Sunday 8 July 2012

Jennifer Mather: Evolutionary Pressures and Cephalopod Consciousness

Jennifer Mather   Evolutionary Pressures and Cephalopod Consciousness
Abstract: On the face of it, cephalopods are unlikely candidates for consciousness, even at a primary level.  They stem from slow, simple molluscan ancestors, but during evolution they have lost the protective shell.   Likely in the competition with bony fishes, they have instead developed a centralized brain, acute vision, complex control of arm movement and a stunning skin display system.  But unlike other non-human animals with well developed cognition, they are not social.  What would the evolutionary pressure be, then, for these animals to develop consciousness?  The answer may lie in the complexity of their near-shore marine environment.  Mobile cephalopods must search this environment to find prey, and octopuses do so with a saltatory search technique.   At the same time they are vulnerable to predators and have an array of defenses, from camouflage to false eye spots and ink release to flight, to avoid or react to them.  Yet they are mobile—octopuses move to a new home range every ten days or two weeks—so they cannot store information and responses to form automatic loops.  It may be this constant change and pressure to update that caused the cephalopods to develop a simple form of consciousness.

      Mather, J. A. (2008).  Cephalopod consciousness: Behavioral evidence.  Consciousness and Cognition, 17, 37-48
      Mather, J. A. (2010).  What might consciousness in cephalopods be like? Journal of Cosmology (special issue on consciousness)http://journalofcosmology.com/Consciousness113.html
      Philosophical background of attitudes toward and treatment of invertebrates http://research.tamucc.edu/compliance/iacuc/PDF/ILAR%20Journal.pdf#page=91
      Behavioural indicators of pain in crustacean decapods http://www.scielosp.org/scielo.php?pid=S0021-25712009000400013&script=sci_arttext
      Pain and suffering in invertebrates? http://www.vliz.be/imisdocs/publications/231732.pdf
      New evidence of animal consciousness http://postcog.ucd.ie/files/fulltext.pdf
      [See also David Edelman reference list]

Comments invited

27 comments:

  1. Constructing our world on the basis of things that aren't necessarily there: that's also a very interesting way science should be looking at the world. We always use specific stimuli to induce consciousness, what for those stimuli present but not specifically shown?

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    1. There actually has been a little of this. I don't remember the details, but someone presented illusory features to an animal--likely a vertebrate like a rat. The animal did construct the figure like we would (ie seeing the triangle). this would be a very interesting way to test the construction of a 'mind'. Would the octopus see a Kanzisa figure? I don't know.

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  2. I'm certainly not a "social consciousness" proponent, but for the "non-social" octopus there is still the "social" interaction of courtship/mating, as well as predation and predator-avoidance.

    (And whether they are conscious or not depends on whether or not they feel [not sense/detect/respond-to: *feel*] a pinch.)

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    1. Why are you not a social consciousness proponent? There does seem to be good evidence for it. I am thinking about people who grow up in very poor environments, for example the wild child that grew up with wolves. And there was a case in the states where a child was isolated and constrained in her room for years with relatively no contact at all. In kinds of cases it is hard to imagine that these people had any sort of the "feelings" that we are interested in. Without any human socialization, it is hard to imagine that any one could develop the type of "feelings" that we are interested in.

      You could argue that it was their language deficiencies which would make it difficult for them to communicate their ability to "feel". But then again, would they past the Turing test? Most likely not. So should we consider that they have no consciousness?

      My point being that we all are born with the capacity for language as well as "feeling". And whether these develop or not, in my view, has to do with socializing. These of course are just anecdotale accounts. But it just seems like there is overwhelming evidence, at least for humans, that feeling, at least in part, evolved to help navigate an ever increasingly complex social environment.

      Also how is hunting or predator avoidance social? None of these actions involved conspecifics, at least to my knowledge and how Dr. Mather explained it. Also from what I know of octopus mating, very little, I doubt it is social in any sense. There are no couples, the two octopi do their thing and then that`s it. Mommy then goes to shelter and tends her 10,000 eggs, gently caressing them and staying with them until she dies. Then two of those 10,000 survive on average. No mother or father there to socialize them. So I have to agree here with Dr. Mather that octopi exhibit no or very little social behaviour.

