Cuttlefish wearing 3D glasses are not to watch the latest blockbusters, but they are helping scientists better understand how the squid sees when hunting for food.
Those are findings from a study published in the journal Science Advances. Trevor Wardill, assistant professor of ecology, evolution, and behavior at the University of Minnesota, and the lead author of the study, shared with CNN that his team stuck Velcro patches on the skin of the cuttlefish.
They then fastened the 3D glasses with a red and blue filtered lens onto the Velcro on the skin. At the same time placing a screen in front of the ink tank, the researchers streamed videos of shrimp, one of their favorite foods.
“It takes a lot of time and effort to wear glasses for cuttlefish,” Wardill said.
But when these little creatures wore glasses, a miracle happened. The cuttlefish will expand its tentacles and attack the shrimp on the screen in the same way they see prey in the wild.
Stereoscopic vision refers to the ability to see with both eyes in similar but slightly different ways. Stereopsis allows people to judge distance and be truly cognitive by extracting information from the left and right eye and then letting our brain perform some complex processing. 3D glasses also use this technique to create the illusion of depth. University of Minnesota researchers led by Trevor Wardill and his colleague Rachelael Feord at the University of Cambridge wanted to check if cysts also used stereopsis to see distances – and so they built miniature 3D glass creatures.
To conduct the study, Wardill’s team from the University of Minnesota took a summer trip to the Marine Biology Laboratory in Woods Hole, Massachusetts.
There, they conducted experiments on 11 different European cuttlefish and Sepia officinalis to see how they responded to their favorite prey films.
Cuttlefish have cornea, lens, iris and retina. They can move their eyes independently of each other, which gives them a 360-degree view. Each eye moves in slightly different locations to recognize objects at a distance.
They are capable of using stereopsis – a term often used to refer to the perception of depth and three-dimensional structure obtained on the basis of visual information derived from the eyes of individuals with visual binocular individuals. normal development.
That means they can recognize the distance because their brain can explain the difference between signals coming from both eyes.
When the researchers conducted experiments with the squid wearing glasses, they found they would adjust their position relative to the screen.
“Cuttlefish are more aware of depth and distance than we can be,” Wardill said.
Researchers have successfully demonstrated that, like humans, the squid brain can calculate distances using information coming from both eyes at the same time.
However, “the squid brain is capable of using a different algorithm than it does in humans”.
The study, published in the journal Science Advances on Wednesday, concluded that cuttlefish actually use stereopsis. However, the way vertebrates, such as humans and cuttlefish use stereopsis in different ways – processing images in the brain happens in a different way. These findings can be applied to real-world technical problems.
Wardill has been studying insect vision for about 15 years. And since 2012, he has focused on the vision of cephalopods, molluscs including cuttlefish.
His laboratory work has uncovered nerve connections between the head’s brain and various body functions – for example, skin bumps called papillae, used for sense perception.
Wardill’s group was inspired by scientists at Newcastle University, who published a study in June 2019 on the eyes of cephalopods.
That research is the first time scientists have found neurons in a invertebrate that support stereoscopic vision.
“Different brains calculate stereo vision in different ways,” Wardill said. “We thought there might be something special about the eyes and vision of the mantis.”
But squid brains can do the same, which means that skills can develop in different ways in biological history, depending on the age and animals.
Creatures such as cuttlefish or mantis may seem odd, but understanding them will help us offer the most appropriate machine vision for different situations, such as drones, vacuum cleaners. Robots or security cameras.