The limits of neuroscience

I’ve been looking for good counterpoints to John Gray’s mind-altering book Straw Dogs since reading it a couple of years ago. Raymond Tallis provides one in his formidable critique of “neuroscientism” in The New Atlantis.

Here’s a drop from the bucket:

A good place to begin understanding why consciousness is not strictly reducible to the material is in looking at consciousness of material objects — that is, straightforward perception. Perception as it is experienced by human beings is the explicit sense of being aware of something material other than oneself. Consider your awareness of a glass sitting on a table near you. Light reflects from the glass, enters your eyes, and triggers activity in your visual pathways. The standard neuroscientific account says that your perception of the glass is the result of, or just is, this neural activity. There is a chain of causes and effects connecting the glass with the neural activity in your brain that is entirely compatible with, as in [Daniel] Dennett’s words, “the same physical principles, laws, and raw materials that suffice” to explain everything else in the material universe.

Unfortunately for neuroscientism, the inward causal path explains how the light gets into your brain but not how it results in a gaze that looks out. The inward causal path does not deliver your awareness of the glass as an item explicitly separate from you — as over there with respect to yourself, who is over here. This aspect of consciousness is known as intentionality (which is not to be confused with intentions). Intentionality designates the way that we are conscious of something, and that the contents of our consciousness are thus about something; and, in the case of human consciousness, that we are conscious of it as something other than ourselves. But there is nothing in the activity of the visual cortex, consisting of nerve impulses that are no more than material events in a material object, which could make that activity be about the things that you see. In other words, in intentionality we have something fundamental about consciousness that is left unexplained by the neurological account.

Here’s the bucket.

12 thoughts on “The limits of neuroscience

  1. Dave Snowden

    You might want to read Mark Rowland’s “The New Science of the Mind” MIT 2010. Its a good summary of a body of material around embodied, embedded, enacted and extended (the 4Es) of consciousness. Its not necessary to agree with his conclusion to get benefit from the summaries and links. He critiques “Cartesian Cognitive Science” as per your comments above, and implicitly its a criticism of what I sometimes call the “New Calvenists” such as Dawkins and the other “meme/there is no free will” types.


    Quite eloquent. But not convincing. The fact that we can not yet look at an ecephalogram, and tell what a person feels and thinks does not mean that it is not possible, or that conscience is not a direct result of brain’s electro-chemical activity. Philosophers can discuss these “fundamental questions” for as long as they want, and in the mean time engineers are already building gadgets that allow wearer to play the game of pong by just thinking about where the paddle should go. These things are very crude at the moment, but they will get better, and the day will come when it will be possible to see/understand/copy “the person” by simply taking a detailed enough set of measurements. Will it be soon? No. Will it happen? Yes, definitely.

    PS. For the folks that don’t mind their dose of philosophy delivered in a lighter way, I highly recommend watching both “Ghost in the shell” movies (it’s an interesting look at what might happen when mind merges with the machine).

  3. Seth Finkelstein

    It won’t matter, but the error is pretty obvious.

    “There is nothing about a sensor that makes the software run. Therefore, the software doesn’t exist or is unknowable. And I’ve never heard of self-modifying programs to boot”.

    Your body is a connections of wires and levers and springs, not a divine essence. A MACHINE. A marvelous machine, but not a mystical creation.

    Your brain is similarly a complicated system of switches. Many of them, wired in awesome complexity, but ultimately A COMPUTER.

    In the same way the evolution was disturbing to many because it denies humans are divine, neurology is similarly disturbing because it is a modern version of denying humans are divine.

  4. Kelly Roberts

    Consciousness is strictly reducible to the brain in the very obvious sense that, if you are hit in the back of the head with a crowbar, you lose consciousness. Just because neuroscience can’t explain all aspects of consciousness doesn’t mean all aspect of consciousness don’t derive from the brain.

    On the other hand, declarations about the imminent triumph of AI and denials of mental states (love, pain, angst) are themselves quasi-religious.

    We are not divine. But we are unique.

  5. Nick Carr

    Well put, Kelly.

    But, just for the sake of argument: if someone gouges out your eyes, you’ll lose your sight. Does that mean that sight is strictly reducible to the eyeball?

  6. Kelly Roberts

    No, but I would say that both visual perception and consciousness are strictly reducible to the central nervous system.

    As Searle, I believe the mysteries of consciousness are purely biological. But I don’t know that we will ever solve them. We have the key, but the door is locked from the outside.

  7. Seth Finkelstein

    We’ve only had modern science itself for a few centuries, and brain science for even less. For heaven’s sake, just because a difficult problem might not be solved in your lifetime is hardly a reason to think it’ll never get solved. For a very simplistic example, look at how long it was that people pondered the mysteries of flight, until the invention of the airplane.

    Imagine going back to ancient Greece and trying to explain aeronautics to philosophers. I can just hear it – “No, my foolish friend, flight cannot be reduced to the mere motion of air, for if a man garbs himself in wings like an eagle, no matter how fast he flaps his arms in imitation, he does not fly. The gods must give some ability to birds that will forever be beyond our understanding.”

  8. Nick Carr

    just because a difficult problem might not be solved in your lifetime is hardly a reason to think it’ll never get solved.

    There’s a difference between thinking it will never get solved and thinking it may never get solved. I would think that the workings of consciousness will get clearer as time goes by, but I don’t assume that what we’ll end up discovering will bear much resemblance to what we assume today.

    We’re still at the wing-flapping stage.

  9. Seth Finkelstein

    Yes, but there’s no reason to think that if civilization and science continue (which is not a certainty, granted, but an assumption for discussion here), that it won’t be solved eventually, and in a way “strictly reducible to the material”. My core point is that the objections given in the post above are so trivial, very much shallow statements that the writer obviously thinks are a killer argument. It reminds me strongly of a sort of fallacious argument against evolution. One which runs roughly that evolution can’t be true, because the Second Law Of Thermodynamics states entropy always increases but evolution says complex structures can arise from simpler ones (and thus, gotcha, obviously a wizard – God – must be behind it all). People making that class of argument are merely trying to find justification against being “no more than material events in a material object”.

  10. Stewart Dinnage

    @Dave Snowden

    “such as Dawkins and the other “meme/there is no free will” types.”

    Can you direct me to where Dawkins supports that there is no free will?

    For me one point that seems often ignored in these seemingly philosophical debates is the potential for infinite complexity. I have no evidence that these things we study (such as the electrochemical interactions in the brain or the amount of timespace, blackholes or anything else in the universe) are infinite or infinitely complex, nor have I seen evidence that they are definitely not.

    Once you factor in the possibility of infinite complexity, materialism and the no free will meme as you put it, seem a bit silly to my mind. Perhaps my finite/material/free will less brain just can’t handle it?

    As someone else said though, Kant, Baudrillard and a bajjilion (technical term) other philosophers have clearly been at this one for a while…

    As for the bash me on the head and I lose conciousness argument. I believe people having a limb amputated without anaesthetics often passed out too, so perhaps the nervous system is a better place to consider conciousness.

    Of course if James Lovelock’s Gaia hypothesis, are ever proven correct (which would contradict Dawkins position) the whole darn life on earth would act as a single organism. In which case we’re just a few cell communicating with some other cells, all trying to understand something singular but even more complex than what’s going on in our own nucleus.

    My head hurts now!

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