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    2. Yes, I don't think of the octopus (or the squid) as social just because it manages to overcome its aversion to conspecifics and mate. The squid is a little bit different, in that it hangs around in groups of animals about the same size, like what we think of as fish schools. But there's no cooperation, and they will eat smaller squid if they get them at the right disadvantage. No parental socialization, no teaching...not really social.

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    3. Pain is felt, and it's not social.

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    4. That's the trouble with that word, it has too many and too broad meanings. And there's an active debate whether inverts 'feel' pain or 'sense' nociception.

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    5. With regards to pain, isn't there the conceptualization that there is an emotional, a cognitive, and a purely sensing component to it?

      I don't know all that much about it, but if you could manipulate the "anticipation" factor through conditional learning or something and thus also manipulate the response to a same stimuli... would that show that the pain is felt rather than only sensed?

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    6. All three "components of pain" -- emotional, cognitive and sensory -- are felt. Otherwise they are not pain, just robotic detection, processing, and responding.

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  3. From that what i heard now so far about the octopus it is a nice example that certain cognitive functions might develop in different life situations depending if there is a certain need to cope with similar problems, like the raven and ToM. I never expected to think about the consciousness in cephalopods, but i mean this is why we are here right. Also, i think that following those observations wego back where and when something like the conscious experience developed during the sensorimotor interaction with the environmnent.

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    1. That's why I think they are so important, they represent a different model of at least the progression to consciousness (I find it easy to see them as having 'access' consciousness).

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  4. Dr. Mather,

    Your illustration of the cephalopod's camouflage and home-finding capacities was so striking that I don't think I will ever forget it. It will be very interesting to find out the neural mechanisms of the spatial memory in these animals, as it is clear that they have highly developed sense of where they are, were, and will be... given that we understand a lot about rodent spatial memory, it will be interesting to compare these mechanisms subserving similar functions and find out the different ways evolution has come up with to deal with a similar problem.

    Another question: I am an open water diver, where would be a good place to go to try to spot some octopi? :)

    Thank you!

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    1. Yes, I think that solving the problems of navigation is necessary for animals of different phyla and cognitive capacity. The book I read was Animal Thinking, editor Randolph Menzel and Julia Fischer, based on a Strungmann forum.

      Any place that animals are relatively protected is OK for finding octopuses. I find them in Bonaire, in the Caribbean, because the near shore is all marine park. And I find them by the garbage heaps of shells outside their homes.

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  5. Jennifer's talk was absolutely stunning!

    Her octopuses illustrated brightly the "cleverness" (if I can say so!) of evolution but it also illustrated that every single thing evolution "created" has its intinsic purposes and no detail of the relevant components of the environment is left behind.
    Evolution allows organisms to cope with their environment as a whole. The complexity of the environment an organism lives in has to be reflected in the complexity of the organism itself and especially in the complexity of its behavior.

    To come back on the argument that social factors might have enhanced the developement of human higher cognitive abilities, humans probably developed some of their cognitive abilities in response to a physical complex environment well before their empathic abilities which are probably the result of the complexity of their social environment. Actually human encephalization began well before the complexification of social interactions. That might actually be encephalization, and therefore, a slower development of human babies that influenced the complexification of human social interactions, the latter would also explain the emergence of ToM.

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    1. There's a paper on foraging strategies of one of the fruit-eating monkeys. They have to remember, like the octopuses, how to find their way ot to food and back to shelter. But they also have to remember what rain forest trees are fruiting or flowering at what time, and what cues tell them the fruit is ready...then how to get it and maybe how to compete with others for it. There's lots to learn and remember for primates, I suspect therefore that the pressures for evolution of intelligence were dual.

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  6. Dr. Mather,

    I was very surprised by the octopus' sophisticated navigation system. I was wondering if you could give us some details about how it achieves it. Does it have an ability for path integration where it integrates the vectors of the path taken and can infer the vector that will get it back home? Or does it use cue-guided/topography-guided navigation? It would seem that the octopus' sophisticated visual system would be useful in supporting the latter type of navigation.

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    1. There has been little testing of octopuses on this, just a bit by Jean Boal. However there's more on cuttlefish. In a t-maze they can use visual cues for guidance or they can use the vector (right or left turn). And it's sometimes different by sex, Crystal Alvez in Caen did that work.

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    2. Thank you, I will check out those references.

