Scrutable

https://twitter.com/CaliaDomenico/statu ... 83456?s=09

A marine biologist films this octopus changing colors while dreaming and it’s spectacular

I thought "A sleeping octopus changes colour as she dreams" sounded like the title of something by Harold Budd.

basementer wrote: Sun Nov 17, 2019 7:32 pm I thought "A sleeping octopus changes colour as she dreams" sounded like the title of something by Harold Budd.

Or captain beefheart, in one of his straighter moments

I thought the extremely mundane explanation from the marine biologist added to the charm...she is dreaming of catching a crab.

I'm interested to know how they can tell that it's dreaming.

Bird on a Fire wrote: Tue Nov 26, 2019 9:42 am I'm interested to know how they can tell that it's dreaming.

I guess it’s possible to tell if an octopus is asleep, in which case how else would you explain all the colour changes etc?

Grumble wrote: Tue Nov 26, 2019 1:05 pm

Bird on a Fire wrote: Tue Nov 26, 2019 9:42 am I'm interested to know how they can tell that it's dreaming.

I guess it’s possible to tell if an octopus is asleep, in which case how else would you explain all the colour changes etc?

The concept of "asleep" is a bit complicated (even in mammals), what with unihemispheric sleep in dolphins, birds, fish, etc.

But it appears that octopuses may have REM sleep, as measured by brainwave activity. Cuttlefish do have REM sleep including the eye movements.

Edit to add: second link, which is a nice article.

Grumble wrote: Tue Nov 26, 2019 1:05 pm

Bird on a Fire wrote: Tue Nov 26, 2019 9:42 am I'm interested to know how they can tell that it's dreaming.

I guess it’s possible to tell if an octopus is asleep, in which case how else would you explain all the colour changes etc?

I'm just not convinced that "hallucinating catching a crab" is necessarily the most parsimonious explanation.

In humans, the only animal whose dreaming behaviour we can easily study, most (and the most vivid) dreaming occurs during REM sleep when the body is necessarily paralysed. Excessive movements during dreams are characteristic of sleep disorders.

So for example when people see their dog kicking around in it's sleep they like to think it's dreaming about chasing rabbits or whatever, when in reality it probably isn't dreaming at all, but there's no way of telling.

I would assume that octopus skin colour can change due to some hormonal process without needing direct cognitive control, and there's no reason hormone levels can't change during sleep without accompanying hallucinations.

But I'm not an octopusologist, sleep scientist or anything else relevant.

Bird on a Fire wrote: Tue Nov 26, 2019 1:40 pm

Grumble wrote: Tue Nov 26, 2019 1:05 pm

Bird on a Fire wrote: Tue Nov 26, 2019 9:42 am I'm interested to know how they can tell that it's dreaming.

I guess it’s possible to tell if an octopus is asleep, in which case how else would you explain all the colour changes etc?

I'm just not convinced that "hallucinating catching a crab" is necessarily the most parsimonious explanation.

In humans, the only animal whose dreaming behaviour we can easily study, most (and the most vivid) dreaming occurs during REM sleep when the body is necessarily paralysed. Excessive movements during dreams are characteristic of sleep disorders.

So for example when people see their dog kicking around in it's sleep they like to think it's dreaming about chasing rabbits or whatever, when in reality it probably isn't dreaming at all, but there's no way of telling.

When you get to mammals, is there any reason to think humans, or even primates would be unique, given how ancient sleep itself is? Obviously that's different from assuming that's the explanation, but I'd have thought it was a parsimonious explanation.

But then I'm not even a biologist.