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Why Robot Brains Need Symbols

nautil.us

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Re: Why Robot Brains Need Symbols

#31

Post by cs702 »

Actually, deep learning models do use symbols.

We call these symbols "embeddings" or "representations" in a vector or tensor space... but these symbols may not have any known or readily interpretable human meaning. People who are uneducated in basic vector (and tensor) math may have difficulty understanding how this is possible, but it's a fact.

For example, the ELMo embedding of a particular word in a sentence is a symbol that represents the complex syntax, semantics, and polysemy of that word given its location and use in the text.[a] Similarly, a trained WaveNet model represents a sequence of text as a (fairly large) tensor embedding that encodes the information necessary for generating the corresponding speech; this embedding is a symbol too.[b] As a final example, the next-to-last layer's embedding of an image processed through a trained Detectron model contains representations of every identified object in the image; those representations are symbols too.[c]

Moreover, the kind of automatic differentiation that is necessary for training deep learning models with backprop reduces into manipulation of symbols in a tree, viewed through the right lens. Witness, for example, the recent work done by Mike Innes et al for the Julia language.[d] We could very well be in the early stages of adoption of "deep differentiable programming" for a growing number of cognitive tasks that might not be solvable via human manipulation of symbols.

The challenge for deep learning going forward, as Bengio says and Marcus quotes, is in figuring out how to "extend it to do things like reasoning, learning, causality, and exploring the world."[e] As far as I can tell, everyone in the field already agrees on these goals; many researchers are thinking about and wondering how it might be possible to pursue them.

Does Marcus understand this? His complaining about the "lack of symbols" is... misguided, I think.

[a] https://allennlp.org/elmo

[b] https://deepmind.com/blog/wavenet-generative-model-raw-audio...

[c] https://research.fb.com/downloads/detectron/

[d] https://julialang.org/blog/2018/12/ml-language-compiler

[e] https://twitter.com/GaryMarcus/status/1065280340669816832

Re: Why Robot Brains Need Symbols

#32

Post by YeGoblynQueenne »

laichzeit0 wrote: post #29
YeGoblynQueenne wrote: post #24

Earlier quoted context omitted.

>> He ends the essay with "All I am saying is to give Ps (and Qs) a chance.". But who exactly is this aimed at? It's a slightly garbled (and so not immediately recognisable, perhaps) pun on the verse "All that we're saying/ is give peace a chance" from John Lennon's "Give Peace a Chance". So it's not addressed to anyone- it's just his attempt at injecting a bit of levity in the debate. EDIT: >> If Ps (and Qs) is a be…

This comes across a bit like the Tanenbaum–Torvalds monolithic/microkernel debate in the 90s. Tanenbaum in this case is Marcus and Torvalds is LeCunn. There are so many well established benchmarks out there. Just build whatever this symbolic system is that you're advocating and beat the benchmarks. Or maybe create your own benchmarks and then we can also apply Deep Learning to those problems too and see who wins? Unt…

That's what the work I mentioned above does- it beats benchmarks and shows impressive results. The work by Evans and Grefenstette in particular is all out of chewing gum [1].

Somewhat depressingly, your comment makes me guess that you really think that none of that work has actually been done, that it's somehow all theoretical or speculative, or just a lot of twitter talk by Gary Marcus. That couldn't be farther from the truth.

It's really the case that many people have no idea about AI beyond a quick article in the popular press here and there, and despite this, they have already formed very strong opinions about it.

_________________

[1] Here:

https://deepmind.com/blog/learning-explanatory-rules-noisy-d...

Note that the above overview of their paper is published on DeepMind's website (the two are DeepMind employees). You can rest assured that DeepMind in particular, would never support the publication of a paper that doesn't demonstrate impressive results.

Re: Why Robot Brains Need Symbols

#33

Post by scotty79 »

Asooka wrote: post #8
scotty79 wrote: post #5

Earlier quoted context omitted.

I think they need symbols but they just need to be taught symbols. If you kept child stationary and show it just static photos one at a time you wouldn't be surprised that it can't tell bus lying on the side in the snow from a snow plow. What neural networks need is the same thing little children need, motion, rotation, things stacking hitting and occluding each other ... and possibly even interaction. We haven't tau…

On the other hand humans have built-in special processing stages already. One that comes to mind is that the neurons in your eyes in effect run a sharpening filter on the incoming light before the data ever enters your brain. I don't think it's a stretch to propose that we should implement certain features as special-purpose processing stages that the neural network can use, with the goal of having a more efficient s…

> On the other hand humans have built-in special processing stages already.

Yes. But there were cases where human could perform function elsewhere that was usually done in special site when thst site got damaged.

Re: Why Robot Brains Need Symbols

#34

Post by vanderZwan »

FakeComments wrote: post #22
vanderZwan wrote: post #10

Earlier quoted context omitted.

