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Evolution of consciousness
M. Tintner
Friday, 25 September 2009 10:34 UTC
I’ve just been discussing the evolution of consciousness with a friend.
My assumption is that the “surround movie screen” which is (I agree with Hans) the principal content of human consciousness, has steadily evolved through animals – from v. early on in evolution. No doubt, the screen has become steadily more focussed, detailed, coloured, and multi-sensory. But, I assume, there has had to be some kind of “screen” (a somewhat distorted/flattened metaphor for the real thing) – because that screen provides an essential, integrated way to map the world around an animal, and view how things fit together and relate.
My friend, OTOH, questions whether this screen evolved before mammals:
“vertebrate animals which don’t have the visual cortex [meaning non-mammals] have an optic tectum as their primary visual center. The optic tectum responds almost exclusively to moving objects [ie, no one to my knowledge has shown much response to fixed objects]. Eg, frogs will supposedly starve to death surrounded by dozens of dead flys.
Further, the analogue of the optic tectum still exists in mammals, and is called the superior colliculus. SC cells respond mainly to motion. Furthermore, humans who have damaged visual cortices can still respond to objects as long as they are moving.
This last is called “blind sight”. They can respond accurately to moving objects, but they do not “consciously” see. They claim to be blind, and cannot “see” the objects. IOW, to not be able to view the “screen” you’ve been talking about.
What this boils down to is that animals without cortex do not have your screen, or otherwise what we think of as “conscious sight”. "
I would point out in return, that it is hard to see how lower animals can navigate the world as they do, moving between objects, (and having a moving POV of objects) – and that includes navigating mazes – if they don’t have some kind of screen/map of the immediate world.
My assumption is that even a blind worm will not just experienced fragmented, disparate, sensations of objects, for example, but will need to integrate them into tactile “maps” in order to manoeuver the objects as skillfully as it does, and drag them considerable distances to its burrow.
I’d be v. interested to hear the views of the group on all this, and esp. on what is known scientifically – and what attempts have been made to chart the evolution of consciousness in the above sense.
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Replies
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[Michel Butler]
[Yawn] Aren’t we supposed to be discussing evolution and scientific examples?
Personally, I think the focus on visual senses/sight when discussing evolution is interesting but begs the question whether we should be thinking more broadly (I’ll admit bias here, as I’m a sound/mechanical sensation researcher, but in the end they are all related) to chart the evolution of ‘consciousness’ (whatever that may be). Indeed, what is the point of trying to metaphysically define ‘consciousness’ without thinking about how the biological mechanisms behind sensation/action etc. have evolved and developed as well our current subjective top-down understanding?
[Philip Benjamin]
Most yawns are ‘infectious’ (rather inductive)?. The first ‘yawning’ human ancestor spread it around and it still persists.
Serge Patlavskiy’s proposed Rules of Consciousness are meant also for the ‘evolution’ of consciousness (a term which he or any one else cannot define or grasp except that it is ‘existent’). Michel Butler’s caution to “Remember that evolution/biology is always a bit messy and non-linear….” seems to take it for granted that by chance some proto-consciousness occurred in matter and evolved with the organic structural frame-work.
Some basic explanations are missing here:
1. Is there a ‘homology’ (unknown) for consciousness (equally unknown!!)?
2. Is there another biological axiom for the unknown consciousness also, such as “homology means descent”? Or is it ascent?
3. Is such an axiom logical if ‘structural frame work’ is prededermined by laws of genetics rather than probability laws.
4. If progress by slight variation is the rule, will the net result of ‘slight’ variation in “consciousness” related information have some kind of parallel anatomical “homology”?
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Sorry to be the stick-in-the-mud or naysayer, but I think my [yawn] still stands. Can we have some evidence please? Just the odd experiment or test in an actual biological organism or at least the real world to back up the metaphysics, otherwise I’m afraid I’ll be fast asleep in a jiffy. I may be being simple-minded here (happens a lot) but wasn’t the question in the first place to hear about interesting scientific evidence? I’m not denying models or a good discussion, they’re great, but aren’t they even better when they work with experiment?
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Dear Michael,
great input! I think though evidence is not easy. If we look at the great research on c. elegans and aplysia, we come to the obstacle that we do not know wether behavior tells us anything about the consciousness a living individual has.
You may not be aware about the lasting debate, which is a philosophical one, about consciousness being due to emergence versus consciousness having been “there” forever, everywhere (panpsychism).I think the evolutional perspective can teach us a lot for the understanding of consciousness though. If we just put aside that “big” question (emergence versus panpsychism) and rather say: maybe we can decide it one day…
Then we can start looking at possible evolutional steps. Clearly if a simple organism would be conscious the conscious experience that organism would have would be much simpler than human consciousness.I like to compare human beings with rodents (most people will agree that rodents are conscious). Comparisons like that can reveal a lot I think. In that case most senses we have are already developed. What makes the difference between rodents and humans as far as consciousness is concerned? To me most strikingly: humans have a great mind. That means conscious content is very much more “inner”. Rodents may have an inner world too, but apparently they don’t write music or invent funny things or ugly things like holocaust.
