Project Reason is a 501(c)(3) nonprofit foundation devoted to spreading scientific knowledge and secular values in society. The foundation draws on the talents of prominent and creative thinkers in a wide range of disciplines to encourage critical thinking and erode the influence of dogmatism, superstition, and bigotry in our world.
At what point in evolution did consciousness originally emerge from neural activities in animal organisms?
“Evolution of consciousness:
The increasing willingness of scientists to discuss consciousness in animals has also fostered renewed speculation about the evolution of consciousness. Ginsburg & Jablonka (2007a, b ) attribute a primitive form of ‘overall sensation’ as a by-product of even the simplest nerve nets in animals, but they argue that it is only as these states became harnessed during evolutionary time to learning and motivation that they acquired the functional properties of ‘basic consciousness’. They propose that this transition occurred in invertebrates, perhaps as early as the Cambrian. Cabanac et al. (2009) also refer to the motivational properties of consciousness as key to understanding its evolution. Citing evidence that amphibians lack certain physiological, anatomical, and behavioral markers of emotion — e.g., in response to handling frogs do not show a slowing of heart rate (aka emotional tachycardia) — they locate the key transition in the origin of the Amniote vertebrates, the lineage that includes reptiles, birds, and mammals. Edelman & Seth (2009) survey evidence for consciousness in birds and cephalopods, and they conclude that while the evidence for cephalopod consciousness is suggestive, it is not as good as the strong evidence for avian consciousness.”
* Cabanac, Michel, Arnaud J. Cabanac, and André Parent. “The Emergence of Consciousness in Phylogeny.” Behavioral Brain Research 198, no. 2 (2009): 267-272. (PDF)
“ABSTRACT: The brains of animals show chemical, anatomical, and functional differences, such as dopamine production and structure of sleep, between Amniota and older groups. In addition, play behavior, capacity to acquire taste aversion, sensory pleasure in decision making, and expression of emotional tachycardia and fever started also to be displayed by Amniota, suggesting that the brain may have began to work differently in early Amniota than in Lissamphibia and earlier vertebrates. Thus we propose that emotion, and more broadly speaking consciousness, emerged in the evolutionary line among the early Amniota. We also propose that consciousness is characterized by a common mental pathway that uses pleasure, or its counterpart displeasure, as a means to optimize behavior.”
Problem:
“Are there signs of consciousness before Amniotes? Slugs displayed aversion learning, Lymnaeas and terrestrial mollusks displayed operant conditioning of escape behavior. Yet the most striking performance was that of cephalopods who were described as playing and as being able to learn by looking only.
These observations lead to three possibilities:
* The first is that play and these other apparently signs of consciousness, actually do not necessitate consciousness. True consciousness emerged actually with Amniotes.
* Another possibility is that elements of consciousness already showed byMollusks and Fish are the results of convergence only, as there is a clearcut absence of any sign of consciousness among Amphibians. Thus, these early elements did not evolved to the full four-dimensional consciousness displayed in Amniotes, possibly by lack of a large enough nervous system.
* The last possibility, as suggested by Rial et al., is that consciousness emerged quantitatively in phylogeny as early as Mollusks, but became exploded only with Amniotes.
If that were the case, then there would remain to find an explanation to the total absence of any sign of consciousness inAmphibians early late entails implicitly that the processwasmore likely to have been qualitative rather than quantitative.” (p. 271)
As for the possibility/probability of consciousness in cephalopods, see:
* Edelman, David B., and Anil K. Seth. “Animal Consciousness: A Synthetic Approach.” Trends in Neuroscience 9 (2009): 476-484. (PDF)
If we look at the evolution of our nervous system, we see that a decision making web first surrounded the digestive tract of multicellular organisms coordinating the activities of cells to cooperate in harmony. We then see a bulge of decision making capacity at the mouth end where choices are made on what to eat or reject. As additional senses (feeling, hearing and sight) are developed the capacity to MAP and interact with our environment improved.
Consciousness is a function emerging from locating ones “self” in that mapping.
