Domestic cat larynges can produce purring frequencies without neural input | Hacker News Reader

Domestic cat larynges can produce purring frequencies without neural input

cell.com

38 pointslnyan41 comments

My understanding is that cats purr both as an expression of happiness (like when petted) but also when sick, presumably for self comfort.

Both of my cats without fail will gravitate towards me or my gf when we are sick and sit on our chests and purr. it's very sweet.

I can produce a purring sounds in the very back of my throat but my gf can't no matter how much she tries/practices. I speak German natively and the purr is very similar to the sound of the letter "r" which I guess a lot of English speakers have trouble with.

Everyone should be able to roll their r's, but many people have a disconnect because they think it is done by moving their tongue and that misunderstanding prevents them from figuring it out.

It's done by cupping your tongue to the roof of your mouth and blowing air through the cup, the pressure builds up and then suddenly releases, and if done correctly it will vibrate and make a purring, rolling r sound.

The sides of your tongue abut your teeth on the sides and stay firm, but the tip only gets a little pressure to return to the roof of your mouth.

Another trick for practicing rolling Rs is to replace the r in a word with a d. This works best if the R follows another consonant. So when practicing to roll your R don't say "bread" but try saying "bdead". If you manage to make that bd fast enough it'll turn into a sort of tongue slap that's a single "roll". From there it's simply a matter of practice until you can roll as long as you like.

Thats how people have always explained making the rolling R sound for Spanish to me which is different from a rolling R sound in German. I was never able to make the Spanish r sound when I took it high school.

In the "guttural R" used in German the sound is made in the back of the throat without the need to press ones tongue against the roof of the mouth; just the base/root of the tongue against the uvular.

https://en.wikipedia.org/wiki/Guttural_R

This video explains it well with really fascinating videos clips showing a cross section of the mouth live while speaking. The whole thing is interesting but the main difference is shown at 3:30

https://www.youtube.com/watch?v=mRKvpqOEbvU

Love the journal current biology. Extremely accessible yet thought provoking science.

It’s way more readable than the “broad audience” Cell, Nature, Science journals.

What do they mean by "neural input?" Do they mean a voluntary, willful mode of making the sound, as opposed to involuntary process, like breathing?

From the looks of it it's just oscillation caused by breathing in certain ways, so yes, part of the autonomic nervous system, rather than something the cat chooses to do.

The wording makes it sound like this is not all purring though, so there may be other ways cats can conciously choose to purr.

When considering its purpose, does anyone else find something distasteful (to put it much too politely) about the whole idea of this experiment?

And then there's this. https://www.wired.com/story/neuralink-uc-davis-monkey-photos...

No, this is 'science', following decent ethics - deceased animals that were donated to science by their owners.

Perhaps discovering the source of purring isn't the deepest mystery cats could unlock via donation, but it's ethical, and might give us some insights into how the 'healing properties' observed by cat purrs works, or how to mimic it, either for vetinarian, or human medical purposes.

Whereas neuralink is just killing healthy animals for eventual profit.

Do you mind being more precise about what you find distasteful about it? The paper writes that the larynges came from animals that were deceased due to illness:

  The larynges were harvested from animals that had to be euthanised due to terminal disease unrelated to the respiratory tract in veterinary clinics in Vienna, Austria. The animals’ owners gave their explicit consent for the larynges to be investigated postmortem.

This seems quite different from Musk’s Neuralink to me but I might be missing something.

In this case it was done in Austria, and on excised larynges of postmortem pets.

> The animals’ owners gave their explicit consent for the larynges to be investigated postmortem.

I can’t quite make out from the paper but did they just kill eight cats and remove their larynx for this experiment? Was it really worth doing that to determine this? I don’t think learning this was worth even eight cats dying and being mutilated if so. I’m from academia and science and I keep getting more disillusioned with the whole thing the longer I’m in it.

The larynges were taken from euthanised cats that had terminal diseases.

Would you presume murder, if a scientist worked on a human cavadier?

It depends on the maturity of the field. In the 1800s? Absolutely. Animal rights are behind that of humans in the 1800s (yes I know human slavery was common at that time, and that’s my point, humans were treated as property and not as people with rights, which is how our legal frameworks view non-human animals now)

No reasonable scientist would have been murdering people in the 1800s...

I doubt there were many "reasonable scientists" in the 1800s.

Sure, you get someone else to do that[1]. Don't ask, don't tell of course.

[1]: https://en.wikipedia.org/wiki/Burke_and_Hare_murders

I have… bad news: https://en.wikipedia.org/wiki/Burke_and_Hare_murders

Rule of thumb, when dealing with the 19th century: assume pretty much any level of cruelty, depravity, or plain stupidity was up for grabs (you have all three here, the stupidity being around the laws which made this industry inevitable). It wasn’t a very nice time, in general.

