With their obtuse heads, elongated bodies, and eight tentacles, octopuses do not resemble humans whatsoever. But, according to a new University of Oregon study, we have more in common with the mollusks than meets the eye.
About 70% of an octopus’s brain is dedicated to its vision. Yet, it was only recently that scientists began to understand how these sea creatures view their underwater environment.
In this novel study, neuroscientists recorded the neural activity of an octopus’s visual system for the very first time. By observing the octopus’s neural activity in response to both light and dark spots in varying locations, the team was able to create a map of the creature’s visual field.
Interestingly, this neural activity map looks remarkably similar to what is observed in human brains. This is in spite of humans and octopuses last sharing a common ancestor approximately 500 million years ago and the marine animals’ nervous systems evolving independently afterward.
“Nobody has actually recorded from the central visual system of a cephalopod before,” said Christopher Neill, a neuroscientist at the University of Oregon.
While octopuses are not normally used as models for vision understanding, that didn’t stop the researchers from becoming intrigued with the animals’ strange brains.
Just last year, the team published a paper identifying various categories of neurons located in the octopus optic lobe. This paper, joined by the researcher’s most recent inquiry, works to provide a well-rounded picture of octopuses visual processes.
“These papers provide a nice foundation by elucidating the different types of neurons and what they respond to– two essential aspects we’d want to know to start understanding a novel visual system,” Neill explained.
In their latest study, the researchers analyzed how octopus visual system neurons responded when dark and light spots traveled across a screen. The team used fluorescent microscopy to watch the neurons’ activity as they responded and observed how these reactions differed depending on where the light and dark spots appeared.