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Can octopuses dream? A new study hints at a tantalizing answer

by Claire Cameron
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Octopuses are among the most fascinating — and most intelligent — creatures on our planet.

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These curious cephalopods are so smart, they have caused some scientists to question where the boundaries lie between consciousness, as we understand it in humans, and intelligence in other animals.

Octopuses have been shown to have personalities, the capacity for emotion, the ability to play, as well as expert problem-solving skills...

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Now, scientists think they’ve discovered an uncannily human-like ability in the common octopus (Octopus Vulgaris) that’s to do with how these creatures sleep.

Octopuses have two distinct, cyclical sleep states — active sleep and quiet sleep
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During quiet sleep, octopuses turn pale, their eyes close tight, and their skin color and texture remain uniform.

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But during active sleep, the octopuses’ skin dramatically changes color, and their eyes move in a way analogous to rapid-eye-movement (REM) sleep in humans.

Active sleep has never been observed before in an octopus. And it has important implications for evolution.
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Sidarta Ribeiro led the new study. He tells Inverse that once a creature’s brain reaches a certain level of complexity, they may need cyclical sleep to properly integrate information across the brain, learn, and form memories.

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“Dreaming is probably something that has been going on in mammals for many, many years,” Ribeiro says, referring to the evolution of mammals. “The octopus is probably dreaming as well.”

In humans, REM sleep is when we dream. If octopuses also experience something like REM sleep — the active sleep state — then it is possible they might dream, too.

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This idea is still “far-fetched,” he says, and more research is needed before scientists can tease out whether an octopus can dream or not.

Read more stories about animals here.
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