The Frontal Cortex

Physics, Neuroscience and Mystery

Posted by Jonah Lehrer on March 14, 2007
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What’s the biggest philosophical difference between neuroscientists and physicists?* I think neuroscientists are more averse to discussions of mystery and the limits of knowledge. They’ve spent so much time convincing the public that there is no soul – the ghost is just a side-effect of our vibrating machinery – that they are unwilling to let some immaterial presence back in.

Physicists, on the other hand, strike me as much more willing to confess their ignorance. Perhaps this epistemic modesty is just a result of time: physics is a much older field than neuroscience. Perhaps it’s just a result of the strange discoveries of the 20th century: the multiple dimensions of string theory, the invisibility of dark matter, the stubborn chasm separating Einstein and quantum mechanics. Or perhaps it’s simply a result of temperment. Perhaps physicists are simply more prone to philosophizing, more willing to ponder the metaphysical implications of their physical equations.

Take, for example, this paragraph from a recent article on dark matter:

But now has come the metaphorical morning after, and with it a sobering realization: Maybe the universe isn’t simple enough for dummies like us humans. Maybe it’s not just our powers of perception that aren’t up to the task but also our powers of conception. Extraordinary claims like the dawn of a new universe might require extraordinary evidence, but what if that evidence has to be literally beyond the ordinary? Astronomers now realize that dark matter probably involves matter that is nonbaryonic. And whatever it is that dark energy involves, we know it’s not “normal,” either. In that case, maybe this next round of evidence will have to be not only beyond anything we know but also beyond anything we know how to know. hat possibility always gnaws at scientists — what Perlmutter calls “that sense of tentativeness, that we have gotten so far based on so little.” Cosmologists in particular have had to confront that possibility throughout the birth of their science.

In my experience, neuroscientists are much less likely than physicists to indulge in these sorts of mysterian musings. They are much less likely to concede that some questions are beyond the bounds of human knowledge. It’s only a matter of time, neuroscientists assure us, until consciousness is solved, and our subjective experience is reduced into a few neural networks in the PFC.

Is this neuroscientific confidence justified? Or is it just the brash braggadocio of a young science? Why do we have more faith in our microscopes than in our telescopes?

*Pardon the gross generalizations. I do realize that both fields encompass a vast range of researchers and types of inquiry. I’m just hoping to spur a discussion.

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  1. #1 Steve Silberman
    March 14, 2007

    It’s an excellent point, Jonah, and brilliantly stated:

    Why do we have more faith in our microscopes than in our telescopes?

    I think part of the situation is that the current state of physics depends on huge barely-ponderables like multiple simultaneous universes, time moving in both directions, and so on; whereas similarly awe-inspiring concepts in neurology — when does neural activity become what we call consciousness or a “soul”? — are still relegated to the margins, because they don’t seem essential for, say, curing Alzheimer’s disease. The book I referenced in a post a couple of weeks ago, Train Your Mind, Change Your Brain, about the intersection of neuroplasticity and Buddhism, raised these issues as huge open questions, but a huge open question is not the same as something like dark matter, i.e., something almost inconceivable that has become a standard reference in discussing how the ordinary universe works. We’re still only 100 years away from phrenology — which itself was more interesting than it’s usually given credit for being. Oliver Sacks’ writing is one of the few places in neurology where I see these huge open questions being addressed in the context of real human lives.

  2. #2 Suraj
    March 14, 2007

    “Is this neuroscientific confidence justified? Or is it just the brash braggadocio of a young science? Why do we have more faith in our microscopes than in our telescopes?”

    Well, I dont feel that its the overconfidence of the neuroscientist that makes him self-assertive as Jonah mentioned.. Rather, it stems from the humility imposed on us by the “overwhelming” simplicity of living organism and its powers to generate the grandest illusions. I may sound a bit awkward here, but just follow me thru’ this and it will be clear:
    What has neuroscience, thru its infinite expositions in the past few decades shown us?

    Its nothing but that the whole concepts of “conscious self”, “ego”, and the grand phenomenon called “mind” is just an illusion created by the zillion electrical interactions in the animal body… In that respect, any living organism with a nervous system can theoretically have a “conscious mind”.

