We all know what consciousness is. We can tell when we’re awake, when we’re thinking, when we’re pondering the universe, but can anyone really explain the nature of this perception? Or even what separates conscious thought from subconscious thought?
Historically any debate over the nature of consciousness has fallen to philosophers and religious scholars rather than scientists. However, as our understanding of the brain increases so do the number of scientists willing and able to tackle this tricky subject.
What is consciousness?
A good analogy of consciousness is explained here based on work by Giulio Tononi. Imagine the difference between the image of an apple to your brain and a digital camera. The raw image is the same whether on a camera screen or in your head. The camera treats each pixel independently and doesn’t recognise an object. Your brain, however, will identify the object, that it is an apple and that it is food. Here, the camera can be seen as ‘unconscious’ and the brain as ‘conscious’.
The bigger the better?
This example works as a simple analogy of how the brain processes information, but doesn’t explain the heightened consciousness of a human in comparison to say a mouse. Some people believe that brain size is linked with consciousness. A human brain contains roughly 86 billion neurons whereas a mouse brain contains only 75 million (over a thousand times less). A person might then argue that it is because our brains are bigger and contain more nerve cells that we can form more complex thoughts. While this may hold to a certain extent, it still doesn’t really explain how consciousness arises.
To explain why brain size isn’t the only thing that matters, we need to consider our brain in terms of the different structures/areas it consists of and not just as a single entity. The human cerebellum at the base of the brain contains roughly 70 billion neurons, whereas the cerebral cortex at the top of the brain contains roughly 16 billion. If you cut off a bit of your cerebellum (don’t try this at home) then you may walk a bit lopsided, but you would still be able to form conscious thoughts. If however, you decided to cut off a bit of your cortex, the outer-most folds of the brain, your conscious thought would be severely diminished and your life drastically impacted. So it seems that the number of brain cells we have doesn’t necessarily relate to conscious thought.
Linking information
As a general rule the more primal areas of the brain, such as the brain stem and cerebellum act a bit like the camera. Like the camera, they are purely responsible for receiving individual pieces of information from our sensory organs and don’t care for linking this information together. As you move higher up the brain, links form between different aspects of our sensory experiences. This linking begins in mid-brain structures (such as the thalamus) then these links are made more intricate and permanent in the cerebrum.
Tononi believes that it is this linking of information that is the basis for consciousness. As cells become more interlinked, information can be combined more readily and therefore the essence of complicated thought can be explained. The more possible links between cells, the more possible combinations there are and therefore a greater number of ‘thoughts’ are possible.
There may be more neurons in the cerebellum than the cerebrum, but because they are not as extensively linked to each other, they cannot form as complicated thoughts as the cerebrum. When information is relayed upwards from the cerebellum in the brain, it is passed to neurons that have more connections and can therefore make more abstract links. Perhaps a neuron responsible for telling the colour red links with a neuron responsible for the representation of a round object, giving you the notion of a red apple. If you multiply this process up a couple of times, cells soon hold a lot of combined information – smell, taste, colour etc. all come together to create your representation of the apple.
Too much connectivity
So it’s the number of connections that matter? The more connections the better? Well no, sadly it’s not quite that simple. The cells at the higher levels need to be highly interconnected but if all the cells in the brain were too interconnected then you would really be back to square one, where the whole system is either on or off. All the cells fire, or none of them do. Here, you lose all specific information and your brain doesn’t know whether it is red or round or anything, it just knows there’s something. Because along with your red apple cells, all your blue cells will fire, all your bicycle cells will fire and so on, meaning you’ll get no clear information about the apple whatsoever.
The key is that cells at the basic level need to be focused and not have their message conflicted by other information. They then pass their message up to a more connected cell that combines it with other information before passing it up a level, and so on and so forth. Now we have an entity that can build up complicated information from small bits. According to Tononi it is the ability to combine lots of information efficiently that yields the ability to analyse abstract concepts and thus gives us ‘consciousness’.
How do we become unconscious?
The true test of how good a theory of consciousness this is is whether it can also explain a loss of consciousness. Tononi believes that unconsciousness is brought on when the system becomes fragmented and connectivity in the brain decreases. This is exactly what seems to happen when in a deep sleep (when we don’t dream) or under general anaesthetic. Normally when awake and alert, fast activity can be found all over the brain and signals can be passed between areas. When we go into a deep sleep however, the brain moves to a state where signals cannot easily pass between different areas. Tononi believes that the cells temporarily shut off their connections with each other in order to rest and recuperate, therefore losing interconnectivity and associated higher thought processes.