> And right now, the tangible evidence for symbolism is simply not cutting it. In AI/ML perhaps. In the biological and psychological sciences the importance of symbols to cognitive functioning is pretty well established. Just look at how important the mastery of language is for complicated thought. One of the main differences between linguistic thought and other forms of thinking is all about symbol manipulation. (Th…

It’s also pretty well known in math and CS/SE communities. Heck, the mathematical research into the power of language, and in particular the ability to embed models of reasoning into equations to allow you to formalize your meta-reasoning, is what led to the birth of electric computers. So I find it shallow skepticism to suggest there’s not evidence that it would be useful to AI, because literally the most cursory gl…

> The real challenge is and always has been how to combine or embed symbolic reasoning capabilities efficiently within a fuzzier approximator, allowing for “getting close” in a fuzzy way then fine tuning it using more advanced rules.

Well, maybe the problem is that we spent so much time basing models on the visual part of the brain that we overlooked the rest:

https://www.quantamagazine.org/new-ai-strategy-mimics-how-br...

Re: Why Robot Brains Need Symbols

#35

Post by [deleted] »

red75prime wrote: post #28
FakeComments wrote: post #19

Earlier quoted context omitted.

I don’t think we’re able to show our workings for higher level things like proofs. For instance, I can’t tell you (accurately) how I composed the proof conceptually, ie what strategy it takes, or even determined the appropriate steps, ie how I determined to use a particular tactic. I can tell you the premises lead to the conclusion via a chain of reasoning, but that’s the artifact of my thought process, not anything…

> they actually can freely introspect their thought process as part of their thought process. Do you mean that they can in principle? I don't know existing systems, which can inspect their own weights and output a vector of confidence scores that they can recognize classes A, B, C, ...

[deleted]

Re: Why Robot Brains Need Symbols

#36

Post by [deleted] »

Eridrus wrote: post #20
laichzeit0 wrote: post #12

I really don't get Gary Marcus' fundamental problem. He ends the essay with "All I am saying is to give Ps (and Qs) a chance.". But who exactly is this aimed at? Surely no one is being held academically ransom to Deep Learning. If Ps (and Qs) is a better approach then do the research and publish the results. Instead he just seems to whine about it on Twitter all day and attack people who are actually "doing the resea…

Gary isn't a technologist, but he wants to set the stage with critique so that when/if a fusion of the ideas does better he can claim to have been important to that, regardless of the fact that the idea is obvious, and the implementation is what is hard

[deleted]

Re: Why Robot Brains Need Symbols

#38

Post by empath75 »

laichzeit0 wrote: post #12

I really don't get Gary Marcus' fundamental problem. He ends the essay with "All I am saying is to give Ps (and Qs) a chance.". But who exactly is this aimed at? Surely no one is being held academically ransom to Deep Learning. If Ps (and Qs) is a better approach then do the research and publish the results. Instead he just seems to whine about it on Twitter all day and attack people who are actually "doing the resea…

Isn’t the kind of programming that most of us do every single day just symbol manipulation of the kind he describes?

On this site, I click reply, the web server interprets my intention and presents me with a text box, etc.

There’s a level of intelligence in pretty much any computer program. I think we take it for granted now because it’s so engrained in our data to day lives, but it’s remarkable isn’t it?

Just look at how many decisions take place entirely within the ‘minds’ of computers when you try and buy a product on amazon and have it shipped to you.

Everything from the pricing of the goods, to approving your credit worthiness to the logistics of getting it to your house is decided on by computers.

All of that would have to have been done by human beings not very long ago.

If anything, symbol manipulation has become such a dominant paradigm for artificial intelligence that we don’t actually recognize any of those activities as requiring intelligence any more — which is always the case every time we mechanize thought.

The question is really whether either of those paradigms gets us to a “general” ai (whatever that is), or both, or neither.

Re: Why Robot Brains Need Symbols

#39

Post by drb91 »

laichzeit0 wrote: post #12

I really don't get Gary Marcus' fundamental problem. He ends the essay with "All I am saying is to give Ps (and Qs) a chance.". But who exactly is this aimed at? Surely no one is being held academically ransom to Deep Learning. If Ps (and Qs) is a better approach then do the research and publish the results. Instead he just seems to whine about it on Twitter all day and attack people who are actually "doing the resea…

This is an article in a popular magazine, and there is no “problem” nor any “whining”. Except here in the comments, oddly!

Re: Why Robot Brains Need Symbols

#40

Post by empath75 »

opless wrote: post #9

He's right about LeCun. Yann really does not like Deep Learning being criticized. Please someone who knows much more than me about deep learning tell me how a deep learning ai can explain how it came to an answer. It can't. By definition. You can say that it's a equation with a lot of terms, but that isn't really showing your working out. You need a symbolic system to show that working out. This isn't to say that dee…

Most people can’t explain why they make most of their decisions, really. It’s really only a very small subset of our activity that we are capable of explaining logically.

What’s the chain of reasoning behind me falling in love and marrying my wife? What’s the chain of reasoning behind why I watch the great British bake off compulsively? What’s the chain of reasoning that leads an alcoholic to drink time and time again. What’s the chain of reasoning behind why I look at a rainbow and see bands of distinct colors? What’s the chain of reasoning behind why I paused and scratched my nose just now?

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