The octopus and the unity of consciousness

If the octopus were conscious, what would its consciousness be like? This paper investigates the structure octopus consciousness, if existent, is likely to exhibit. Presupposing that the configuration of an organism’s consciousness is correlated with that of its nervous system, it is unlikely that the structure of the sort of conscious experience that would arise from the highly decentralized octopus nervous system would bear much resemblance to those of vertebrates. In particular, octopus consciousness may not exhibit unity, which has long been assumed to be the normal or default structure of consciousness. The octopus nervous system is characterized by the following features: its three anatomically distinct components have extensive functional autonomy and little intercommunication; much of the sensory processing and motor control routines—that in vertebrates are localized in the brain—take place within the peripheral arm nervous system; and proprioception and somatotopic representation (point-for-point mapping of the body) are significantly downplayed. In this paper, I present the octopus as a highly successful biological organism in which it is plausible that the unified model of consciousness does not hold.