I'm continuing to read and enjoy Andy Clark's The Experience Machine: How Our Minds Predict and Shape Reality. It's one of the best books about modern neuroscience that I've ever read, and believe me, I've read a lot of them.
My first post about the book laid a foundation for these subsequent posts, as I get deeper into The Experience Machine. This is a one sentence summary of the Big Idea discussed in the book -- which makes a heck of a lot of sense.
Predictions and prediction errors are increasingly recognized as the core currency of the human brain, and it is in their shifting balances that all human experience takes shape.
In a "Psychiatry and Neurology" chapter, Clark talks about prediction errors. Those are the difference between what the brain expects to perceive, given sensory inputs and prior experience, versus what is actually perceived.
Ideally those errors are reduced as we learn more about the slice of reality we're attending to.
But sometimes they aren't, which can create problems for us, big or small. Here's how Clark explains this. It won't be completely understandable, since I'm just sharing small excerpts from his book, but you should get the gist of his message.
Varying estimates of precision alter patterns of post-synaptic influence and so determine what (right here, right now) to rely on and what to ignore. This is also the way brains balance the influence of sensory evidence against predictions.
In other words, precision variations control which bits of what we know and what we sense will be most influential, moment by moment, in bringing about further processing and actions. Expressed like that, the intimacy of precision and attention is apparent.
Precision variation is what attention (a useful but somewhat nebulous concept) really is.
For example, suppose I want to find a needle recently dropped in a bed of hay. According to predictive processing, my brain ups the precision-weighting on specific aspects of the visual information that would indicate a small silvery object, thereby increasing my chances of success.
That's what attention, if these accounts are correct, really is -- attention is the brain adjusting its precision-weightings as we go about our daily tasks, using knowledge and sensing to their best effect. By attending correctly, I become better able to spot and respond to whatever matters most for the task I am trying to perform.
Precision estimation is thus the heart and soul of flexible, fluid intelligence.
But what happens when precision estimations misfire? This would skew the impact of different bits of sensory evidence, and of different predictions. Precision estimation is the brain's way of telling itself where, and by how much, to place its bets.
When this goes wrong, our brains will bet badly; they will misestimate what to take seriously and what not to take seriously, thereby generating false or misleading experiences. This is exactly what seems to be happening with functional disorders. In these cases, unwilled misallocations of precision act as self-fulfilling prophecies.
Predictions of pain or impairment become highly overweighted, and those predictions overwhelm the actual sensory evidence, forcing experience to conform to our own hidden but misplaced expectations.
I found examples of this to be fascinating.
As I said in my first post about the book, it's going too far to say that this proves that we create our own reality. However, our brains definitely shape our experience of reality, sometimes in disturbing ways. "Functional" here means that there is a loss of function without evidence of systemic, or structural, damage of disease.
There is good evidence that misfiring precision assignments (unusual patterns of attention) play a role in many, perhaps all, functional neurological disorders. For example, simply distracting the sufferer by making them direct their attention elsewhere often makes functional (but not structural) tremors vanish.
...This creates a version of the famous "refrigerator light illusion." You might infer that your fridge light is constantly on just because the light is on every time you look inside. But actually it is the act of looking (opening the door) that turns on the light.
Similarly, you might believe you have a near-constant tremor because the tremor is always there when you pay attention to it. But if the tremor is actually in whole or in part the result of the process of "predicting and attending" itself, that assumption may be wildly wrong.
...Strongly anticipating pain, numbness, weakness, or other symptoms alters patterns of attention (precision-weightings) in ways that can either amplify or entirely generate the experience -- which then seems to confirm those very expectations.
...To make sense of these self-constructed feelings of pain, numbness, weakness, or paralysis, sufferers may start to suspect deep hidden causes -- such as persistent hidden illness. These new beliefs then further reinforce the expectations of those symptoms, reinforcing the cycles of aberrant attention.
...This is rather like the case of the performer with stage fright whose true abilities are masked by their own mounting expectations of failure. The circularity is daunting. Every new instance of stage fright confirms the expectations of failure, and those expectations ensure that the instances of failure accumulate.
Recognizing this circularity is, however, often the first step in breaking the cycle, as we'll see later when looking at ways to "hack" our own predictive brains.
For lots of people, pain is an unpleasant part of their daily life. Clark speaks about pain in this chapter.
Individuals will differ in how they assign precision to bodily signals, including those associated with pain and disability. Moreover, living with a condition for a long time enables idiosyncratic expectations (for example, about severity in different contexts) to arise and become ingrained.
This means that even where there is some standard structural cause such as a bulging or herniated disc in someone with back pain, the way we experience our symptoms may over time come to involve large doses of mindset and expectation.
In a certain sense, chronic pain at that point is perhaps best considered not so much as a symptom, but as the disease itself -- the very state that needed to be addressed.
...It shows us exactly why, as leading pain theorist Mick Thacker puts it, we need to move away from thinking of pain as a simple sensation, a direct signal of damage or potential damage, to a view of pain as a perception.
Like all perceptions, it takes shape only thanks to the precision-weighted interaction of predictions and current bodily signals. It is that process of combination that provides the wiggle room that enables persistent pain or impairment without damage, threat, or disease.
This is not to say that everything will respond to changes in expectations. It won't. But attention and expectation are key players in the construction of all our experiences of health and illness, and this is true even when standard structural causes (damage or disease) are present.
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 (9)