You write "Eliezer made a very interesting claim-- that current hardware is sufficient for AI. Details?"
I don't know what argument Eliezer would've been using to reach that conclusion, but it's the kind of conclusion people typically reach if they do a Fermi estimate. E.g., take some bit of nervous tissue whose function seems to be pretty well understood, like the early visual preprocessing (edge detection, motion detection...) in the retina. Now estimate how much it would cost to build conventional silicon computer hardware performing the same operations; then scale the estimated cost of the brain in proportion to the ratio of volume of nervous tissue.
See http://boingboing.net/2009/02/10/hans-moravecs-slide.html for the conclusion of one popular version of this kind of analysis. I'm pretty sure that the analysis behind that slide is in at least one of Moravec's books (where the slide, or something similar to it, appears as an illustration), but I don't know offhand which book.
The analysis could be grossly wrong if the foundations are wrong, perhaps because key neurons are doing much more than we think. E.g., if some kind of neuron is storing a huge number of memory bits per neuron (which I doubt: admittedly there is no fundamental reason I know of that this couldn't be true, but there's also no evidence for it that I know of) or if neurons are doing quantum calculation (which seems exceedingly unlikely to me; and it is also unclear that quantum calculation can even help much with general intelligence, as opposed to helping with a few special classes of problems related to number theory). I don't know any particularly likely for way the foundations to be grossly wrong, though, so the conclusions seem pretty reasonable to me.
Note also that suitably specialized computer hardware tends to have something like an order of magnitude better price/performance than the general-purpose computer systems which appear on the graph. (E.g., it is much more cost-effective to render computer graphics using a specialized graphics board, rather than using software running on a general-purpose computer board.)
I find this line of argument pretty convincing, so I think it's a pretty good bet that given the software, current technology could build human-comparable AI hardware in quantity 100 for less than a million dollars per AI; and that if the figure isn't yet as low as one hundred thousand dollars per AI, it will be that low very soon.
Thanks. I'm not sure how much complexity is added by the dendrites making new connections.
Reply to: A "Failure to Evaluate Return-on-Time" Fallacy
Lionhearted writes:
Why will a randomly chosen eight-year-old fail a calculus test? Because most possible answers are wrong, and there is no force to guide him to the correct answers. (There is no need to postulate a “fear of success”; most ways writing or not writing on a calculus test constitute failure, and so people, and rocks, fail calculus tests by default.)
Why do most of us, most of the time, choose to "pursue our goals" through routes that are far less effective than the routes we could find if we tried?[1] My guess is that here, as with the calculus test, the main problem is that most courses of action are extremely ineffective, and that there has been no strong evolutionary or cultural force sufficient to focus us on the very narrow behavior patterns that would actually be effective.
To be more specific: there are clearly at least some limited senses in which we have goals. We: (1) tell ourselves and others stories of how we’re aiming for various “goals”; (2) search out modes of activity that are consistent with the role, and goal-seeking, that we see ourselves as doing (“learning math”; “becoming a comedian”; “being a good parent”); and sometimes even (3) feel glad or disappointed when we do/don’t achieve our “goals”.
But there are clearly also heuristics that would be useful to goal-achievement (or that would be part of what it means to “have goals” at all) that we do not automatically carry out. We do not automatically:
.... or carry out any number of other useful techniques. Instead, we mostly just do things. We act from habit; we act from impulse or convenience when primed by the activities in front of us; we remember our goal and choose an action that feels associated with our goal. We do any number of things. But we do not systematically choose the narrow sets of actions that would effectively optimize for our claimed goals, or for any other goals.
Why? Most basically, because humans are only just on the cusp of general intelligence. Perhaps 5% of the population has enough abstract reasoning skill to verbally understand that the above heuristics would be useful once these heuristics are pointed out. That is not at all the same as the ability to automatically implement these heuristics. Our verbal, conversational systems are much better at abstract reasoning than are the motivational systems that pull our behavior. I have enough abstract reasoning ability to understand that I’m safe on the glass floor of a tall building, or that ice cream is not healthy, or that exercise furthers my goals... but this doesn’t lead to an automatic updating of the reward gradients that, absent rare and costly conscious overrides, pull my behavior. I can train my automatic systems, for example by visualizing ice cream as disgusting and artery-clogging and yucky, or by walking across the glass floor often enough to persuade my brain that I can’t fall through the floor... but systematically training one’s motivational systems in this way is also not automatic for us. And so it seems far from surprising that most of us have not trained ourselves in this way, and that most of our “goal-seeking” actions are far less effective than they could be.
Still, I’m keen to train. I know people who are far more strategic than I am, and there seem to be clear avenues for becoming far more strategic than they are. It also seems that having goals, in a much more pervasive sense than (1)-(3), is part of what “rational” should mean, will help us achieve what we care about, and hasn't been taught in much detail on LW.
So, to second Lionhearted's questions: does this analysis seem right? Have some of you trained yourselves to be substantially more strategic, or goal-achieving, than you started out? How did you do it? Do you agree with (a)-(h) above? Do you have some good heuristics to add? Do you have some good ideas for how to train yourself in such heuristics?
[1] For example, why do many people go through long training programs “to make money” without spending a few hours doing salary comparisons ahead of time? Why do many who type for hours a day remain two-finger typists, without bothering with a typing tutor program? Why do people spend their Saturdays “enjoying themselves” without bothering to track which of their habitual leisure activities are *actually* enjoyable? Why do even unusually numerate people fear illness, car accidents, and bogeymen, and take safety measures, but not bother to look up statistics on the relative risks? Why do most of us settle into a single, stereotyped mode of studying, writing, social interaction, or the like, without trying alternatives to see if they work better -- even when such experiments as we have tried have sometimes given great boosts?