    Quantum physics and cosmology seems to be inventing ad-hoc theories and particles almost on a daily basis in an attempt to incorporate as much of the latest discoveries into our classical views of commonsense-based world..but those, I think are in vain…Our commonsense and mathematical ability evolved in an infinitesimally small corner of this universe and can hardly “see” things in 3Dimension – forget four or eleven dimensions of the quantum cosmos…!!
    If strings “vibrate” in different dimensions to produce quarks,photons,electrons, positrons, atoms and molecules then the “mind” can be considered just another manifestation of the “strings” of matter/energy that form the stuff and style of the universe. That’s the point of revelation of a disarming but intriguing truth: WE CAN NEVER HOPE TO COMPREHEND A UNIVERSE FROM WHICH WE EVOLVED..!

    But still, as scientists, we can’t stop packing our bags for this wild goose chase, thats our instinct…that keeps us “high”…thanks to those pleasure centers in our brain stem..heh he.. ;)

    dr.surajrajan@gmail.com

  3. #3 son2
    March 14, 2007

    …the strange discoveries of the 20th century: the multiple dimensions of string theory, the invisibility of dark matter, the stubborn chasm separating Einstein and quantum mechanics.

    Jonah, Jonah, Jonah! How about the 20th century discoveries of relativity, superconductivity (basically just quantum mechanics), lasers (again, just QM), or the families of subatomic particles! …but, string theory?

    Also, you think physicists are more willing to admit their ignorance? Ha! Not the ones I’ve met. But I think it’s a different thing for an average (non-cosmologist) physicist to discuss the current limits of physical knowledge than for a neuroscientist to discuss mysterianism, for political reasons.

    Imagine if cosmologists speculated about the limits of understanding the beginning of the universe? That would cause a huge stir because the creation of the universe is a focal point for a lot of people’s religious and political ideologies. Ditto for consciousness.

  4. #4 From so simple a beginning
    March 14, 2007

    It is a beautiful article, Jonah.

    “neuroscientists are more averse to discussions of mystery and the limits of knowledge… that they are unwilling to let some immaterial presence back in.”

    For whatever it is worth, I think Cosmologists are unwilling to let immaterial presence back in too. After all, just because we can’t see it does not make dark matter an “immaterial presence”. In fact, “immaterial presence” is the most lame way of talking about mystery and limits of knowledge.

    Scientists of all stripes are wary of being mistaken to be talking about some kind of “immaterial presence”, when they are talking about a much more subtle mystery. And, I think, this wariness is responsible for their general reluctance to
    explore this question in the public.

    I personally don’t know many neuroscientists and I should concede that you definitely know better. But, from outside, I find say this article by Steven Pinker is as much filled with “mysterian musings” as the article on dark matter, if not more.

    And if you allow me, may I suggest that your statement on

    “[how according to neuroscientists] our subjective experience is reduced into a few neural networks in the PFC.”

    sounds more like a caricature of what neuroscientists actually say?

  5. #5 Jonah
    March 14, 2007

    Thanks for your comments. And you’re absolutely right to mention that Steven Pinker article. This post was partially inspired by a conversation I had with a neuroscientist friend and a few of his labmates about that article. They just didn’t get what the mystery was. They found the whole mind/body problem was completely uninteresting. As my friend put it, “Mysteries like that are so 18th century.”

  6. #6 Clark
    March 14, 2007

    First time I’ve ever heard physics congratulated for humility rather than berated for having a Jehovhah complex. (LOL)

  7. #7 Simon
    March 14, 2007

    I recently had a chance to talk to Nobel prize winning physicist David Politzer. He claimed, among other things, that there are no large gaps in our understanding of basic physical laws. When we got onto the topic of consciousness, he took the eliminative materialist position: consciousness does not exist, since it is not a physical phenomenon, and all the physical phenomena can be explained through physical laws.

    There is so much confidence in the future of neuroscience because it is a new discipline. Neuroscience has developed from a rudimentary set of neuropsychological observations to a respectable but far from complete body of knowledge in under a century. Until we understand the neuronal substrates of behavior, it seems illogical to conclude that we can never understand the neuronal correlates of consciousness. Neuroscience is where physics was in the 19th century. We are still in search of our Faraday and Maxwell, but it seems too early to say that we will never find them.

