It’s one of those questions you ask yourself every day. How do squids sleep? Some take these questions seriously. For example, researchers from the Federal University of Rio Grande do Norte, Brazil. They tell us that octopuses change color when they dream. They have an “active sleep” level and a “quiet sleep” level.
Are you dreaming?
It was published in iScience. This would indicate that octopuses might experience something similar to dreaming.
Scientists used to think that only mammals and birds had two sleep states. A REM-like sleep state has been reported in squid, a cephalopod compared to the squid. “Could we see evidence of two sleep states in octopuses?” Asked lead author Sidarta Ribeiro. ‘Octopuses have the most central nervous system of all invertebrates. They are known to have high learning ability. ‘
They recorded video footage of squids in the lab. During the “peaceful sleep” the animals were still and quiet. During “active sleep” it was a different story. The animals dynamically changed the color and texture of their fur. They also moved their eyes as their suckers and body contracted in muscle spasms. Octopuses change color while dreaming at this stage.
“This ‘active sleep’ occurs mainly after a long ‘restful sleep’. Generally longer than 6 minutes, and that has a characteristic periodicity, “says Ribeiro.
The cycle would repeat at approximately 30 to 40 minute intervals. The results have interesting implications for squid and sleep development. They also raise interesting new questions.
“The alternation of sleep states observed in the Insularis octopus seems to be quite similar to ours,” says first author and doctoral student Sylvia Medeiros. Two different sleep states developed twice independently in vertebrates and invertebrates. What are the main evolutionary pressures that shape this physiological process? “he wonders.” The independent development of cephalopods from ‘active sleep’ analogous to REM sleep in vertebrates may reflect an emergent property that is common to the centralized nervous system and that reaches a certain level of complexity. “
“If octopuses are really dreaming, they are unlikely to experience complex symbolic acts like we do. The “active sleep” in the octopus has a very short duration. Usually a few seconds to a minute. If there are any dreams going on in this state, it should be more like little video clips or even gifs ».
Do squids have nightmares? Could the dreams of octopuses be inscribed into their dynamic skin patterns? Could we learn to read your dreams by quantifying these changes? “
We want to know that too.