This octopuses they sleep but they can also dream. This is the result of a study conducted by a group of scientists that showed that these animals carry r.Physiological reactions very similar to what humans have while sleeping when they dream
Just like humans, octopuses transition between two stages of sleep: a silent stage and an active stage, which is similar to REM sleep in mammals. But could this mean that octopuses are dreaming?
When octopuses sleep periods of restful sleep are interrupted by short bursts of frenetic activity.. His arms and eyes tremble, his breathing quickens, and his skin glows with vibrant colors. All this can be seen in the video below:
Now, researchers at the Okinawa Institute of Science and Technology (OIST), in collaboration with the University of Washington, have taken a closer look at brain activity and skin pattern in octopuses.octopus lake) They found that they closely resembled the neural activity and behavior pattern of the skin during this active sleep period and when the animal was awake.
This type of wake-like activity also occurs in mammals during the Rapid Eye Movement (REM) phase of sleep, the phase in which most dreams occur.
activity winds during deep soil
Octopus during peaceful sleep goal It looks completely immobile. butThis total inactivity is interrupted approximately every hour periods of sleep that show activity similar to wakefulness (active sleep).
Study published June 28 Naturehighlights the striking similarities between octopus and human sleep behavior and provides fascinating insights into the origin and function of sleep.
“All animals seem to be asleep, even simple animals like jellyfish and fruit flies. But for a long time Only vertebrates were thought to oscillate between two different sleep stages.said lead author Professor Sam Reiter of OIST.
“The fact that two-stage sleep evolved independently in creatures like octopuses with large brain structures but with completely different brain structures from vertebrates is a general feature of complex cognition, having an active, sleep-like wakefulness stage,” says Leenoy Meshulam of the University of Washington.
to start itScientists have confirmed whether octopuses really sleep during this active period.. Therefore, they tested how the animals responded to a physical stimulus and discovered that during both the calm and active stages of sleep they needed a stronger stimulus to respond compared to when they were awake. The team also found that if the octopuses are prevented or interrupted from sleeping during active sleep, they enter active sleep earlier and more often.
“This compensatory behavior determines that the active phase is an essential stage of sleep that is essential for octopuses to function properly,” said Aditi Pophale, co-author and doctoral student at OIST.
Perceived sleep waves
The researchers also studied the brain activity of the octopuses while they were awake and asleep. During peaceful sleep, Scientists have observed characteristic brain waves that closely resemble certain waveforms called sleep spindles. observed during non-REM sleep in mammalian brains.
Although the exact function of these waves is not known, even in humans, scientists they believe they help consolidate memories. Using a state-of-the-art microscope, the researchers determined that these waves are produced in areas of the octopus brain associated with learning and memory. these waves potentially perform a similar function to what they do in humans.
Approximately Octopuses entered an active sleep phase for about one minute every hour. At this stage, the brain activity of octopuses was very similar to brain activity while awake, much like REM sleep in humans.
examine the skin
The research group also caught and analyzed the changing skin patterns of octopuses when awake and asleep in ultra-high 8K resolution.
“By shooting at such high resolution, we can see how each pigment cell behaves to create an overall pattern on the skin,” said Professor Meshulam. “This can help us build simple skin patterns models to understand the general behavioral principles of sleep and wake patterns.”
When octopuses are awake, they control thousands of tiny pigment cells in their skin. creating a wide range of different patterns. They use these patterns to camouflage in different environments, alert predators, and communicate with each other. During active sleep, scientists reported that octopuses display the same skin patterns.
Octopuses may remember waking life by changing their skin pigment.
These similarities between active sleep and wake states could be explained by several reasons, the scientists said. One possibility is that the octopuses are studying their skin patterns to improve their camouflage or simply retain their pigment cells.
Remember what you did while you were awake while you were sleeping
However Another, more suggestive possibility is that octopuses remember and learn from their experiences while awake. like hunting or hiding from a predator, and while they sleep they would reactivate the skin pattern associated with each of these experiences. In other words, they may be doing something akin to dreaming.
“While people can verbally report what kind of dream they had after waking up, The pattern on the skin of octopuses serves as a visual indicator of brain activity during sleep.said Professor Reiter.
We do not currently know which of these explanations might be correct. We are very interested in doing more research.”
Reference work: https://www.nature.com/articles/s41586-023-06203-4
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