What is in an octopus's mind?

Abstract

It is difficult to imagine what an animal as different from us as the octopus 'thinks', but we can make some progress. In the Umwelt or perceptual world of an octopus, what the lateralized monocular eyes perceive is not color but the plane of polarization of light. Information is processed by a bilateral brain but manipulation is done by a radially symmetrical set of eight arms. Octopuses do not self-monitor by vision. Their skin pattern system, used for excellent camouflage, is open loop. The output of the motor system of the eight arms is organized at several levels - brain, intrabrachial commissure and local brachial ganglia. Octopuses may be motivated by a combination of fear and exploration. Several actions - a head bob for motion parallax, a 'Passing Cloud' skin display to startle prey, and particularly exploration by their arms - demonstrate the presence of a controlling mind, motivated to gather information. Yet most octopuses are solitary and many are cannibalistic, so they must always be on guard, even against conspecifics. The actions of octopuses can be domain general, with flexible problem-solving strategies, enabling them to survive "by their wits" in a challenging and variable environment.