Sleeping Octopuses [Octupi?] May Have Dreams, But They’re Probably Brief
NPR | March 25, 2021| Nell Greenfieldboyce [sic]

Octopuses have alternating periods of “quiet” and “active” sleep that make their rest similar to that of mammals, despite being separated by more than 500 million years of evolution.

. . . and a few feet of sand.

During their active periods of sleep, octopuses’ skin color changes and their bodies twitch, according to a report in the journal iScience, and they might even have short dreams.

So did we, before Biden-Harris.

“If they are dreaming, they are dreaming for up to a minute,” says Sidarta Ribeiro, a neuroscientist at the Brain Institute at the Federal University of Rio Grande do Norte in Brazil.

“And if they are not dreaming,” he added, “well, who knows how long that could last?”

It’s been clear for awhile that octopuses can change color as they sleep; videos of this have even gone viral. And previously, other groups had suggested that cuttlefish have an active sleep state similar to the rapid eye movement (REM) sleep seen in birds, mammals and some reptiles.

“Groups” being a pretty loose term for guys at bars.

But those researchers did not check to see if the creatures in that state would respond to something like prey, says Ribeiro, which left open the possibility that the animals were actually in a state of quiet alertness.

or not on the menu that night.

Ribeiro and some colleagues decided to video-record four adult octopuses in the lab to monitor their sleep. And to make sure the animals were genuinely sleeping, the researchers checked to see if they would respond to a video of a swimming crab, a favorite food item, or to a vibration made by a hammer tapping on the tank.

Um . . . careful with that hammer, OK?

The octopuses remained indifferent and difficult to arouse while sleeping, instead of reacting as they normally would when awake. The scientists found that the octopuses had periods of quiet sleep, when they were pale and still, followed by short bursts of active sleep. This cycle repeated every 30 to 40 minutes.

The active sleep periods were brief but obvious; the octopuses’ skin darkened and their bodies and suckers contracted.”For around 40 seconds, they dramatically change their color and their skin texture. Their eyes are also moving,” says Sylvia Medeiros, a graduate student at the Brain Institute of the Federal University of Rio Grande do Norte. “All of this happens very conspicuously.”

Yep. I imagine I’d be described much the same way if an alien creature was tapping on my life-support system with a hammer.

Their dreams, if they have them, can’t be terribly complex or symbolic, given how short these active phases are, says Medeiros. Octopuses are known to be problem solvers, however, so maybe dreams help their impressive, unusual brains consolidate memories and improve on tasks.

Ship ’em to Washington, D.C.!

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