Editor's Blog
Consciousness is the “hard problem” in mind science: explaining how the astonishing private world of consciousness emerges from neuronal activity. Recent research using EEG (brain-wave sensing) and fMRI (functional magnetic resonance imaging) measurements by Steven Laureys of the University of Liege offers evidence for the “global workspace theory,” and may also offer clues to the “hard problem” of how patterns of electrical activity give rise to our complex internal lives.
The global workspace model of consciousness, proposed by Bernard Baars, an Affiliated Research Fellow of The Neurosciences Institute in San Diego, California, proposes that perceptions below the threshold of consciousness are processed in relatively small, local areas of the brain. Broadcasting this pre-conscious information to the global workspace — a network of neural regions — results in conscious experience.
One way to think about Dr. Baars’ global workspace is to use a “theater” metaphor – but not the notion of a dualistic “Cartesian theater” (which assumes someone is viewing the theater) which is criticized by philosopher Daniel Dennett and others. In the theater of consciousness, a spotlight of selective attention shines a bright spot on stage. The bright spot reveals the contents of consciousness, actors moving in and out, making speeches or interacting with each other. Behind the scenes, also in the dark, are the director (executive processes), stagehands, script writers, scene designers and so forth. They shape the visible activities in the bright spot, but are themselves invisible. Baars’ theater is not located in a single place in the mind but distributed throughout it, nor is there a viewer distinct from what is being viewed.
Dr. Laureys’ recent EEG and fMRI work may be starting to probe beyond the so-called “easy” question. Laureys is board-certified in neurology and palliative and end-of-life medicine as well as invited professor at the Collège Belgique (Belgian Royal Academy of Sciences) and chair of the “European Neurological Society Subcommittee on Coma and Disorders of Consciousness.” Laureys’s team predicted that the activity of the default mode network (DMN, a region of the brain’s global workspace) should be greatest in healthy volunteers and in people with locked-in-syndrome, who may be fully conscious but can only move their eyes, while patients in a vegetative state or in a coma should have even less activity in the DMN.
To prove this theory, Laureys’ team scanned the brains of 14 people with brain damage and 14 healthy volunteers using fMRI. They showed that DMN activity dropped exponentially starting with healthy volunteers right down to those in a vegetative state. “The difference between minimally conscious and vegetative state is not easy to make on the bedside, and four times out of 10 we may get it wrong,” says Laureys. He conjectures that a person’s DMN may one day be used as a medical diagnostic procedure. “I’m predicting those with a higher level of DMN activity will be the ones who will recover from their coma, or vegetative states, or minimally conscious states,” he says.
The difference between minimally conscious and vegetative state is not easy to make on the bedside, and four times out of 10 we may get it wrong.
Philosophers David Chalmers at the Australian National University in Canberra, points out that “consciousness” is an ambiguous term since it can refer to a variety of phenomena. “Each of these phenomena needs to be explained, but some are easier to explain than others,” says Chalmers. “At the start, it is useful to divide the associated problems of consciousness into ‘hard’ and ‘easy’ problems. The easy problems of consciousness are those that seem directly susceptible to the standard methods of cognitive science, whereby a phenomenon is explained in terms of computational or neural mechanisms. The hard problems are those that seem to resist those methods.” Here’s David Chalmers on consciousness:
A recent University of California at Irvine course on consciousness examines these ideas and key players like Chalmers and Dennett in some depth. While the easy problem looks at correlations between brain activity and different states of consciousness — something that the global workspace theory is beginning to elucidate — the elusive hard problem of how these patterns of electrical activity could ever give rise to our subjectivity may never be fully solved. Dr. Laureys’ correlation of DMN activity to patients in a coma or vegetative state starts to show how the electrical patterns of the brain relate to “conscious” and “pre-conscious” states according to the global workspace theory, but doesn’t really come close to accounting for the richness of our inner lives.
13 Comments
I think that calling David Chalmers a ‘dualist’ is a bit misleading. He’s not saying that consciousness is a totally separate layer that has no connection to the physical. He’s only saying that the sum of all neural behaviours (as far as we understand them) doesn’t automatically generate consciousness.
What a confused interview!
Kuhn (the interviewer) referred to claims that “consciousness is an illusion – doesn’t really exist” without any indication of what was meant by the word. Cross-purpose discussion ensued and wasted a lot of time.
Then came the zombies.