While it may seem a far reach to suggest that consciousness is purely a state of high interconnectivity, what Tononi has done is to present the beginnings of a tangible scientific theory, backed by evidence that suggests interconnectivity is crucial for higher brain power. The question of why we can form conscious thoughts is more of a philosophical one but the scientific view seems to be that it is a fundamental property of our brains. The evolution of man has led our brains to become highly efficient at processing complex information, giving us a vast repertoire of possible thoughts. This repertoire has expanded to such an extent that we can now debate our very existence and purpose. Whatever you believe about the reasons behind consciousness, however, scientists are beginning to have their say about what rules may govern consciousness in the brain.
Post by: Oliver Freeman @ojfreeman
This article completely fails to address, let alone answer, the stated question: “what is consciousness?” It flirts with some of the phenomenology of brain activity and consciousness. We know that the brain must be involved, that it must process and integrate sensory information. But so what? The question was not – “what is the relationship between the phenomenology of consciousness and brain activity?”
The assumption here seems to be that consciousness is simply an epiphenomenon of brain activity, which is one view amongst many. In a way it is the path of least resistance for physical scientists, which is why philosophers don’t take scientists seriously as philosophers. Scientists seem unconcerned by their own assumptions and presuppositions when it comes to consciousness.
An amoeba can identify an object it comes into contact with as food or not food. Indeed single celled organism are able to respond to their environment in a variety of ways – tropism is hardly consciousness though, is it? So that analogy breaks down, unless the author is suggesting that an amoeba is conscious.
Rather than pretending that these observations and the (untested) inferences which some of the more speculative scientists draw from them are an explanation of what consciousness *is*, the author would have been better to settle for the less grandiose task of describing what consciousness begins to look like from the outside. It looks like a camera that includes pattern recognition – though that is not how we experience seeing from the inside. Describing the externally visible phenomena of consciousness is far from a complete project – the research described has merely scratched the surface – and it is only half the problem of what consciousness is.
Excellent response. Science has no answers to the question of consciousness. I suspect consciousness develops because we form ideas and symbols through systems such as language, logic and mathematics. In ‘lower’ animals there may be a primitive consciousness, a basic sense of ‘self’, but there is no capacity to form ideas.
Consciousness is also very closely linked to free will, which is expressed through our rational faculties. For instance, If I toss a coin, I can make my choice based on the result of the toss, detaching my actions entirely from any internal or environmental ‘causal chains’, as the outcome is purely a chance result, and my action follows from that only.
Was Plato right all along? Is the material world just clothing for the real world? Does materialism/empiricism blind us to the essential ‘purposefulness’ of phenomena? I mean that every object, however small, is defined not by its physical ‘essence’ which we cannot determine, but it’s properties – charge, spin, mass, etc. While these are physical properties, they are also labels attached to the ‘thing-itself’, and not what it actually is.
Consciousness is also the medium through which a subject perceives an object. Until we come up with a way of separating objects from our subjective POV, we must allow consciousness a central role in any attempt to define the external material world, which leads us to the paradox at the heart of epistomology.
Hi Geoff,
No. It’s not that science has no answer to the question of consciousness. I don’t think that is the case either. But this article does not address the problem. However a number of scientists – and Antonio Damasio and Thomas Metzinger are my favourites do address the problem of what consciousness is. They seek to go beyond describing what is does, and to explain how it works (which is a step further along).
You, like the author of the article, also seem more concerned with the phenomenology of consciousness (in quite a scientific way), i.e. what it does, than with the question of what it is or how it workd.
I think Plato was answered quite comprehensively by Kant, and I don’t understand why anyone gets excited about Plato’s answers to his own questions in this day and age when his insights are so obviously outmoded and anachronistic.
‘Plato is famous for his theory of forms – The world of the Forms is eternal and unchanging. Time and change belong only to the lower sensory world. “Time is a moving image of Eternity”.’
http://en.wikipedia.org/wiki/Metaphysics
Still seems fresh to me. In physics, especially cosmology and quantum physics, the questions arise whether our physical laws transcend space and time. Nobody has an answer to that one.
Neuroscience, like all good science, is absolutely empirical. But consciousness is not an empirical phenomenon. Subjectivity is something only ‘I’ experience. You might be an automaton, but I know am not. You can’t prove you are not an automaton, and you can’t prove that I am one.
