Friday, June 5, 2020

Global Workspace Theory Sure Isn't an Explanation for Consciousness

Neuroscientists have no credible explanations for the most important mental phenomena such as consciousness and memory. All that scientists have in this regard are some far-fetched speculations or weak theories that don't hold up to scrutiny.  Supposedly the two most popular theories of consciousness proposed by scientists are one theory called integrated information theory and another theory called global workspace theory. You can read here why integrated information theory does not work as a credible theory of consciousness.  Global workspace theory isn't any better.

The wikipedia article on global workspace theory starts out by explaining it this way:

"GWT can be explained in terms of a 'theater metaphor.' 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. The audience is not lit up—it is in the dark (i.e., unconscious) watching the play. Behind the scenes, also in the dark, are the director (executive processes), stage hands, script writers, scene designers and the like. They shape the visible activities in the bright spot, but are themselves invisible."

As a causal explanation for why a brain might be able to produce understanding or consciousness, this is a complete failure, as it does not refer to anything in the brain, but refers to some theater. At most it is some metaphor merely describing selective attention, but selective attention (or mental focus) is merely an aspect of understanding once it exists, not an explanation of consciousness or understanding.  You can't spotlight your way to consciousness. Also, there's nothing in the brain that actually corresponds physically to a spotlight. When you're thinking about something, it is not at all true that some particular region of your brain lights up like some area under a spotlight, contrary to the misleading statements and misleading visuals often given on this. Actual signal strength differences (typically far less than 1%) are no greater than we would expect from random variations.  

In an interview in Scientific American, Bernard Baars attempts to explain global workspace theory, but fails rather miserably to give a coherent explanation of how global workspace theory is anything like a theory explaining consciousness.   He is asked by the interviewer, "What is global workspace theory?" What we then get from Baars is  an answer that kind of wanders around all over the place for 11 paragraphs without giving much of any answer that anyone will be able to grasp. 

There is some mention of some swarm computing setup: "If you put a hundred crummy algorithms together and let them share hypotheses and vote on the most popular one, it turns out that very inadequate algorithms could jointly solve problems that no single one could solve." There is entirely irrelevant for any explanation of consciousness or understanding, because particular areas of the brain are not like little micro-processors running software code. There is nothing like software code that runs anywhere in the brain. 

Baar's rambling and muddled answer to the question ends like this:

"Part IV of my latest book On Consciousness: Science & Subjectivity develops GW dynamics, suggesting that conscious experiences reflect a flexible 'binding and broadcasting' function in the brain, which is able to mobilize a large, distributed collection of specialized cortical networks and processes that are not conscious by themselves. Note that the 'broadcast' phase proposed by the theory should evoke widespread adaptation, for the same reason that a fire alarm should evoke widespread responding, because the specific needs for task-relevant responders cannot be completely known ahead of time. General alarms are interpreted according to local conditions. A brain-based GW interacts with an 'audience' of highly distributed, specialized knowledge sources, which interpret the global signal in terms of local knowledge (Baars, 1988). The global signal triggers reentrant signaling, resonance is the typical activity of the cortex."
Baar's scrambled 11-paragraph answer is a complete failure as an attempt to explain how a brain could produce consciousness or understanding. Electrical signals travel around in the brain, but there is nothing like a broadcast in the brain that could explain consciousness or understanding.  And it's rather silly to be trying to use fire alarms as part of an attempt to explain consciousness or understanding. 
To understand how impotent the idea of broadcasting is to explain consciousness or understanding, let's consider the city I grew up in. When I was a boy there were in my city several very high broadcast towers that broadcasted TV signals and radio signals. Almost every house in the city had an old-fashioned TV that picked up these TV signals, and also an old-fashioned radio that picked up the old-fashioned radio signals. But none of this huge amount of broadcasting and broadcast reception resulted in the slightest bit of consciousness in any of the antennas, the television sets or the radios.  The idea of broadcasting is worthless in explaining consciousness. 
We cannot at all explain consciousness by saying that it adds up from the activity of a bunch of networks that "are not conscious by themselves."  There is no reason why the activity of a bunch of unconscious networks should add up to be a conscious reality, any more than having a house made of bricks should add up to be a wooden house.

The reality in the brain is that there are billions of cells that each emits electrical signals.  A rough analogy might be a packed stadium with 80,000 people who are each making noise during a football game.  But still you have a unified self and a unified stream of thought from a mind. There's not the slightest reason why that would emerge from the activity of billions of individual neurons, just as there's not the slightest reason why a single paragraph of speech would ever flow from the lips of 80,000 people in a stadium.

A broadcast is a stream of tokens that can give information to an agent capable of understanding who is listening to such a broadcast. But a broadcast does nothing to ever produce such an agent of understanding.  The flow of tokens during a broadcast is rather like the stream of bullets from a machine gun.  Thinking that you can broadcast your way to consciousness is as silly as thinking that you can machine-gun your way to consciousness.

Narrating an achievement legend that is groundless (something very common these days in academia), Baars makes these mostly false claims:
"Our individuality is a function of the cortex, which is now proven by brain studies to be 'the organ of consciousness.' Wilder Penfield discovered that in 1934 via open-brain surgeries in fully awake patients, who were able to talk with him and gesture."
The brain is an organ, and the cortex is not an organ, but only a small fraction of an organ. So calling the cortex "the organ of consciousness" is nonsense.  There are no brain studies showing that the cortex produces consciousness. To the contrary, we know that after hemispherectomy operations in which half of the cortex (and half of the brain) is removed and discarded, to stop very bad seizures,  people are just as conscious and just as intelligent as they were before such an operation.  And we also know from the studies of people like physician John Lorber that people have existed with very good consciousness and above-average intelligence, even though they had brains and cortexes that were almost entirely destroyed by disease. Such medical case histories debunk claims that the cortex is the source of consciousness. Of course, an operation by Penfield in which people can talk and gesture during brain surgery does absolutely nothing to establish that the brain or the cortex is the source of consciousness.  So it is wrong for Baars to be citing such a thing as evidence that Penfield discovered that consciousness comes from the cortex.

Baars has tried to suggest the idea that consciousness comes from a broadcasting of something from the cortex. But the cortex of the brain is an actually an extremely bad broadcaster.  Electrical signals in the cortex travel from one neuron to another with a very low reliability.  It has been estimated that the chance of an action potential traveling between two adjacent neurons in the cortex is below 50%, and as low as 10%.  A scientific paper says, "In the cortex, individual synapses seem to be extremely unreliable: the probability of transmitter release in response to a single action potential can be as low as 0.1 or lower." It's implausible to be saying that cortex cells that are such bad and unreliable information transmitters (such bad broadcasters) are somehow giving rise to consciousness through some kind of broadcasting effect. 
Baars has some book describing his ideas on this topic.  But I see no reason why anyone should buy such a book, because nothing that Baars states in his Scientific American interview should give us any confidence that he has any substantive explanation for how a brain could produce consciousness, thinking or understanding.  When asked about the "hard problem of consciousness" he states there is no evidence for it, which makes no sense, and is like saying there is no evidence for the problem of the origin of language or the problem of the origin of life.  

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