Do you often have nightmares and suddenly wake up scared? Is this a unique ability of human beings? As it turns out, some animals can dream too, even in a disturbing way. And we’re not talking about dogs or cats, frequent subjects of study in this regard, but about a very unusual animal: the octopus.
About two years ago, a group of US scientists observed one of these curious marine invertebrates, which they named Costello. This octopus showed behavior similar to what we usually have when we wake up from a bad dream, in experiments conducted in a New York lab over the course of a month in 2021.
The whole process was recorded on video, which shows the octopus appearing to wake up from a restful sleep and wriggle around, in a reaction that suggests the animal was suffering from some kind of sleep disorder.
At the time, the researchers published an article in the journal Direct sciencedocumenting what appears to be evidence for a two-stage sleep pattern in octopuses, classified as “active” and “quiet.”
This pattern is similar to the way humans oscillate each night between rapid eye movement sleep (REM) – the stage in which dreams occur – and non-sudden eye movement sleep (NREM).
The finding has led scientists to question whether octopuses can also dream during “active” sleep, something inconclusive in that paper, which requires further investigation.
This is because there are other possible explanations for the animal acting in the way observed. “Despite all the studies that have been done on octopuses and other cephalopods, there’s still a lot we don’t know,” said Eric Angel Ramos, a postdoctoral researcher at the University of Vermont who helped record the four videos. by Costello.
In them, the octopus is placed calmly in a tank before suddenly starting to flail its tentacles wildly. In two of these episodes, Costello also shot a jet of black ink into the water, a common defense mechanism of these animals against predators.
In an update of the investigation, reported in an as-yet-unpeer-reviewed article made available this month on the preprint server bioRxivthe authors speculate on other justifications for Costello’s behavior in those situations to which he was exposed.
According to them, “the animal could respond to a negative episodic memory or exhibit a form of parasomnia,” that is, a sleep disorder.
A scientist who was not involved in the research expressed caution about interpreting the octopus’s actions as dreams. “We don’t know enough about the neuroscience of sleep in cephalopods to tell if they dream, let alone have nightmares,” Robyn Crook, a comparative neurobiologist at San Francisco State University, told the website. living science. “And even though octopuses dream, they can dream in a completely different way than humans.”
According to her, this is not something that can be answered objectively. “It’s a very philosophical question,” said the expert, listing other possible interpretations for Costello’s behavior.
“He may have been surprised by something, as he may also be showing signs of senescence,” he suggests.
Crook pointed out that Costello’s tentacle movements seemed more like evidence of poor motor coordination, something that is associated with the final stage of life in octopuses, than anti-predator behavior.
Indeed the insular octopusthe species to which Costello belonged, lives for about 12 to 18 months – and died shortly after the recordings.
The post Seeing an octopus supposedly awakening from a nightmare first appeared in Olhar Digital.
Source: Olhar Digital