Cephalopod Behavior and Neurobiology: An Alternative Model for Intelligence


Dominic Sivitilli
University of Washington, USA

David H. Gire
University of Washington, USA

Understanding the fundamental constraints that shape the diversity of intelligent life on Earth will allow us to anticipate the possible forms that extraterrestrial intelligence might take. Since the nervous system first evolved, it has diverged and radiated into countless forms. Most familiar to us is the centralized nervous system of the vertebrates. Although highly morphologically conserved, this nervous system model has developed within a large range of complexity. Among the most sophisticated and cognitively complex of these forms includes that of the canids, corvids, cetaceans, and hominids.

At the other end of this divergence cephalopods evolved for hundreds of millions of years in parallel toward cognitive complexity of their own. Specifically, octopuses have demonstrated a capacity for observational learning[1], exploration, play[2], spatial learning[3], and problem solving[4]. They have also shown individual variation to the extent of personality[5] and signs of consciousness[6]. 

What has evolution done with the ancestral proto-nervous system to produce such behavioral complexity without being confined to the centralized nervous system of the vertebrates? The nervous system of the octopus is extensively diffuse, and collectively, their eight arms bear more neurons than their central nervous system[7]. Each arm is consequently highly autonomous, requiring inhibitory innervation from the central nervous system to monitor its behavior. With this configuration octopuses have outsourced much of their cognition toward their peripheral nervous system. Sensory information is therefore not integrated collectively but as discrete components, making octopuses resemble more closely a swarm intelligence than they do centralized models of intelligence. While their entire psychology has been evolving separately from our own since our phyla speciated 670 million years ago8, their cognitive capacity has come to rival that of even our most intelligent cousins. They effectively serve as a model for an alternative intelligence and hold astrobiological significance, providing insight into an alternative evolution of intelligence and suggesting possible forms extraterrestrial intelligence could take. In fact, the closest we can currently come to studying an alien intelligence is to study the octopus.

Through the study of the behavior and neurobiology of octopuses and other cephalopods, we can begin to understand the diversity that evolution could make of extraterrestrial life and intelligence. Simultaneously, those fundamental characteristics that cephalopods share with more well-known forms of intelligence, the globally conserved traits among all known forms of intelligence, will provide a general basis for what we can expect from an extraterrestrial intelligence, as well as perspective on our reflexive anthropocentric assessments such as their level of benevolence or aggression.

References:

  1. Fiorito, G., & Scotto, P. (1992). Observational learning in Octopus vulgaris. Science, 256(5056), 545-547.
  2. Mather, J. A., & Anderson, R. C. (1999). Exploration, play, and habituation in octopuses (Octopus defleini). Journal of Comparative Psychology, 113, 3.
  3. Boal, J. G., Dunham, A. W., Williams, K. T., & Hanlon, R. T. (2000). Experimental evidence for spatial learning in octopuses (Octopus bimaculoides). Journal of Comparative Psychology, 114(3), 246.
  4. Fiorito, G., von Planta, C., & Scotto, P. (1990). Problem solving ability of Octopus vulgarislamarck (Mollusca, Cephalopoda). Behavioral and neural biology, 53(2), 217-230.
  5. Mather, J. A., & Anderson, R. C. (1993). Personalities of octopuses (Octopus rubescens). Journal of Comparative Psychology, 107, 3.
  6. Mather, J. A. (2008). Cephalopod consciousness: behavioural evidence. Consciousness and Cognition, 17(1), 37-48.
  7. Mather, J. A. (2008). To boldly go where no mollusc has gone before: Personality, play, thinking, and consciousness in cephalopods. American Malacological Bulletin, 24(1), 51-58.
  8. Ayala, F. J., Rzhetsky, A., & Ayala, F. J. (1998). Origin of the metazoan phyla: molecular clocks confirm paleontological estimates. Proceedings of the National Academy of Sciences, 95(2), 606-611.
     

 

Dominic Sivitilli is a post-baccalaureate fellow of neuroengineering and graduate student of behavioral neuroscience at the University of Washington. He graduated from the University of Washington with a B.S. degree in biology and psychology. As an undergraduate, Sivitilli worked in the plant microbiology laboratory of Dr. Sharon Doty and studied microbe symbiotically promoted tolerance to arsenic conditions in host plants. He also collaborated with Dr. John Freeman at NASA Ames comparing the ability of microbes and overexpression of genes involved in molecular detoxification pathways to promote tolerance of plants to the conditions of the Martian regolith, with long-term implications for Mars colonization.

Sivitilli became interested in cephalopods while working with a Pacific red octopus and a juvenile giant Pacific octopus while at Friday Harbor Laboratories in the summer of 2013. Through subsequent research into cephalopod anatomy and behavior he began to grasp that among our most distant cousins dwelt a creature of exceptional cognitive complexity. The enigmatic behavior of octopuses proved largely resistant to explanation through behavioral models based on vertebrate psychology and prompted him to delve into neurobiology in order to understand this behavior at a mechanistic level. His current research focuses on neural mechanisms underlying chemotaxis in the octopus in order to understand decision making and behavior in an alternative and algorithmically transparent model for intelligence. This analysis will be used in developing computational and robotic systems based on this model.