Don't worry, Church of the Churchless visitors who aren't as interested as I am in the hot new neuroscience theory of predictive processing by the brain, which is why I've been writing about Andy Clark's book The Experience Machine recently.
I'll be on to other topics soon. But not quite yet, since I want to share some of what I learned by watching Shamil Chandaria's talk on YouTube about "The Bayesian Brain and Meditation." I heard Chandaria and Sam Harris engage in a fascinating conversation on Harris' Waking Up app.
That led me to watch Chandaria's talk, since he's knowledgeable about the whole predictive processing thing, and also an avid meditator based on what he said to Harris. So I figured I might learn something about a topic that's been a subject of debate on this blog: whether it is possible for the human brain to function without filters or models.
I and a frequent commenter said no, it isn't. Another frequent commenter said yes, it is. So this is why I bring up that subject in my observations about some slides from Chandaria's presentation that I'm sharing below in the form of screenshots.
The theory of predictive processing by the brain fascinates me because it explains some things about the brain in a clearer fashion. For example, Harris (who has a Ph.D. in neuroscience) noted in his talk with Chandaria that there are ten times more top down connections between the brain and senses than bottom up connections.
Meaning, the brain is giving a lot more information to the senses than the senses are giving to the brain. This is at odds with the traditional way of looking at this: the senses communicate what's in the world to the brain; the brain then cognizes about that information; then the motor part of the brain decides on actions in accord with what the senses are saying.
Actually, the reverse is true, according to prediction processing theory. The brain, which has no direct connection to the world, is continually making predictions about what is out there based on prior experience and sense data. Errors caused by a mismatch between a prediction and sense data are what the brain pays most attention to, not sense data that matches a prediction.
The first part of Chandaria's talk was a bit drier and more technical than the part about meditation, because that initial part centered on what a Bayesian way of looking at things consists of. Key concepts include priors, or expectations, which basically is a prediction before new data is available. Sensory data then combine with the priors to produce a judgment about what is happening in the world.
(I've probably garbled what Bayesian statistics is all about, since I'm no expert on it. Watch the first part of the video for an expert explanation.)
These are the families of meditations discussed by Chandaria: the Attentional Family, the Deconstruction Family, and the Constructive Family.
Focused attention meditation is what most people think of when the subject of meditation arises. The dim objects in the thought bubble on the left represent the variety of things in the world that attention could alight on.
If a meditator focuses attention on a single object, such as the breath (the nose image), then other objects receive less attention. Or in the jargon of predictive processing, a decreased precision weighting -- which probably should just be called "weighting."
Deconstruction meditation such as some forms of mindfulness, analytical meditation, and koan practice is different in that the goal is to descend in the hierarchy used by the brain to model the world. For example, on the far left of the slide is a row where the top level is entire faces, the middle level is parts of faces, and the bottom level is parts of those parts.
The brain constructs a face by taking raw vision data and processing it upward from lines, curves, and such, to eyes, lips, nose, and such, ending up with the highest level of a complete face. Deconstruction moves in the opposite direction. Chandaria used the example of saying "dog" twenty times in a row rapidly until the word becomes a mere sound, not a symbol for a canine. (The slide does this with "flowers.")
Now, while it might seem that deconstruction is in line with the idea that the brain can function without filters or models, note in the slide above that Chandaria calls raw body sensations and raw sounds "low level models." So even raw sensory data is still minimally processed by models in the brain.
And of course it is difficult to imagine being able to function as a human with only raw sensory data. Even newborn infants quickly move away from the "blooming and buzzing confusion" William James termed their initial experience of the world as pure sensation. Who would want to live as a newborn for their entire life?
Probably the closest Chandaria came to talking about something that believers in the brain being able to function without filters or concepts would applaud is when he spoke of awareness as being the substrate on which the generative prediction processing model arises. Of course, it seems obvious that awareness or consciousness is the foundation of all experience, without exception.
This gets us into some murky philosophical and neuroscientific waters, since it is unclear what non-dual awareness actually consists of, or what awareness consists of. Is it possible for there to be awareness without any object of awareness? Some people believe in this. Me, I don't, but I could be wrong about this.
At any rate, non-dual awareness is much more of a spiritual or mystical notion, than a neuroscientific one.
Emptiness, in the Buddhist sense, is one of the spiritual notions (in the blue box) that Chandaria says are similar phenomenology (meaning, as experienced) yet with different metaphysical narratives. That's for sure. Brahman, God in Hinduism, is very different from Buddhist emptiness -- which means the interdependence of all things, none of which possess inherent existence in their own right.
The orange'ish note in the middle says: "NB Awareness itself is empty. It's not a thing. Tendency to reify it." [I"m confident this is a typo, since he is talking about ND, nondual, awareness.) So whatever non-dual awareness is, it isn't a thing. Chandaria also said "Everything is a construction," which supports my contention that the brain doesn't function without filters and models.
The thought cloud with a bunch of objects in it shows that non-dual awareness, as Zen teaches, is simply the union of subject and object where awareness isn't divided into (1) an experience of something by (2) an experiencer of that thing. There's just experience.
Chandaria presented an interesting three-dimensional model of meditation. (Not mediation.) Thr three dimensions are attention, non-dual awareness, and deconstruction. Note that under deconstruction he speaks of brain functioning becoming opaque rather than transparent. Meaning, the goal is to understand how the brain constructs reality instead of having this be automatic.