It is this internal quality of the mind, that places it beyond objective analysis. The experience and knowledge of self is a priori, as Kant said. To the subject, all things are phenomena, whether mental or physical. In fact the distinction is academic. We cannot distinguish between real sensory perceptions and artificial ones, because we are forever trapped inside our nervous system. The world we think we see is constructed in and by our imagination, from a reality utterly beyond our true understanding.
The issue if time is tied to consciousness in important ways. Since our senses perceive sights, sounds, smells and tastes via receptors which pass information up the chain of neural circuits, the information often arrives out of sync and must be processed back into order. Additionally, we are always “conscious” of the world as it existed in the past, rather than the instantaneous present- granted the awareness we possess is only milliseconds behind but nonetheless our awareness is of the recent past.
What really bothers me its how our free will works,our capability of make random decisions because,if our brain works based on chemical reactions between our neurons,the idea that it gives to me is that the brain is programed therefore,its predictble,but its not!In mine humble opinion,conciousness its something beyond our knowlege and by that i mean it is what we can’t perceive or detect.I think it do not works based on atoms or some especific wavelenght of light wich are the things that compose the universe organized in the 4 dimensions.In short,i think we are too limited to study our conciesness that is,in some way,so far from us.
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The direction of things in general should change as the notion of a subject directing brain processes is found to be false.
Hi All,
Thank you very much for your comments – I’ll try to respond to the common themes.
Jayarava, let me start by agreeing with you that this theory is only scratching the surface of trying to understand the basis for consciousness. This should not be used to attack this theory however; as scientists we accept this and enjoy the possibility of more questions. To us, nothing is ever answered completely, and this is what excites us. My final paragraph says ‘…what Tononi has done is to present the beginnings of a tangible scientific theory’ so this point had been addressed.
Your assumption that this theory is untested in relation to consciousness is not entirely correct I’m afraid. For example, Tononi has carried out experiments using transcranial magnetic stimulation to induce activity in the human brain whilst awake or asleep. The findings show that the induced activity can propagate around the brain whilst awake whereas whilst asleep, activity stays largely isolated and cannot propagate to different areas of the brain. He argues that this lack of propagation supports the connectivity theory. Once again, please don’t take away that this experiment categorically proves his point and this is a shut-book case – there is much more work to be done. There will always be more work to be done in scientific research.
As for your view that this only explains how the brain processes information, that is true also but the view provided at the end of the article is that consciousness may just be an advanced form of information processing and could simply be down to the physical architecture of our brain. I appreciate this view does not sit well with religious people and similarly, religious views continue to collide with scientific views on many topics. I’m interested by your comment that philosophers take other philosophers more seriously than scientists and I’m sure that is the case. I’d say that the reverse is also true and I don’t think we will ever see eye-to-eye on this. There is a difference in mindset when it comes to a philosophical analysis and a scientific one and I won’t try to convert your thinking.
Geoff, as for your view that ‘science has no answer to the question of consciousness’ I would say that science seeks predominantly to explain HOW things are the way they are, not WHY. Philosophy seems to me to be a discipline all about why things are the way they are and this is what your comment addresses. Science does not predominantly focus on this aspect and prefers to show how things work through the scientific method. I’d refer you to my previously discussed points about why your views that ‘consciousness is not an empirical phenomenon’ conflict with my scientific view. The scientific rationale which you seem to agree with when you say, ‘We cannot distinguish between real sensory perceptions and artificial ones, because we are forever trapped inside our nervous system.’
A final point from me on Jayarava’s amoeba retort. I think here you should follow through my reasoning once more, particularly the section on ‘Linking Information’. When describing how an amoeba recognises food you are describing a simple reflexive signalling process. The amoeba will detect a chemical, and navigate towards/away from it based on simple signalling. A nervous system correlate of this could be a spinal reflex in the human – finger detects heat, message is sent up to spine which relays a message straight back, contracting muscles to move hand. This is a very simple neural circuit with few links to other circuits – hence non-conscious. The mere recognition of food was NOT an argument for a conscious being but an example of an aspect one link might represent.
Thanks for your time and comments,
Olly
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I have been attracted to this website as I have the puzzling question on my mind too.
Am I the result of very precisely orchestrated interacting chemical reactions, a fine mazed system of chemical connectivity, or is this fine system inside me just a gateway through which something divine can interact with the world around me?
No I am not religious, nor am I here to ‘sell’ that thought, I just can’t believe my highest thoughts and reflections are the result of a very fine and complex organic computer called ‘my brain’. The only result I obtain by selfreflection is that something ‘divine’ is put inside, not because I necessarily want to believe I am divine, no, it’s just that I can’t form understanding that free will, thoughts, direction of thoughts and so forth are the result of organic material.