Studying rodents versus humans could reveal insights about 60 million years of evolution of consciousness.
Yours friendly
Hans -
[Michel Butler]
Sorry to be the stick-in-the-mud or naysayer, but I think my [yawn] still stands. Can we have some evidence please? Just the odd experiment or test in an actual biological organism or at least the real world to back up the metaphysics, otherwise I’m afraid I’ll be fast asleep in a jiffy. I may be being simple-minded here (happens a lot) but wasn’t the question in the first place to hear about interesting scientific evidence? I’m not denying models or a good discussion, they’re great, but aren’t they even better when they work with experiment?[Philip Benjamin]
“Yawn” is real for me rather “existent” for some? Can you say that much about “consciousness” the way it is NOT understood or NOT defined?
It is supposed to be NOT metaphysial to satisfy the requirements of basic sciences and most probably funding. It is supposed to be NOT physical either, to satisfy a new establishment in the sciences. The only “authority” and driving force behind that is Schrodinger/Heisenberg/Pauli/Carl Jung version of “rational” mysticism to the total exclusion of Neils Bohr realism.
Further Questions:
1. What are the advantags of adding a new “consciousness” terminology to already “existent” Self/‘mind’/‘psyche’/‘cognition’?
2.What is it that the UNDEFINED and UNDEFINABLE ‘consciousness’ has which none of the other “existent” terms for mind-body penomena possess?
3. Why evade the Occam’s Razor here for no specific advantage? Why is it that this term though vigorously introduced since the 1890’s, is omitted by William James?
4.He had no use of “consciousness” in the list of over 20 parameters to describe “SELF”.
5.Is it true that some “consciousnes” forums and conferences phoo phoo such questions?
6. Is it “doctrinaire” or a contemptuous rejection of a supposedly aberrant or threatening position? The only instance I can remember anybody seriously and honestly questioning some of the fundamental assumptions and axioms in this new “research field” is that by Dr. Whitehead, a couple of years ago. How so? That was mostly ignored!!
Sincerely,
Philip Benjamin
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As I see it the problem presented by tracking the ‘evolution of consciouness’ is to follow the evolutionary trail provided by fossils and artefacts (the latter mainly in the human case) so as to discover when there might have been the emergence of an ‘inner self’ (as presently being described in its sad and terrifying distortions by schizophrenics). I conjecture that such a creation of an inner self most likely occurred in the explosive enlargement of the brain in humans in the last 250,000 years. That it could have happened before then is debatable, in the light of little evidence of self-adornment or of cave painting before then. Those two activities were, I think, suggestions of the beginnings of an inner presence, carrying the notion of an inner life rather than one driven by basic drives (sex,hunger, thirst, cold, etc) and aa an immediate response to them. Evidence then points to the evolution of a modern consciousness about 50,000 -20,000 years ago.
Comments please?
John Taylor -
It’s a pity no one seems to be interested in the “movie” that is consciousness – as distinct from sentience – let alone the evolution of the movie. As soon as you do get interested, you realise that the self – the Cartesian or whichever self – watching is inseparable from the movie.
An agent’s consciousness IOW includes the awareness of the agent’s self-and-body watching at one end of a field, as well as of the surround movie at the other ends of that a field. This is essential for any agent navigating and manipulating the world.
Even a worm is surely going to have such consciousness of its self watching and moving through the field around it (even if its is a ‘blind’ movie).
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Dear John Taylor and M.Tintner:
I agree with M. that consciousness involves both the “movie” (“objective” content) and the “self” (the subject) who is watching it, and that one exists and evolves relatively to the other. There are many possible concepts of each one. In cognitive sciences the representational concept of the content and the self-referential concept of the subject are the hegemonic views.
I would be interested in a different, non-representational and non-self-referential approach: the content is the lived experience of the world, and the subject is the individual who feels the experience.
In this view, a important set of data in human evolution consists of tools made by the homo habilis. This step in human evolution can be related with Patricia Greenfield’s hypothesis (in her 1991 paper*) that a development of the motor cortex circuits that control hand movements is the origin of Broca´s area, which took control of the larynx muscles that allowed spoken language – a phenomenon that happened only in the human species.Best Regards
Alfredo
*Greenfield, P. M. (1991) Language, tools, and brain: The ontogeny and phylogeny of hierarchically organized sequential behavior. Behavioral and Brain Sciences, 14(4):531—551.
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Alfredo said “I would be interested in a different non-representational and non-self-referential approach”
I can’t resist, sorry Hans, but I have been trying to be good, but this was the perfect seguey!