It’s no wonder Chalmers thinks that evolutionary explanations of consciousness don’t hold water. Since he believes that p-zombies make sense and could theoretically exist, he already believes that consciousness is completely unnecessary for functioning humans. Therefore, no explanation for natural selection development of consciousness in an animal will ever make sense to him.
I wondered why Chalmers was so free with his use of “god” and a creation metaphor. Looks like this video comes from Kuhn’s Closer To Truth series, focusing on “Cosmos, Consciousness and God”. Two confused people sharing different confusions.
The video did prompt me to go and look at another video with Kuhn interviewing Chalmers on the subject of immortality of the soul. Chalmers described his personal journey to dualism as having searched for all possible ways to marry objective science with subjective experience, and having found none that satisfied him, he looked for systematic reasons why this might be and concluded that there is an unbridgeable gulf between them, i.e. “there are systematic reasons why no purely physical theory will ever give you consciousness. It will always be an objective theory, objective functions. None of that ever gives you subjective experience.”
From that he further concludes that there must be some immaterial as-yet-unknown property of which consciousness is made. He speculates that it might even be some fundamental property of consciousness that is attached to fundamental particles along with mass and charge…
In summary, Chalmers has concluded that consciousness must be made up of some not-objectively-measurable consciousness essence. And he believes that this assumption is the most profitable line of reasoning to follow for further consciousness studies.
I think Chalmers has confused himself into accepting some complete thought-stoppers.
Sadly, I agree with Virge. I’ve watched this video three times now in an effort to comprehend Chalmers, and am left with the impression that I’ve simply listened to a confused and intoxicated ramble. I would have much preferred to listen to a member of Laureys’ team. To me it appears they are at least working on an understanding that will lead to constructive progress.
I don’t mean to debase Chalmers’ approach to understanding ‘conscience’, but for us to get a better handle on it and learn how to effectively manipulate/stimulate it (for the revival of coma patients, etc.) we need a construct that we can work with. That’s not to say such a construct or understanding won’t later be overturned by a more refined or revolutionary understanding. Perhaps it’ll even be Chalmers who champions that refinement later on.
In the mean time, qualifying consciousness as a mysterious gift from the ‘great ether’ is not helping. Just my 2 cents.
Although this all functions fairly well as a model to describe brain processes and their interaction; which would go a long way solve the problem of ‘mind’ or awareness. It is still held back though by the fact that it can only describe the mind in mechanistic terms. The problem with consciousness itself can only be resolved (in my humble opinion) till science finds a clear way to distinguish and describe the qualia of conscious experience and how it comes about.
I respectfully disagree with your (as well as Virge’s) analysis of the piece of video. I know that what he says sounds confusing on the surface, but what’s to blame is actually the limited scope of the documentary format. (These kinds of problems generally rely on the wider, slower formats of books which are a much more sensible way to dissect the data). He is forced into the position where he has to assume the listener to be at least basically versed in the premises of consciousness studies; this includes the problem of other minds and qualia. I would agree that the personal conclusions he draws are questionable (but then again if we concern ourselves with that we’ll get stuck debating his personal life and not the issue at hand), but the rest of his statements are quite well worked out and stable arguments. The big confusion here actually lies in how the article tries to link the philosophy of mind with neuroscience, which at this moment in time are still on vastly different planes.
I agree that studying of neurons is not enough to explain conciousness. Operation system consists of blocks and layers for doing different things like working with internet protocols and so on. Studying hardware or wetware not going to show that internal structures.
As for whether conciousness real or not it’s look like philosophical wordplay. like whether mathematical formulas exists before mathematician discovered them, or in broader sense is information real or not. For example Roger Penrose thinks that mathematics is real and exists without us knowing it.
I have to agree with Virge and Viva–I believe that dualism is a non-sequitor or at least a show-stopper. “Dualism of the gaps”, respect to Dawkins. A computational and experimental approach is the only fruitful method we currently have so I say stick with it.
Of all the current dualists I respect Chalmers the most… he at least tries to address his thoughts in a rational way. Sadly he’s gathered a following of creationists and theists desperate to deny materialism… even though Chalmers himself is an atheist.
The problem dualists seem to hit on is what most people would call “failure of imagination”. They can’t conceive of a completely material and computational brain therefore it can’t exist. The Chinese Room problem is, to me, a glaring example of this.
Chinese Room Problem: All we’re really left with is an example of a data-processing room that isn’t even within the scope of complexity necessary to perform the tasks (translating Chinese perfectly) that Searle proposes. As to his question “where is the consciousness?” it would have to be “the room is what is conscious”–given that it has abilities ascribed to it.
