It is well-known octopuses change their color while they sleep. A new study reveals the color changes characterize two distinct sleep states, "active sleep" and "quiet sleep". The findings shed new light on the evolution of sleep.
A new map of the octopus visual system classifies different types of neurons in a part of the brain dedicated to vision, shedding new light on the evolution of the brain and visual systems in a more broad sense.
By implanting electrodes and monitoring data, researchers have successfully captured the brain activity of freely moving octopuses. The recorded brain activity could solve numerous questions about octopus behaviors including movement, cognition, and learning abilities.