The peak meditation that combines all three dimensions to the greatest extent is in the upper top right corner: "Deep non-dual absorption state. Minimal Phenomenal Awareness (MPE). [Or MPA; Chandaria could use a proofreader for his slides.]
Chandaria said there are only a few people working on predictive processing models of meditation. He included references to two papers, one of which he was an author on. He didn't explain this slide in any detail. Guess you have to read the references.
Meditation, along with psychedelics, is a way of reconstructing ourself after deconstructing ourself. The discussion in blue also supports my contention that the brain always is going to use filters and models. But it's possible to use our knowledge of the brain to reshuffle our assumptions, expectations, predictions, and such about the world.
Chandaria calls this entering into a reprogramming mode. There's still a program running in the brain. The outputs are just more to our liking, hopefully.
This was one of his last slides. Again, Chandaria says that our experience of the world is a construction, which strongly implies filters and models always will be with us, since those are the brain's construction tools.
But we have the ability to make our experience as beautiful as possible.
For those following the comment game, Spence Tepper lost
For those who have been following the interesting exchange of views about consciousness and the brain in comments on a recent blog post, I'm pleased to present the final score on a debate about whether there's evidence that awareness can be free of filters and concepts.
Commenter Spence Tepper ended up without scoring a debate point due to his religious dogmatism. Commenters Appreciative Reader and myself scored numerous debate points because we used facts and logic. Tepper never actually played the debate game, choosing to ignore calls to produce evidence for his assertion.
Bottom line: you can't win a game unless you're willing to play the game. Calling out "I won!" from the sidelines is a spectator sport, not a genuine sport.
Here's how Appreciative Reader put it in his typically courteous and reasonable fashion.
Most of what you say now, in this last comment, is reasonable, and I agree generally with most of that, I guess.
Except! Except, that isn't what this was about, was it. You'd claimed, originally, that meditation enables us to bypass the model-building thing of our brain, and bypass those mental filters to apprehend reality directly. That extravagant claim of yours is what Brian had flagged, and asked you to substantiate. And pre-empting exactly this kind of bobbing and weaving, I'd wondered if you could do that, without changing the subject etc.
(Here's your own words, that Brian had quoted there: "...if we can go to that place of awareness within ourselves free of filters, a place where filtering and conceptual reconstruction do not function, who knows what we may experience? Maybe God? But no label would work there. Maybe reality directly. Maybe pure experience of the moment. Maybe the moment is eternity." And you've said similar, often enough, other times as well.)
If you'd been able to substantiate that claim, then that would have been fantastic. I'd have been first to accept it, and change my mind and my worldview accordingly. If you hadn't been able to do that, even then, had you directly admitted that that isn't evidenced, but merely how it appears to you, personally and subjectively, and what some religious traditions teach, fair enough, no harm done. We'd then have known clearly where we stand. And nor would that have detracted from your experiences --- except we wouldn't be then looking at them as (allegedly) a "direct" apprehension of reality.
As it happens, you did neither. In your reply to Brian, you simply doubled down, with this further extravagant and unevidenced claim thrown in: "You have experience but it is often entirely beyond the thinking brain, and so without impression, zero memory. You think you saw nothing. But thinking is the problem. You saw something, you can't think of it. (...) You'll have to Grok it. Sartori it."
Once again, the claim that in meditation you experience something that is beyond the thinking brain. In as much as these words of yours are linked to what you'd said before, presumably you mean to imply that this is that direct apprehension of reality, that you'd referred to earlier.
In other words, all you did was to "substantiate" your extravagant claim, with yet another extravagant and unevidenced claim.
And now, now you present to me very reasonable comments, very wise views on meditation, and indeed evidenced opinions on meditation. All of which I agree with. Except none of them have anything to do with that original claim.
The one part of your comment now that does directly deal with that original claim is where you say: “Part of that reality reconstruction the brain does all the time. We don't have to be a willing, mindless participant in that.”
That’s worded kind of ambiguously, but it seems to indicate that meditation allows you to go outside of the reconstruction, the model building, that the brain does. In which case it’s simply you repeating your original claim, yet again, in different words, instead of substantiating it. (And yes, like I said that's worded ambiguously. If you didn't mean to convey that by those words, then fair enough, I take this last back. But in that case, again, this has nothing to do with your original claim at all.)
As for the Mayo Clinic link, it’s a cool article, and I enjoyed reading it. But it’s simply a general article written by the clinic staff, a kind of overview of meditation, and it doesn’t come close to providing the kind of evidence we’re talking about here; and nor does it actually claim, either, that meditation helps you apprehend reality directly and minus the filters of mental model-building.
It's a straightforward issue. You know my views on meditation. I'm a fan, and in fact a practitioner and aspirant myself. I agree that meditation is generally beneficient, in terms of what you've discussed here, and more. In general I'm interested in knowing more about all of that, sure.
But the issue we're focused on at this time is this: Can meditation enable us to bypass the model-building via which filter we apprehend reality indirectly, so that we might be able to apprehend reality directly? That had been your claim. Can you substantiate it? If not, then I don't see the issue with clearly admitting it, and retracting that original claim. (And nor do you need jettison that POV altogether. You can always present it, instead, and if you like, as a speculation, maybe, rather than as fact. We can speculate all we want, about whatever we want, why not, as long as we're clear that speculating is all we're doing.)
Not to force the issue beyond this! And apologies if any of my comments in this thread appeared less than fully courteous. Absolutely no offense intended, Spence. Cheers.
Posted at 10:52 AM in Comments, Neuroscience | Permalink | Comments (30)