  8. #8 DavidD
    March 15, 2007

    There are some fundamental things about physics that are very well known. To land a spacecraft on Mars with incredible accuracy, you don’t even need physics’ best theory of gravity, general relativity. The back-up theory of gravity that Newton worked out is fine.

    Physics can cover almost everything there is around us with the four 20th-century forces, with the four most common particles, the up and down quarks, the electron, and the neutrino, and the four obvious dimensions. Then people can get exotic about what more there is way out there, way back to the ulimate origin of the universe, or a deeper understanding of everything with new vacuum forces. Hardly anyone minds. The wackier something is, the more interesting, like parallel universes. Because the forces that make it safe for me to sit in my chair are so stable, it’s not worrisome to think about something wacky out there.

    Neuroscience is different. It has some basic things. It has had neurons as units ever since Ramon y Cajal. It has neurotransmitters. It has some knowledge about how many things go into how humans go from a stimulus to a response. Then there’s this gaping whole. None of us live in the real world as much as we live in the virtual world in which our individual consciousness resides, even those who say consciousness doesn’t matter. One can only get away with saying that because consciousness is so close to the objective world we all agree on, at least in terms of sensory images.

    How does our brain do that? When I practiced as a neurologist I saw a lot of people who seemed conscious, though not themselves in some ways, but then they had no memories for a number of days when they were like that, and when they were themselves again, they stop propositioning the nurses every 5 minutes, things like that. Were they really unconscious despite looking conscious?

    Then there are those people such as mentioned in Steven Pinker’s article, people with surprisingly conscious-looking activity on an EEG, now on neuroimaging. Are they really conscious though they look unconscious?

    Anyone can answer those questions however they want, because who know what the answer is? We all know consciousness is a subjective experience of the world as I’m having right now, and it depends on my brain being awake and healthy. Then people argue. Most neuroscientists I know stick to a party line, that consciousness is the integration of brain functions that we haven’t quite completely understood yet, but we know we’re close.

    That was my line in my youth. Then just some simple wondering would come to me. Where is this unconscious mind that some believe in? In the 19th century there was plenty of unknown cerebral cortex for Freud to put an unconscious mind. That’s not true now. Can our memory really fit in our brain? One explanation for the holographic quality of memory is that memory isn’t in the brain to be destroyed by injury. That would mean that it’s in something immaterial that no good scientist wants to consider.

    I’ve read various presentations of what consciousness is. I like Susan Blackmore’s short book on that. My summary of that is we don’t know what the scientific basis of consciousness is beyond needing an awake and healthy brain. It amazes me to think about how I wake up each morning with almost the same consciousness I had the day before. How is it so stable? I imagine a trivial answer to that as it being the same brain, so of course, it’s the same consciousness. Why? What is there in neuroscience to tell me why that should be? Is consciousness like my shadow? Is there some simple optical principle that explains it? Then what is it? I think I vary more during the course of a day than I do on awakening each morning. Why is that?

    Mainstream neuroscientists can only say that there is this mystery called consciousness, but it can’t be that important because not understanding it hasn’t hindered their work. As a matter of fact, maybe it doesn’t matter at all. Yes, any day now, machines will become conscious and show that it’s no big deal. OK, I haven’t heard neuroscientists say that last part lately.

    But there is this big hole in neuroscience about consciousness. Maybe everything about the mind can be explained materialistically. Maybe consciousness, unconsciousness and memory all really do squeeze together alongside each other in our cerbral cortex in such an orderly way that we have no choice but to see green as green and wake up as ourselves every morning. Maybe neuroimaging will reveal in this century things that have been hard to discuss neurologically like will and desires. Maybe in a hundred years the hole in neuroscience that is consciousness will fill in as easily as some say.

    I just have this feeling that when Neils Bohr first made his classical model of the electron orbiting a proton he felt as confident as neuroscientists do now about consciousness being merely an emergent property of the brain. I wonder if someone else had to tell Professor Bohr that there was a problem with this model, after which physics got strange. Neuroscience will either be like that, or it won’t.