I can’t offer you a non-representational approach, because at some level, the brain must represent the world in order to navigate it, but what I can offer is a system of consciousness that is not wholly representational, in the sense that the experience of the world, and the body, does not reflect directly the knowledge the brain has about the world, and how the body fits into it.
I call this the representational but partially illusory concept.
One interesting aspect of this approach is that is does not involve a cartesian theater of the mind, merely that a portion of the processing done in the mind be reflected back into the processing stream more than once.
The interesting aspect of this approach is that it is compatible with evolution, if only because it assumes that there are real evolutionary steps in building the brain, but it is controversial because it assumes that consciousness is a latecomer limited to mammals and birds, in our current understanding of evolution.
Drosophila have according to one recent article an almost equivalent form of implicit memory architecture as mice. Whether there really is so little difference as is suggested in the article as being a few synapses difference, is debateable, but implicit memory has an excellent conservation across many species.
As well, a form of memory called Reinforcement Learning as evidenced by the existence of ganglia, has been conserved since the lowly snail at least.
There is no doubt in my mind, that implicit memory exists, and that reinforcement learning exist in the humans, because there are areas such as the olfactory bulb, that seem to implement implicit memory forms that have been conserved from the earliest days, and the basal ganglia are after all still ganglia.
But what does a brain that has a minimal implicit memory and a minimal reinforcement learning system do? Is it conscious? In my own definition of consciousness I would have to say that No, it is not conscious.
Let us look at the Aplysia Snail for instance. There is evidence of a very thin layer of implicit memory at the boundary between the sensory neurons and the reinforcement learning capacity of the ganglia. The snail actually does store a minimalistic representation of the world, by remembering information such as whether it was exposed to bright light, twisted on a turntable, whether someone was interfering with the health of its syphon, or threatening its gill.
Further it goes through stages in learning such as sensitization and habituation that seem associated with implicit memory.
It is my theory that implicit memory is the most natural result of neural memory architecture, and therefore so simple to create in comparison to other types of memory that it becomes the natural defaul condition.
However in Fodors book “The Mind Doesn’t Work that Way; The Scope and Limitations of Computational Psychology” we are warned that some types of memory, specifically discrete isolatable memories, are not that simple to design, suggesting that there must be two classes of memory, the implict, and thus simplest form, and the explicit, which might be much more complex.
In fact, an attempt to understand the architectural limitations of the brain, has led me to the discovery that the design of the brain unfolds for the researcher who understands the constraints under which the brain must operate if it is to have both implicit and explicit memory.
I suspect the evolution of the brain would also make more sense if we understood the mechanisms that are necessary to design an explicit memory capability under such constraints.
Consider the limitations of the snail brain. It can do a minimal representation of the environment using implicit memory, and can instinctively react to the stimuli it experiences, to the sophistication of doing a sort of dance when meeting another snail, but does it know what it is experiencing? I would have to say no, there just isn’t enough room in its miniscule little brain for the mechanisms needed.
If we look at evolution we should see, that the first brains were simply action reaction networks that involved separate links between Senses, and Motor Neurons associated with each sense. The utility of having a Unifying implicit image of the world, within the brain, gave the lowly snail an evolutionary edge, that was conserved in later animals. But don’t ask me to support the “Consciousness” or even “Sentience” of animals like C-elegans and Aplysia, they are merely from this point of view, early steps in the development of brains, and we should not read too much into their functions.
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Graeme Smith on 31 Oct 2009 wrote:
Consider the limitations of the snail brain. It can do a minimal representation of the environment using implicit memory, and can instinctively react to the stimuli it experiences, to the sophistication of doing a sort of dance when meeting another snail, but does it know what it is experiencing? I would have to say no, there just isn’t enough room in its miniscule little brain for the mechanisms needed.[S.P.] Possession of consciousness is not dependent on possession of the brain. Mental abilities are not dependent on the brain’s size. All living creatures (including the colonies of bacteria, the protozoa and the brainless clams) possess the exemplars of consciousness which equal as to their mechanisms, so their potentialities. All living creatures are equally alive, and are equally conscious. They all are expediently evolved as mentally so physiologically. Otherwise they couldn’t be alive. Consciousness (as an ability of reducing the complex system’s entropy by processing the incoming physical signals and transforming them into the elements of subjective experience) is not exposed to evolution. This ability or is present, or is absent. Therefore, there can be no room for the antiscientific doctrine of anthropocentrism which presumes that the human’s consciousness (or consciousness as such) appeared in the result of the long process of evolution, and that the human only is endowed with reason.
Best,
Serge Patlavskiy -
Well Serge, You aren’t going to evolve a brain by ignoring its functions.
The fact is that the brain is the seat for most of the processing needed to experience our environment, so tell me how you become conscious of your environment when you don’t have a brain?
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