we woke her up from this. Our other dogs also show some of those mentioned signs that would lead me to think that they dream.
However, this is purely annecdotal, even if many other pet owners can add their own stories to this.
Science also tried to tackle that question, if animals do dream at all.
We know from comparing EEG patterns of sleeping animals that many mammals and birds follow similar sleep patterns like humans with deep REM sleep phases alternating with lighter non-REM sleep phases. In humans the REM phases are the ones were we dream and it has been shown, that they are essential for memorizing.
The movements during sleep is one of the best observable hints we have for actual dreaming. There is a sleeping disorder in humans, where muscles will not be paralysed during REM-sleep, so that dreams get acted out by walking, punching, kicking.. This disorder exists also in domestic animals, suggesting that they do dream as well (you can finde videos of such animals if you search for REM sleep disorder in animals). Scientists also induced this disorder artificially to study cats during sleep in the 1960s, observing those animals acting out during REM-sleep, including walking an dfighting invisible opponents.
Some more studies are done on brain activity during sleep, showing in rats, that they relive their daily experiences and in zebra finches, that they memorize their bird songs during REM sleep.
So there is quite some behavioural and neurologcal evidence for animal dreams. Given the nature of dreams from our human experience, there is so far no reason to believe, that animals would exclusively dream of "normal" things, althought their "weird" might be something completely different from what we would expect it to be. However, in the end nobody knows and it might be impossible to ever know.