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The Rewiring of the Living Software 9:05 Lena: We’ve talked about how the brain builds these models, but I’m curious about how they change. If the brain is a "prediction machine," it can’t just be stuck with the same guesses forever, right? I mean, I’m not the same person I was ten years ago. I’ve learned new skills, changed my habits. How does the "software" update?
9:25 Miles: That’s where the concept of the brain as "living software" comes in. Unlike a computer, where the hardware is fixed and the software runs on top of it, the brain’s hardware *is* the software. David Eagleman uses the term "livewired" to describe this. Every time your brain encounters a "prediction error"—when the world doesn't match its guess—it has an opportunity to rewire.
9:48 Lena: So, a mistake is actually a moment of growth?
9:51 Miles: Literally! From a neurological perspective, a prediction error is the only time the brain is actually forced to do hard work. If your predictions are perfect, your brain can stay on autopilot. But when you encounter something unexpected—like trying to learn a new language or navigating a city you’ve never been to—the "bottom-up" sensory signals are screaming, "The model is wrong! Update required!" This triggers neuroplasticity. The connections between neurons physically shift to accommodate the new data.
10:21 Lena: It makes me think about how kids learn. They’re basically prediction-error machines. They’re constantly bumping into things, tasting things they shouldn't, and asking "why" a million times. Their internal models are being updated at a staggering rate.
10:36 Miles: Absolutely. And as we get older, we tend to get better at predicting our environment, which is why time seems to speed up. When you’re a child, everything is a surprise—the world is full of high-intensity prediction errors, so your brain is recording everything in high detail. As an adult, you’ve seen it all before. You walk down the same street, eat the same breakfast, do the same job. Your predictions are mostly "correct," so your brain doesn't bother recording much of the data. The "dark room" just plays the same old tape.
11:06 Lena: That’s a bit depressing, Miles! Are we doomed to just live in a stale simulation as we age?
11:13 Miles: Not at all! The beauty of "living software" is that we can intentionally introduce novelty. By putting ourselves in new situations, we force the brain to update its models. This is why travel, learning a new instrument, or even just taking a different route to work can feel so refreshing. You’re feeding the prediction machine new types of error, which keeps the system flexible.
11:33 Lena: It’s like Jeff Hawkins says about the "thousand brains" theory—we have these different columns in the neocortex all learning different aspects of an object. If we only ever look at the "cup" from one angle, our model is thin. But if we turn it, use it for different things, and experiment with it, our model becomes robust.
11:52 Miles: And that robustness is what allows for creativity. Creativity is often just the brain taking two different predictive models and smashing them together to see what happens. It’s using the "hallucination" part of the process to imagine things that *could* be, rather than just what *is*.
12:08 Lena: So, the brain isn't just predicting the present; it’s simulating future possibilities. It’s a "what-if" engine.
12:15 Miles: Right. Daniel Wegner’s work on the "illusion of conscious will" suggests that our sense of "deciding" to do something might actually be a prediction our brain makes *after* it has already started the process. The brain simulates the action, and then the conscious "me" interprets that simulation as an intentional choice. It sounds counterintuitive, but it shows how deep the predictive nature of the mind goes. Even our sense of agency—the feeling that "I" am in control—might be a predictive model designed to help us understand our own behavior.
12:46 Lena: That’s a heavy thought. If my "self" is a model, then who is the one looking at the model?
12:53 Miles: Now you’re getting into the deep waters of consciousness! But from a purely functional level, the "self" is just another map the brain uses to navigate the world. It’s a map of your history, your preferences, and your likely future actions. And just like any other map, it can be redrawn.