You can see that perception and action rely on the same mechanism in many ways, starting with the simple fact that when you look at something you don’t receive a static picture, but rather constantly saccade and shift your eyes, contract and expand your pupil and cornea, move your head around, and also automatically compensate for all of this motion.
How does this suggest that perception and action rely on the same mechanism, as opposed to are very intertwined? I would certainly agree that motor control in vision has tight feedback loops with vision itself. What I don’t believe is that we should model this as acting so as to minimize prediction loss. For one thing, I’ve read that a pretty good model of saccade movement patterns is that we look at the most surprising parts of the image, which would be better-modeled by moving eyes so as to maximize predictive loss.
Babies look longer at objects which they find surprising, as opposed to those which they recognize.
It’s true that PP can predict some behaviors like this, because you’d do this in order to learn, so that you minimize future prediction error. But that doesn’t mean PP is helping us predict those eye movements.
In a world dependent on money, a money-minimizing person might still have to obtain and use money in order to survive and get to a point where they can successfully do without money. That doesn’t mean we can look at money-seeking behavior and conclude that a person is a money-minimizer. More likely that they’re a money-maximizer. But they could be any number of things, because in this world, you have to deal with money in a broad variety of circumstances.
Let me briefly sketch an anti-PP theory. According to what you’ve said so far, I understand you as saying that we act in a way which minimizes prediction error, but according to a warped prior which doesn’t just try to model reality statistically accurately, but rather, increases the probability of things like food, sex, etc in accordance with their importance (to evolutionary fitness). This causes us to seek those things.
My anti-PP theory is this: we act in a way which maximizes prediction error, but according to a warped prior which doesn’t just model reality statistically accurately, but rather, decreases the probability of things like food, sex, etc in accordance with their importance. This causes us to seek those things.
I don’t particularly believe anti-PP, but I find it to be more plausible than PP. It fits human behavior better. It fits eye saccades better. (The eye hits surprising parts of the image, plus sexually significant parts of the image. It stands to reason that sexually significant images are artificially “surprising” to our visual system, making them more interesting.) It fits curiosity and play behavior better.
By the way, I’m actually much more amenable to the version of PP in Kaj Sotala’s post on craving, where warping epistemics by forcing belief in success is just one motivation among several in the brain. I do think something similar to that seems to happen, although my explanation for it is much different (see my earlier comment). I just don’t buy that this is the basic action mechanism of the brain, governing all our behavior, since it seems like a large swath of our behavior is basically the opposite of what you’d expect under this hypothesis. Yes, these predictions can always be fixed by sufficiently modifying the prior, forcing the “pursuing minimal prediction error” hypothesis to line up with the data we see. However, because humans are curious creatures who look at surprising things, engage in experimental play, and like to explore, you’re going to have to take a sensible probability distribution and just about reverse the probabilities to explain those observations. At that point, you might as well switch to anti-PP theory.
How does this suggest that perception and action rely on the same mechanism, as opposed to are very intertwined? I would certainly agree that motor control in vision has tight feedback loops with vision itself. What I don’t believe is that we should model this as acting so as to minimize prediction loss. For one thing, I’ve read that a pretty good model of saccade movement patterns is that we look at the most surprising parts of the image, which would be better-modeled by moving eyes so as to maximize predictive loss.
Babies look longer at objects which they find surprising, as opposed to those which they recognize.
It’s true that PP can predict some behaviors like this, because you’d do this in order to learn, so that you minimize future prediction error. But that doesn’t mean PP is helping us predict those eye movements.
In a world dependent on money, a money-minimizing person might still have to obtain and use money in order to survive and get to a point where they can successfully do without money. That doesn’t mean we can look at money-seeking behavior and conclude that a person is a money-minimizer. More likely that they’re a money-maximizer. But they could be any number of things, because in this world, you have to deal with money in a broad variety of circumstances.
Let me briefly sketch an anti-PP theory. According to what you’ve said so far, I understand you as saying that we act in a way which minimizes prediction error, but according to a warped prior which doesn’t just try to model reality statistically accurately, but rather, increases the probability of things like food, sex, etc in accordance with their importance (to evolutionary fitness). This causes us to seek those things.
My anti-PP theory is this: we act in a way which maximizes prediction error, but according to a warped prior which doesn’t just model reality statistically accurately, but rather, decreases the probability of things like food, sex, etc in accordance with their importance. This causes us to seek those things.
I don’t particularly believe anti-PP, but I find it to be more plausible than PP. It fits human behavior better. It fits eye saccades better. (The eye hits surprising parts of the image, plus sexually significant parts of the image. It stands to reason that sexually significant images are artificially “surprising” to our visual system, making them more interesting.) It fits curiosity and play behavior better.
By the way, I’m actually much more amenable to the version of PP in Kaj Sotala’s post on craving, where warping epistemics by forcing belief in success is just one motivation among several in the brain. I do think something similar to that seems to happen, although my explanation for it is much different (see my earlier comment). I just don’t buy that this is the basic action mechanism of the brain, governing all our behavior, since it seems like a large swath of our behavior is basically the opposite of what you’d expect under this hypothesis. Yes, these predictions can always be fixed by sufficiently modifying the prior, forcing the “pursuing minimal prediction error” hypothesis to line up with the data we see. However, because humans are curious creatures who look at surprising things, engage in experimental play, and like to explore, you’re going to have to take a sensible probability distribution and just about reverse the probabilities to explain those observations. At that point, you might as well switch to anti-PP theory.