An Exploration of Animal Consciousness: The Intriguing Case of the Cephalopod

Every minute we spend awake, the brain is constantly receiving, processing, and organising the overwhelming amount of sensory information flooding in. Amidst that tangle of sensory input, there is a reflective, contemplating voice, an inscrutable quality that seems to differentiate us from insects and moss. We call that consciousness. Empirical studies and firsthand observations continue to beg the compelling question of whether we need to quantify an animal’s consciousness in order to ascertain how we should treat them. Precisely defining consciousness is almost impossible, as the phenomenon is famously difficult to study empirically. At the same time, understanding it in humans and animals is essential to ensuring universal welfare, although this quest comes at the risk of humbling ourselves and redefining the place that Homo sapiens occupies in relation to other species.

In an attempt to prevent anthropomorphizing species instead of understanding them, it is necessary to distinguish between consciousness and sensation. When your dog whimpers at a painful stimuli and steers clear of it in the future, he might not be forming the complex conscious perception that we observe and empathise with - his behaviour is likely a reflexive response to sensation to nerve cell endings called nociceptors, which initiate the sensation of pain. Instinct translates sensation into action, but consciousness is something much more nuanced than that.

Much of the history of the scientific reckoning with animal inner minds has been dominated by a desire to prove that the cognitive capabilities of animals are somehow second-class to our own.. Instead, as Ed Yong writes in his masterful exploration of animal senses, An Immense World, the study of animal consciousness, sensation, and experience should be “not about superiority but about diversity.” Our endeavours to discern exactly what consciousness is comes at the risk of simplifying it to measurable neurochemical processes, or expecting species that we deem as intelligent to have models of consciousness similar to our own. Yet, animals have vastly differing nervous systems, sense organs, and minds, which must be considered in a qualitative manner as we chart forward with our understanding of consciousness.

No creature better exemplifies the remarkable diversity of neurological structure and consciousness in comparison to humans than the cephalopod. The molluscan class Cephalopoda includes the squid, octopus, and cuttlefish, animals with undeniably complex nervous systems that are remarkably unlike our own. The common ancestor between humans and cephalopods likely existed 600 million years ago, equipped with a simpler nervous system lacking in a centralised brain. From there, two models of the nervous system were independently developed through convergent evolution: the chordate design seen in fish, reptiles, birds, and mammals (including us) and the “ladderlike” nervous system possessed by cephalopods. The chordate nervous system is composed of a brain attached to a cord of nerves down the spine, and while the cephalopod nervous system does have a brain, the nerves are much more decentralised, with the majority actually located in the arms instead of the brain. This structure provides the arms with a kind of autonomy unseen in mammal bodies - octopus arms are in control of basic motion, able to reach and grasp even when surgically removed. In the words of Peter Godfrey-Smith, a philosopher of science with a penchant, these creatures are “suffused with nervousness,” living “outside the usual body/brain divide.” So, what does this say about cephalopod consciousness?

Countless studies and observations have illustrated that cephalopods possess self-awareness and independent problem-solving abilities, along with the capacity for complex brain activities. Studies have indicated that they are capable of observational and spatial learning, in addition to using and manipulating tools. This research could be interpreted as indicative of cephalopod consciousness, yet, how can we quantify the neurological functioning of an animal whose perceptions and interactions with the world are so incongruent with our own? Many studies have also demonstrated that octopuses and cuttlefish are notoriously erratic in their responses to standard tests of intelligence and consciousness - perhaps demonstrating the species’ “stubbornness” to conform to the demands of the lab, or perhaps revealing a much more crucial flaw in how we study animal consciousness.

An octopus looking at its own reflection during the Mirror Recognition Test

The famed Mirror Recognition Test was developed by Gordon Gallup in the 1970s as a means of determining whether different animals possessed a degree of self-awareness - and therefore, consciousness. First, an animal is introduced to a mirror in order to become comfortable with it, and then a red mark is placed on its body, in an area that can only be viewed through the mirror. The animal “passes” if it is observed interacting with the mark on its own body. Although undoubtedly highly intelligent and self-aware, the octopus has repeatedly failed the Mirror Recognition Test. These results, in light of other extensive research that has been conducted on the animal, calls into question whether it is even possible, or necessary, to define cephalopod consciousness relative to our own. At a fundamental level, the ways in which they engage with the world are drastically different than our own. The internal processes and external experiences of a colour blind creature with photoreceptive skin, self-governing arms, and an unusually decentralised nervous system are unfathomable to the human understanding of our surroundings.

As fascinating as the scientific pondering of human and animal minds is, the real life applications of this thought-provoking field can have effects across veterinary treatment, animal rescue, rehabilitation, and research, guiding how we determine an animal’s needs and perception of its surroundings. The question of whether specific animals are conscious is still left unanswered by science, but perhaps the more important query is whether it is necessary for an animal to possess the same degree and type of sentience that we do for us to treat them with respect. In many cases, animal consciousness is entirely incomparable to human consciousness due to different sensory processing and neurological structure, yet that does not mean we need to develop means of quantifying and ranking the complexity of their minds to justify misguided and inhumane action. The words of John Searle ring true as we study animal minds and allow that research to influence our treatment of them: “I do not infer that my dog is conscious, any more than, when I came into this room, I inferred that the people present are conscious. I simply respond to them as is appropriate to conscious beings. I just treat them as conscious beings and that is that.” While the exploration of animal consciousness is an ongoing field of interest, defined by its vast and primarily uncharted waters, one can hope that human comprehension of animal minds should not be the decisive factor determining their welfare.