It’s a truely magical thing consciousness, but at this moment of my life (43 years) I tend to think that something has to be put inside that system.
The cruel thought came up that at the same time somebody in a less developed place on Earth isn’t at all occupied with this while begging for food or dedicating his or her day to find useful parts in a huge pile of waste.
Or people we call ‘less intelligent’…it that pure back luck by raw nature that those persons have less developed levels of consciousness?
It’s a strange inconsistent product a human being, don’t you think so?
It’s coming close to perfection, and it’s truely amazing to see a daughter grow up with developing thoughts… with all respect for millions of years of evolution, I find it divine, consciousness, it’s fluid, it’s continuous, without interuption when awoke.
Fine to know I have 86 billion neurons (not being sarcastic about that finding at all, I find it amazing we know it) forming the most fantastic reality interface which ever came into existance but isn’t our brain like Excel?
Finely mazed, lots of possibilities, but something has to get hold of that system and drive it, occupy it is my belief. Well, this issue which will remain unanswered for me may be, but I hope to find opinions on the internet!
Ciao Ciao!
Just food for thought Patrick regarding free will. I believe we do have some sort of free will, but not really. For example, when making a quick easy decision, there is a very rapid process of neurons firing off, but more importantly various inhibitory process in which one choice will rule out. “Should I order the healthy salad, or the cheeseburger?” Well maybe I know I should get the salad, but certain parts of my brain that want that reward might actually inhibit the logical parts and the cheeseburger wins out. (This has been studied extensively and is a similar process to swarms of bees picking a new home.)
Ok so now I’m mad at myself for eating the burger, and this emotion/memory might make the salad win the battle of my brain next time.
I know this is certainly over-simplified and I don’t mean to imply we are robots who can only do what our brains tell us. It’s a known fact that our environment and our interactions with it can alter the connections in the brain. For example if a child spends most of his childhood practicing and playing basketball, the parts of the brain involved in that are going to develop more. So in a way we can manipulate this.
Just to push a little further, what about people with Down’s Syndrome, Autism, Parkinson’s Disease, Tourette’s… Do you think they are choosing to be like that of free will? Of course not. I myself have ADHD and I can assure you firsthand that what I want to do does not always match up with what I end up doing. It’s a highly frustrating thing, and people with more severe conditions pacting their brain chemistry, I would argue, have even less freedom to do what they want.
Just food for thought
Hi Both,
Thanks for your comments.
You raise some very interesting points Patrick. I think a lot of people, myself included, struggle to fully accept that consciousness can be ‘hard-wired’ into our brains; that it is purely a result of our brain development. We long to be able to say that we are in control and have ‘free will’ and choice of our own destiny.
Justaspaz’s points on free will are very good and I agree. I don’t really think we have free will at all, or at least not much of it. We seem to be driven by our primal desires, just like Justaspaz’s burger vs salad analogy. I think we humans have a huge desire to explain things. We can’t accept that we don’t know how something works. That’s why we have scientists, philosophers etc. When there isn’t sufficient scientific backing for an idea we will fill that with our own thoughts and premonitions. Much like religious theories for the change in weather of times gone by or now, our discussions over consciousness.
I believe ‘free will’ is largely a man-made idea that we have described out of comfort. There must be a point to us being here? We like to believe we have control over all our decisions but most of them are driven by our primal desires. I’m also very interested in Justaspaz’s point on neurological diseases. He will understand far more than myself how ADHD affects his decision making and what this means for the idea that he has a divine centre to him so he can drive his own decisions.
You might be interested to read another article by a colleague of mine – http://thebrainbank.scienceblog.com/2012/06/22/blame-it-on-the-brain-can-you-be-held-legally-responsible-for-your-brain/ . Her article explores whether criminals who are mentally ill can really be held responsible for their actions. It seems that a fault in your brain can cause decision making to go awry and thus, this leads to believe that consciousness is governed by the intrinsic properties of the brain.
Thanks for the interesting discussion,
Olly
I had been reading about stilling the chatter in my brain and experiencing consciousness. Now that I can experience uncluttered consciousness for short periods of time, I find that there is no clear definition for what is actually happening when I do this. I guess I’ll need to think about it some more.
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We do know that there must be a physiological basis for consciousness because general anesthetics, as well as mood altering, and psycho-mimetic drugs, certainly exist. However, we have access only to the content of consciousness but not to consciousness itself. We do not yet know the right questions to ask.