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  7. Thanks for a fascinating talk!!
    I've been thinking about whether or not the octopus chromatophore system could be under volitional control, or whether it is an engrained reflex mechanism.
    How would the octopus camouflage effect perform in a 'stimulus-free' environment, as Bjorn Brembs used to test free-will in his flies?
    If we put an octopus in a stimulus-free tank and measured the 'behaviour' of its pigments, and they turned out to show non-random patterns, would you say this is evidence of chromatophore free-will (or volitional control over pigments - possibly as some form of language as you briefly suggested), as Brembs suggested for his flies?

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    1. I think we're better off seeing it as a motor output system that has control at different levels (as we have reflexes and conscious movement). So the camouflage is pretty low-level, countershading in cuttlefish is reflexive. When you keep an octopus in the lab, it gets rather dingy, maybe the low light levels tune down the camouflage. But think of the squid that can aim a sexual display on one side of its body and an agonistic one on the other. That has to be volitional.

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    2. Considering that it seems to have been claimed earlier in the discussion that squid or octopi are not very social, it is interesting to this example of ‘volition ’ (the aim of different colours on the different sides of the squid for different goals). If this is not a reflex, it appears to indicate a social component, on one side a social aspect related to the mating ritual and on the other a defence against danger. There also seems to be a sense of volition, do all of these contribute to consciousness? Would a sense of agency be needed to qualify this volition as part of consciousness? How could we ever know if the squid has a sense of agency? Would there be any way to test this?
      Also, I found the coconut example so cool! It definitely seems to me as though there is some kind of future planning happening in that case.

      Izabo Deschênes

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  8. Thank you for this talk, it was clear to us how you were found of octopi and it just spread to me too!
    I don't want to argue against an octopus' consciousness, in fact it seems almost impossible to think that such an intelligent creature could feel nothing. Nonetheless, when you gave the example of the coconut and you said that the octopus could anticipate, I wasn't convince it was anticipation since most creatures search a refuge to sleep etc. It could just be an instinctual behavior like a bird creating its nest.

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    1. This is a beautiful example of why we need lab work as well as field observation. Yes, the alternates need to be tested.

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    2. The coconut example was quite striking! I am not sure that the octoctopus' ‘coconut-seeking’ ability could qualify as instinctual behavior though. For a given species to develop a purely instinctual behavior involving objects of a certain type (e.g. birds who use twigs in order to build their nests), individuals of that species must be in frequent contact with objects of that type at some point in its evolutionary history. Birds could not have developed their twig-gathering instinct if they seldom saw twigs (or something that looked like twigs) in their environment. So, unless octopi were in frequent contact with coconuts in their environment (or something with a similar appearance that they could recognize visually) at some point in their evolutionary history, then it seems unlikely that they developed instinctual behavior to reach for coconuts. It seems more likely that this impressive feat was the result of higher representational abilities (involving anticipation).

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    3. It's always hard to figure out where a particular piece of behaviour came from. I suspect that octopuses have a 'drive' to seek shelter. When I tested some ages ago (Marine Behaviour and Physiology 8, 285-293, 1982), they 'liked' snail shells more than clams, and they 'liked' a sizeable home with a tiny entrance. But when I went out in the wild and watched (Journal of Zoology, London, 233, 359-368, 1994), I found that wonderful homes don't lie around waiting to be occupied. So they choose a 'possible' home, clean it out with arms and water jets, and sometimes bring rocks to pile in front of a too-big entrance (that's tool use). I suspect them of having a need to seek shelter, and an ability to manipulate the possible so that it's adequate for actual shelter. Finding a coconut probably releases a lot of associations about 'good' homes. But how it 'knows' that it needs to take the shell with it for later shelter, that's a whole different story, and I don't know the answer.

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    4. In response to Alexandre and to add to Dr. Mather's comment: I am inclined to think that, as Marjorie proposed, the coconut-seeking ability could be instinctive. After all, as Dr.Mather mentioned, cephalopod's evolved from molluscan ancestors with protective shells. In this light, one could legitimately perceive the coconut-seeking ability as an adapted and modified shelter/shell seeking instinct.

      But again, whether or not a behavior is instinctive or deliberated upon, it changes nothing to the fact that that behavior can be felt OR not.

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  9. Dr. Mathiers talk was fascinating! I was particularly interested by the spatial navigation in octopuses observed through foraging patterns over several days. I was curious about the long range navigations abilities of the octopus. How far can are they able to travel for foraging and return home? Also, what type of navigational cues do the animals use to navigate foraging?

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