Octopuses Gain Consciousness

Octopus uses empty shells to hide; image courtesy of Wikimedia Commons/Nick Hobgood

Elephants cooperate to solve problems. Chimpanzees teach youngsters to make tools. Even octopusesseem to be able to plan. So should we humans really be surprised that “consciousness” probably does not only exist in us?

This privileged state of subjective awareness in fact goes well beyondHomo sapiens, according to the new Cambridge Declaration on Consciousness (pdf), which was signed last month by a group of cognitive neuroscientists, computational neuroscientists, neuroanatomists, neuropharmacologists, neurophysiologists who attended the Francis Crick Memorial Conference on Consciousness in Human and non-Human Animals at Cambridge University in the U.K.

“The weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness,” the scientists wrote. “Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.”

A 2009 study showed that some octopuses collect coconut shells to use as portable shelters—an example of tool use, according to the researchers. Other research has documented sophisticated spatial navigation and memory. Anecdotal reports from researchers, such as Jennifer Mather, describe watching octopuses in the wild make errands to collect just the right number of rocks to narrow the opening to a desired den. And laboratory experiments show a distinct change in behavior when octopuses are kept in tanks that do not have enough enrichment objects to keep them stimulated.

But, as the authors of the new declaration noted, many nerve networks involved in “attentiveness, sleep and decision making appear to have arisen in evolution as early as invertebrate radiation, being evident in insects and cephalopod mollusks (e.g. octopus).”

Even emotions (or, according to the declaration, their “neural substrates”) are not dependent on an animal having particular brain structures, such as our cortex, after all. In fact, many other neural regions are activated when we emote and “are also critically important for generating emotional behaviors in animals,” the scientists noted.

“Exactly how organized brain matter gives rise to images and sounds, lust and hate, memories, dreams and plans, remains unclear,” Christof Koch, chief science officer at the Allen Institute of Brain Science, and co-presenter of the new declaration, recently wrote in the Huffington Post. And although brain structures, such as the cerebral cortex, in mammals seem to be highly conserved evolutionarily, Koch noted, other organisms, such as birds and cephalopods force us to reexamine other neural components of consciousness. “The challenge that remains is to understand how the whispering of nerve cells, interconnected by thousands of gossamer threads (their axons), give rise to any one conscious sensation,” he wrote.

Via: "Scientific American"