Obviously greater brain power significantly improves the quality of consciousness, but the emergent property retains it’s original function, that of equipping us to interact with the environment exterior to our bodies. All of the decisions on our internal workings simply do not show up as consciousness.
I don’t think consciousness “emerged.” Rather, it has always been present in the same way that space-time has been present. The development of nervous systems eventually reached to point where self-consciousness appeared as an emergent phenomenon. In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”
‘In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”’
Disagree burt. Visible light is electromagnetic radiation that humans can see, but why should we assume it was not present before the eye evolved? After the eye and consciousness emerged, we decided what to label it.
In a (limited) analogy, the tree still falls in the forest although no human may be there to ‘see’ it.
I think this is the clear difference between essentialism and existentialism. The essentialist believes consciousness is a priori and the existentialist believes consciousness emerged.
‘In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”’
Disagree burt. Visible light is electromagnetic radiation that humans can see, but why should we assume it was not present before the eye evolved? After the eye and consciousness emerged, we decided what to label it.
In a (limited) analogy, the tree still falls in the forest although no human may be there to ‘see’ it.
I think this is the clear difference between essentialism and existentialism. The essentialist believes consciousness is a priori and the existentialist believes consciousness emerged.
We know electromagnetic radiation was present before eyes evolved to see it. On a dark night look up at the sky. Some of the light you see left its source before the ‘Cambrian explosion’ - before eyes and consciousness had evolved. It has been travelling all those hundreds of million or billions of light years. An so, yes, it existed before eyes or consciousness. No doubt about that.
The idea that consciousness is an essential part of the universe or a corollary of the working out of the laws of nature like space and time is interesting but is supported by no scientific evidence whatsoever and may be essentially untestable.
All the evidence available points to consciousness emerging as a product of the evolution of complex nervous systems. By ‘consciousness’ I do not mean just ‘self-consciousness’ as opposed to some posited ‘unitary’ and ‘a priori consciousness’ experienced in meditative states, NDEs or after strokes or other brain trauma. I mean all consciousness. What is experienced during meditative states and after strokes etc is what is left after ‘I” is subtracted. It is a lower level background sort of awareness and can be explained in terms of neuronal function just as self-consciousness can. It is just background to ordinary everyday consciousness that we are not usually tuned into. What else could it be? Why posit ‘a priori-ness’ to explain it? There is no need to and no evidence supporting it. As far as I can discern, the only reason for positing it is to allow a toe-hold for mysticism, or worse, religion.
We continue to discuss this. I think burt’s hypothesis is derived from logical consideration of what might exist without distinctions. Evidence is not required to construct a hypothesis. The hypothesis can come from mathematics or logic. The evidence comes at the testing stage. While burt has not yet come up with a method of testing his hypothesis such that it could be falsified, he’s not in a significantly different position than Einstein was when he first posited his theories of relativity. The hypothesis comes from the logical process - now let the testing begin. Burt can correct me if I’m wrong about this.
Die fröhliche Wissenschaft (Rob) - 24 December 2011 07:20 AM
Avogadro’s number - 24 December 2011 06:05 AM
‘In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”’
Disagree burt. Visible light is electromagnetic radiation that humans can see, but why should we assume it was not present before the eye evolved? After the eye and consciousness emerged, we decided what to label it.
In a (limited) analogy, the tree still falls in the forest although no human may be there to ‘see’ it.
I think this is the clear difference between essentialism and existentialism. The essentialist believes consciousness is a priori and the existentialist believes consciousness emerged.
We know electromagnetic radiation was present before eyes evolved to see it. On a dark night look up at the sky. Some of the light you see left its source before the ‘Cambrian explosion’ - before eyes and consciousness had evolved. It has been travelling all those hundreds of millions or billions of light years. An so, yes, it existed before eyes or consciousness. No doubt about that.
The idea that consciousness is an essential part of the universe or a corollary of the working out of the laws of nature like space and time is interesting but is supported by no scientific evidence whatsoever and may be essentially untestable.
