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

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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.

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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.”

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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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