Dualists want a line drawn in the sand but are unable to give a good answer as to exactly where that line should be. And neuroscience keeps pushing the boundaries to the point it’s almost silly to imagine a line exists where materialism stops.
I agree that the documentary format leaves people like Chalmers without the full panoply of tools he needs to make his point. People like Chalmers makes the “not-objectively-measurable” claim not just because of dualism, per se, but also because of the lessons he has learned from the physicists he works with. Not-objectively-measurable processes exist in nature, namely the quantum state evolution process scholastically characterized by the Schrodinger equation. Chalmers alludes to the fact that our mental processes make use of non-computability, like that required in the processing of human metaphorical language. Therefor, and for many other reasons not covered in this interview (see Penrose), the argument goes, the generation of qualia is non-computable and not-objectively-measurable. Therefor, like the dualism inherent in the Copenhagen Interpretation of quantum mechanics, the generation of qualia can indeed be (computably) separate from the physical processes we now identify as “mental” processes. Is, like Penrose implies, the conscious experience a quantum mechanical phenomenon? If so, then that would certainly support mind-brain dualism since most neurophenomena are currently described in terms of classical physics and chemistry.
Nice article, fascinated by the work they are doing.
Good video as well, learnt a little more about my consciousness =]
The question is not “Are we Zeroing In on the Hard Problem…”, but
“Are we _still_ Zeroing In on the Hard Problem of Explaining Consciousness?”, or preferably “Why Are we still Zeroing In?”. We don’t get it computationally, biologically or neurologically. The root of it, I think, is evaluating the power and complexity of our own consciousness. If it were simpler, we would have modeled it computationally decades ago, and would understand it from replication. But no; even today’s most powerful supercomputers aren’t capable or running something similar to a generalist analyzer problem solver that would turn insights on consciousness.
I tend to think qualia and/or subjective experience is a result of the emergent property of the brain. These properties of consciousness are aspects of the emergent system and are in fact emergent properties themselves.
Although I know little about quantum theory, I’d suggest that the relationship of subjective experience or consciousness to objective physical processes is exactly that subjective. Quantum phenomena is quantifiable but perhaps not through the immediate mechanism of subjective thought, or consciousness, rather through objective extrapolation and measurement of the phenomena. In modeling quantum mechanics we follow the same general procedure as with quantifiable information. We identify the simplest elements and create a scaffolding of logically identifiable properties, or theorems.
Given the subjective scope from which an individual identifies their existence it seems that consciousness is a very difficult problem. It is limited by the scope of the observer in my opinion. Yet through quantifiable interpolation we will be able to discover common properties of consciousness that follow a definitive and direct link to the individual parts. A puzzle not put together does not create a picture and so qualia is not separate from the mechanical process. Dualism is the temptation to leap a gap that you must build a bridge to cross.
I tend to think qualia and/or subjective experience is a result of the emergent property of the brain. These properties of consciousness are aspects of the emergent system and are in fact emergent properties themselves.
Although I know little about quantum theory, I’d suggest that the relationship of subjective experience or consciousness to objective physical processes is exactly that subjective. Quantum phenomena is quantifiable but perhaps not through the immediate mechanism of subjective thought, or consciousness, rather through objective extrapolation and measurement of the phenomena. In modeling quantum mechanics we follow the same general procedure as with quantifiable information. We identify the simplest elements and create a scaffolding of logically identifiable properties, or theorems.
Given the subjective scope from which an individual identifies their existence it seems that consciousness is a very difficult problem. It is limited by the scope of the observer in my opinion. Yet through quantifiable interpolation we will be able to discover common properties of consciousness that follow a definitive and direct link to the individual parts. A puzzle not put together does not create a picture and so qualia is not separate from the mechanical process. Dualism is the temptation to leap a gap that you must build a bridge to cross.
I think philosophical zombies do exist. Not perfectly unconscious ambulatory zombies, but people who are less than conscious.
The model I envision for consciousness is that of a monitoring program, running in the background of our computer, the brain. The more attention we pay (priority given) to this monitoring program, the higher our level of self awareness. Our ability to be self aware depends largely on the intensity of current external stimuli, levels of residual emotion, and the distractions of playing scenarios past and future. Reduce these factors and our circuitry can then look inward and examine our immediate thought status and find that we are aware of ourselves.
People who live on the edge of survival, those in constant pain or who fight each day for scraps of food don’t have the time or energy for self examination – these are your zombies. And we all are zombies to the degree that we are not fully conscious.