All the evidence available points to consciousness emerging as a product of the evolution of complex nervous systems. By ‘consciousness’ I do not mean just ‘self-consciousness’ as opposed to some posited ‘unitary’ and ‘a priori consciousness’ experienced in meditative states, NDEs or after strokes or other brain trauma. I mean all consciousness. What is experienced during meditative states and after strokes etc is what is left after ‘I” is subtracted. It is a lower level background sort of awareness that we are not usually tuned into and can be explained in terms of neuronal function just as self-consciousness can. It is just background to ordinary everyday consciousness. What else could it be? Why posit ‘a priori-ness’ to explain it? There is no need to and no evidence supporting it. As far as I can discern, the only reason for positing it is to allow a toe-hold for mysticism, or worse, religion.
We continue to discuss this. I think burt hypothesis is derived from logical consideration of what might exist without distinctions. Evidence is not required to construct a hypothesis. The hypothesis can come from mathematics or logic. The evidence comes at the testing stage. While burt has not yet come up with a method of testing his hypothesis such that it could be falsified, he’s not in a significantly different position than Einstein was when he first posited his theories of relativity. The hypothesis comes from the logical process - now let the testing begin. Burt can correct me if I’m wrong about this.
Bruce. You are right. It’s about testability. But the notion of a priori consciousness has been around for a long time - way before Einstein. Einstein’s theory was testable. Indeed, tests were implicit in Einstein’s theory. For example, if things were as Einstein supposed, then light should bend in the direction of massive bodies. Such bending was observed and the theory was supported. The a priori ‘theory’ (such as it is) contains no such implicit testablility. That is the difference between Einstein’s theory and notions of ‘a priori-ness’. Implicit testability is the first sign of a possibly good theory. Testability is a real problem for essentialists.
To posit an untestable theory is about as much use as positing gods. It just adds an extra layer of inexplicable and unnecessay complexity and we end up with a greatly more difficult problem than we had in the first place.. I would like someone to tell me how a priori-ness might be testable. (And, please, don’t rely on first person accounts of ‘unitary’ consciousness. Dennet at al and science are able and prepared to deal with those.)
In the meantime, it is difficult ot see any reason why one should not continue to follow and align oneself with the scientific journey of Dennet, Hofstadter, Damasio, Deutsch et al who, in relation to consciousness, I talked about at length with Burt in my post at http://www.project-reason.org/forum/viewreply/263189/ . Avagadro speaks to the same spirit in his OP. At the moment the truth, as far as we know it, lies in the existentialist or, as Burt refers to them in his paper, the ‘computational functionalist’ camp.
It should be remembered that philosophy, as penetrating as it can be, is not science. No one expects philosophy to provide anwsers in physics or chemistry. Consciousness is a physical, chemical, biological phenomenon that only science can explain. Philosophy may need to explain what scientific answers mean - that is, what the moral/ethical implications are, but only science can tell us what gravity,neurons, consciousness etc actually are and what they do. To that extent, we jettison pure philosophy and religion and mysticism and rely on science because only science has shown itself capable of providing answers to questions about the physical/phenomenal world. What is left for philosophy is ethics/morals and musings on ontology and epistemology. Science is generally humbly content, for the moment, to leave those to philosophy.
I don’t think consciousness “emerged.” Rather, it has always been present in the same way that space-time has been present. The development of nervous systems eventually reached to point where self-consciousness appeared as an emergent phenomenon. In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”
SERIOUSLY?
Consciousness is a function of the brain. No brain, no consciousness.
proof? go into any home for the aged and watch their consciousness degrade as brain function deteriorates.
Pretending there is some sort of universal non-brain needed consciousness is an extraordinary claim that requires extraordinary proof, and there is not even a shred of evidence to back the thing up, it’s pure fantasy.
I don’t think consciousness “emerged.” Rather, it has always been present in the same way that space-time has been present. The development of nervous systems eventually reached to point where self-consciousness appeared as an emergent phenomenon. In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”
SERIOUSLY?
Consciousness is a function of the brain. No brain, no consciousness.
proof? go into any home for the aged and watch their consciousness degrade as brain function deteriorates.
Pretending there is some sort of universal non-brain needed consciousness is an extraordinary claim that requires extraordinary proof, and there is not even a shred of evidence to back the thing up, it’s pure fantasy.
