Sometimes science is fun and sometimes it is just plain adorable. A University of Minnesota-led research team equipped cuttlefish with little 3D glasses to test their eyesight and the end result is too cute for words.
What the interesting experiment found was that cuttlefish use stereopsis to perceive depth just like humans do. The researchers were particularly interested in how cuttlefish perceived depth in order to hunt effectively.
In the study, the team trained cuttlefish to wear 3D glasses and strike at offset images of two walking shrimp. The researchers sought to determine whether the cuttlefish were comparing images between the left and the right eye to gather information about the distance to their prey.
This process is called stereopsis, and it is how humans determine depth. “How the cuttlefish reacted to the disparities clearly establishes that cuttlefish use stereopsis when hunting,” said Trevor Wardill, assistant professor at the Department of Ecology, Evolution, and Behavior in the College of Biological Sciences.
“When only one eye could see the shrimp, meaning stereopsis was not possible, the animals took longer to position themselves correctly. When both eyes could see the shrimp, meaning they utilized stereopsis, it allowed cuttlefish to make faster decisions when attacking. This can make all the difference in catching a meal."
There was one area where the cuttlefish were different than humans. They could successfully determine the distance from anti-correlated stimulus, something humans are not good at.
“While cuttlefish have similar eyes to humans, their brains are significantly different,” said Paloma Gonzalez-Bellido, assistant professor at the Department of Ecology, Evolution, and Behavior in the College of Biological Sciences.
“We know that cuttlefish brains aren’t segmented like humans. They do not seem to have a single part of the brain — like our occipital lobe — dedicated to processing vision. Our research shows there must be an area in their brain that compares the images from a cuttlefish’s left and right eye and computes their differences.”