That is a pretty naiv assumption.

Congrats you found one example. I could probably list a dozen from recent times too.

Why would you assume that? A, nobody wants to murder eight cats. B, it'd probably be illegal.

> The larynges were harvested from animals that had to be euthanised due to terminal disease unrelated to the respiratory tract in veterinary clinics in Vienna, Austria. The animals’ owners gave their explicit consent for the larynges to be investigated postmortem.

And then they mounted them on Legos.

> After removing excess tissue and all but four tracheal rings, each larynx was mounted on a vertical tube that could supply heated (∼37°C) and humidified (100% humidity) air. Larynx stability was maintained with an adjustable plastic support structure (using LEGO blocks, Billund, Denmark) and 3D-printed plastic mounts.

they probably needed something reliable

Pride of place on the mantlepiece along with a Death Star and Saturn 5 lego set. Head to https://ideas.lego.com/ to realise the dream...

> A, nobody wants to murder eight cats.

Many people embrace the idea of murdering more than just eight cats and actively develop better methods to do so:

https://www.abc.net.au/news/2020-05-29/feral-cat-management-...

https://www.scimex.org/newsfeed/felixer,-the-grooming-trap,-...

    A feral cat management device that uses lasers and sensors to specifically target cats has been shown to be effective in a field trial in remote South Australia.

Well yeah, in Australia cats are an invasive species and a danger to local wildlife, so the situation is a bit different than in other parts of the world.

Domestic cats are essentially introduced | invasive everywhere surely?

    It turns out that domesticated cats have no native range. Originally bred from wild cats and introduced to North America by European colonists, domesticated cats are now listed as one of the top 100 invasive species worldwide by the International Union for the Conservation of Nature.

https://www.cbsnews.com/news/cats-invasive-species-in-your-b...

It's not just Australia they were introduced into.

In most European countries there is no "original" nature left (many thousands of years of humans changing the environment) so talking about invasive species etc. in relation to cats doesn't really make sense there.

In the context of a claim that Australia is unique in considering domestic cats invasive most European countries are irrelevant given the entire New World as sufficient counter example.

The post I replied to makes a broader point than just Australia ("invasive everywhere").

The post you replied to questioned whether they were considered invasive everywhere and asserted that they were on a global list of the 100 worst invasive species.

All as counter to the claim that Australia was unique in considering cats a nuisance.

It seems that assertion is true:

    38. Felis catus

    Felis catus was domesticated in the eastern Mediterranean c. 3000 years ago. Considering the extent to which cats are valued as pets, it is not surprising that they have since been translocated by humans to almost all parts of the world.

    Notable predators, cats threaten native birdlife and other fauna, especially on islands where native species have evolved in relative isolation from predators.

    Common Names: cat, domestic cat, feral cat, Hauskatze, house cat, poti, pusiniveikau

GLOBAL INVASIVE SPECIES DATABASE

http://www.iucngisd.org/gisd/100_worst.php

Is there nowhere in Europe where cat populations are kept in check to protect birdlife and other local native species?

The post didn't question that, it raised the question if they should not be considered invasive everywhere/or at least it can be read like that.

In Western Europe, not really to that end other than quite localised.

But even then the discussion has to be what is a native species (with birds that can get quite odd with species disappearing and reappearing hundreds of years later, for example). There is just no real nature left, i.e., more about deciding when to make a cut.

This has to be one of the wackiest takes on cat domestication I have ever read. Cats were domesticated long before Europeans showed up in North America.

That's exactly what the admittedly clumsy quote says if you reparse it.

> Originally bred from wild cats

Once wild, now domesticated ..

> introduced to North America by European colonists

what was introduced to North America?

> domesticated cats are now listed as ...

oh, yeah, domesticated cats were introduced to North America.

https://news.ycombinator.com/item?id=37775459

Nobody is unfortunately wrong. I know a few real life stories about young boys murdering cats in all sorts of weird and horrifying ways. Some kids are unbelievably cruel.

They were already dead cats.

From the material and method section:

  > The larynges were harvested from animals that had to be euthanised due to terminal disease unrelated to the respiratory tract in veterinary clinics in Vienna, Austria.

Schrodinger has entered the chat

They didn't kill any cats but also as a long term and very loving cohabiter with multiple cats, they are just cats.

Animal cruelty is a serious problem because it makes some people miserable to see them suffer and the ones it doesn't make miserable are possibly dangerously psychotic.

This isn't that.

i’m genuinely curious about how you feel about killing insects in the name of academia and science. the same?

Reply on news.ycombinator.com