All of Jeff Beck's Comments + Replies

The short answer is that, in a POMDP setting, FEP agents and RL agents can be mapped one onto the other via appropriate choice of reward function and inference algorithm.  One of the goals of the FEP is to come with a normative definition of the reward function (google the misleadingly titled "optimal control without cost functions" paper or, for a non-FEP version of the same, thing google the accurately titled: "Revisiting Maximum Entropy Inverse Reinforcement Learning").  Despite the very different approaches, the underlying mathematics is very... (read more)

2Steven Byrnes
Thanks again! Feel free to stop responding if you’re busy. Here’s where I’m at so far. Let’s forget about human brains and just talk about how we should design an AGI. One thing we can do is design an AGI whose source code straightforwardly resembles model-based reinforcement learning. So the code has data structures for a critic / value-function, and a reward function, and TD learning, and a world-model, and so on. * This has the advantage that (I claim) it can actually work. (Not today, but after further algorithmic progress.) After all, I am confident that human brains have all those things (critic ≈ striatum, TD learning ≈ dopamine, etc.) and the human brain can do lots of impressive things, like go to the moon invent and quantum mechanics and so on. * But it also has a disadvantage that it’s unclear how to make the AGI motivated to act in a human-like way and follow human norms. It’s not impossible, evidently—after all, I am a human and I am at least somewhat motivated to follow human norms, and when someone I greatly admire starts doing X or wanting X, then I also am more inclined to start doing X and wanting X. But it’s unclear how this works in terms of my brain’s reward functions / loss functions / neural architecture / whatever—or at least, it’s presently unclear to me. (It is one of my major areas of research interest, and I think I’m making gradual progress, but as of now I don’t have any good & complete answer.) A different thing we can do is design an AGI whose source code straightforwardly resembles active inference / FEP. So the code has, umm, I’m not sure, something about generative models and probability distributions? But it definitely does NOT have a reward function or critic / value-function etc. * This has the advantage that (according to you, IIUC) there’s a straightforward way to make the AGI act in a human-like way and follow human norms. * And it has the disadvantage that I’m somewhat skeptical that it will ever be possible to actu

I will certainly agree that a big problem for the FEP is related to its presentation.  They start with the equations of mathematical physics and show how to get from there to information theory, inference, beliefs, etc.  This is because they are trying to get from matter to mind.  But they could have gone the other way since all the equations of mathematical physics have an information theoretic derivation that includes a notion of free energy.  This means that all the stuff about Langevin dynamics of sparsely connected systems (the 'pa... (read more)

2Steven Byrnes
I’m generally in favor of figuring out how to make AIs that are inclined to follow human norms / take human-typical actions / share human-typical preferences and can still do human-level R&D etc. That seems hard basically for reasons here (section “recognizing human actions in data”) and the fact that most actions are invisible (e.g. brainstorming), and the fact that innovation inevitably entails going out of distribution. But first I have a more basic question where I’m confused about your perspective: * Do you think it’s possible for the exact same source code to be either a “FEP agent” or an “RL agent” depending on how you want to think about things? * Or do you think “FEP agent” and “RL agent” are two different families of algorithms? (Possibly overlapping?) * And if it’s this, do you think both families of algorithms include algorithms that can do human-level scientific R&D, invent tools, design & build factories, etc.? Or if you think just one of the two families of algorithms can do those things, which one? * And which family of algorithms (or both) would you put the human brain into? Thanks!

There is a great deal of confusion regarding the whole point of the FEP research program.  Is it a tautology, does it apply to flames, etc.  This is unfortunate because the goal of the research program is actually quite interesting:  to come up with a good definition of an agent (or any other thing for that matter).  That is why FEP proponents embrace the tautology criticism:  they are proposing a mathematical definition of 'things' (using markov blankets and langevin dynamics) in order to construct precise mathematical notions of ... (read more)

3Steven Byrnes
Thanks for the comment! Your comment is a bit funny to me because I think of algorithms and definitions as kinda different topics. In particular, I think of RL as a family of algorithms, not as a definition of an agent. If I have I have a robot running an RL algorithm, and I have a sufficiently thorough understanding of how the algorithm works and how the robot works, then I can answer any question about what the robot will do, but I haven’t necessarily made any progress at all on the question of “what are its beliefs?” or “is it an agent?” For example, we can easily come up with edge cases where the question “what do I (Steve) believe?” has an unclear answer, even knowing everything about how I behave and how my brain works. (E.g. if I explicitly deny X but act in other ways as if I believe X, then is X part of my “beliefs”? Or if I give different answers about X depending on context and framing? Etc.) Conversely, I presume that if we had a rigorous mathematical definition of “beliefs” and “agents” and whatever, it would not immediately tell us the answers to algorithms questions like how to build artificial general intelligence or how the brain works. In terms of definitions: If FEP people someday use FEP to construct a definition of “agent” that reproduces common sense, e.g. I'm an agent, a rock isn't an agent, a flame isn't an agent, etc., then I’d be interested to see it. And if I thought that this definition had any kernel of truth, the first thing I’d try to do is reformulate that definition in a way that doesn't explicitly mention FEP. If I found that this was impossible or pointlessly convoluted, then I would count that as the first good reason to talk about FEP. I am currently skeptical that any part of that is going to actually happen. As it happens, I have some friends in AGI safety & alignment interested in the question of how to define agency, goals, etc. (e.g. 1,2). I guess I find such work slightly helpful sometimes. I’ve gone back to this post