Not at all. It’s a minority position at the moment in consciousness studies, but has some pretty strong supporters and I think that as time goes on it will come to be a paradigmatic assumption. You’re making the usual error in thinking of the word “consciousness” as automatically implying “self-consciousness” or “awareness,” the latter two of which certainly are a result of brain processes. But the intensity of your reaction might tell you something about your self.
BURT: I don’t think consciousness “emerged.” Rather, it has always been present in the same way that space-time has been present. The development of nervous systems eventually reached to point where self-consciousness appeared as an emergent phenomenon. In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”
This is a fascinating hypothesis. I can’t think of any reason why it might not POSSIBLY be true.
BURT: I don’t think consciousness “emerged.” Rather, it has always been present in the same way that space-time has been present. The development of nervous systems eventually reached to point where self-consciousness appeared as an emergent phenomenon. In a (limited) analogy, there has always been electromagnetic radiation, but it wasn’t until the evolution of the eye that there was “light.”
This is a fascinating hypothesis. I can’t think of any reason why it might not POSSIBLY be true.
As I have said to Burt before, it IS a fascinating hypothesis. And there is no reason why it cannot POSSIBLY be true just as there is no reason why just about anything cannot POSSIBLY be true. But that’s not the point. Science is about hypotheses, testablity, evidence (or the lack thereof), criticism, modifying hypotheses, testing….until a model is arrived at that not only describes a phenomenon like gravity or consciousness but also makes testable predictions. The model stands until in is found not to work. And then the process must continue and so ad infinitum. That is how science works and how knowledge advances. Pure thought has never been enough. If it had, the ancients would have gone much further in explaining the phenomenal world. Thought must yeild testability and rise or fall on the results of testing. There is no evidence that there are two types of consciousness - the everyday sort and another a priori sort. And no testable hypothesis (as far as I know) that could yield evidence to support such an idea.
I’m sure Burt, as a man of science, does not mind discussing with others what they see as potential difficulties with a hypothesis. It’s not about, or shouldn’t be about, garnering supporters to shore up one’s position. It’s about doing science - conjecturing, criticising, testing… That process, the scientific method and its outcomes, can be the only real basis for supporting a hypothesis. The number of people attracted to a hypothesis for emotional/religious reasons is irrelevant. I think the ball is again in the court of the ‘a priories’. So far, the balls Chalmers et al have returned have been nothing but risible, unforced errors. (Although, admittedly, those balls have been in relation to so called ‘qualia’. But the issue of ‘qualia’ is central to the so called ‘hard problem’ of consciousness that some philosophers are enamoured of. With advances by the ‘computational functionalist’ camp ‘qualia’ will evaporate like the ether and phlogiston.)
I’m waiting for someone to come up with a hypothesis for a priori consciousness that is testable. In some ways I think it would be kinda nice if Burt’s idea was correct. In the meantime, I’ll continue to look to theories that can promote action in the field and in the lab. After all, that’s where all the action seems to happen and, without the results of which, Nobel Prizes in the physical sciences are generally not won. And yes, consciousness is a huge physical, chemical and biological problem. But, as much as some would like to think otherwise, it is not more than that.
The reason consciousness evolved is that there’s nobody observing the universes in which consciousness didn’t evolve. The fact that we’re here to reflect implies that consciousness must have evolved.
Why “evolved”, why not just popped up out of thin air? Well, it must be easier to get evolution with conscious systems as a byproduct than conscious systems from scratch.
Anyway, about a more important subject. Now that I’m out of the can, there’s gonna be hell to pay. The Earth is going to bleed. You cannot stop me any more than you can stop a moving freight train. Word to the wise, don’t wander onto my rail-track.
The reason consciousness evolved is that there’s nobody observing the universes in which consciousness didn’t evolve.
The “only when observed” interpretation of various strange particle behaviors in quantum physics is a theory of God. It depends on having a “first observer” to get the universe started. I think we can do better than duck back at the same fallacy that let people believe in a god moving the planets to present a god moving subatomic particles.
