trentmkelly/LessWrong-43k huggingface dataset:
Brains more complicated than previously thought
by NancyLebovitz — 2011-02-18T15:37:45.506Z

Neurons aren't simple little machines, axons talk to each other.

He and his colleagues first discovered individual nerve cells can fire off signals even in the absence of electrical stimulations in the cell body or dendrites. It's not always stimulus in, immediate action potential out. (Action potentials are the fundamental electrical signaling elements used by neurons; they are very brief changes in the membrane voltage of the neuron.)

"This cellular memory is a novelty," Spruston said. "The neuron is responding to the history of what happened to it in the minute or so before." Spruston and Sheffield found that the cellular memory is stored in the axon and the action potential is generated farther down the axon than they would have expected. Instead of being near the cell body it occurs toward the end of the axon.

Their studies of individual neurons (from the hippocampus and neocortex of mice) led to experiments with multiple neurons, which resulted in perhaps the biggest surprise of all. The researchers found that one axon can talk to another. They stimulated one neuron, and detected the persistent firing in the other unstimulated neuron.

No dendrites or cell bodies were involved in this communication. "The axons are talking to each other, but it's a complete mystery as to how it works," Spruston said. "The next big question is: how widespread is this behavior? Is this an oddity or does in happen in lots of neurons? We don't think it's rare, so it's important for us to understand under what conditions it occurs and how this happens."

The original article (paywall).

Assuming this is all true, how does it affect the feasibility of uploading? Anyone want to bet on whether things are even more complicated than the current discoveries?

ETA: It seems unlikely to me that you have to simulate every atom to upload a person, and more unlikely that it's enough to view neurons as binary switches. Is there any good way to think about how much abstraction you can get away with in uploading?

Yes, I know it's a vague standard. I'm not sure how good an upload needs to be. How good would be good enough for you?
Dead men tell tales: falling out of love with SIA
by Stuart_Armstrong — 2011-02-18T14:10:04.187Z

SIA is the Self Indication Assumption, an anthropic theory about how we should reason about the universe given that we exist. I used to love it; the argument that I've found most convincing about SIA was the one I presented in this post. Recently, I've been falling out of love with SIA, and moving more towards a UDT version of anthropics (objective probabilities and total impact of your decision being of a specific type, including in all copies of you and enemies with the same decision process). So it's time I revisit my old post, and find the hole.

The argument rested on the plausible sounding assumption that creating extra copies and killing them is no different from if they hadn't existed in the first place. More precisely, it rested on the assumption that if I was told "You are not one of the agents I am about to talk about. Extra copies were created to be destroyed," it was exactly the same as hearing "Extra copies were created to be destroyed. And you're not one of them."

But I realised that from the UDT/TDT perspective, there is a great difference between the two situations, if I have the time to update decisions in the course of the sentence. Consider the following three scenarios:

Scenario 1 (SIA):

Two agents are created, then one is destroyed with 50% probability. Each living agent is entirely selfish, with utility linear in money, and the dead agent gets nothing. Every survivor will be presented with the same bet. Then you should take the SIA 2:1 odds that you are in the world with two agents. This is the scenario I was assuming.

Scenario 2 (SSA):

Two agents are created, then one is destroyed with 50% probability. Each living agent is entirely selfish, with utility linear in money, and the dead agent is altruistic towards his survivor. This is similar to my initial intuition in this post. Note that every agents have the same utility: "as long as I live, I care about myself, but after I die, I'll care about the other guy", so you can't distinguish them based on their utility. As before, every survivor will be presented with the same bet.

Here, once you have been told the scenario, but before knowing whether anyone has been killed, you should pre-commit to taking 1:1 odds that you are in the world with two agents. And in UDT/TDT precommitting is the same as making the decision.

Scenario 3 (reverse SIA):

Same as before, except the dead agent...
Scholarship and DIY Science
by  — 2011-02-18T06:37:00.025Z

Related: Science: do it yourself, Some Heuristics for Evaluating The Soundness of the Academic Mainstream in Unfamiliar Fields, The Neglected Virtue of Scholarship

There's been some recent discussion about the value of answering your questions by reading the established scholarly literature in a field. On the one hand, if you never read other researchers' work, you'll be trying to invent the wheel, and you may well get things very wrong. The best way to learn physics is to pick up a physics textbook, not to try to deduce the laws of nature on your own. On the other hand, sometimes the leading scientists are wrong. Or sometimes you have a question that has never been studied scientifically. It's not always enough just to look at what the experts say; sometimes you need a little independent thought, or even the "DIY science" approach of looking at the data yourself and drawing your own conclusions. Ideally, these two approaches aren't really rivals, they're complementary. "DIY science" gives you insights into how to conduct scholarship -- what resources to seek out, and what claims to trust.

Looking up other people's research is scholarship, not science. Scholarship isn't bad. In most fields scholarship is useful, and in technical fields it's a prerequisite to doing science. But scholarship has its drawbacks. If there is no high-quality body of scientific research on a question (say, "How do people get very rich?") then looking up "expert" opinion isn't especially useful. And if there is a body of scientific research, but you have reason to suspect that the scientific community isn't well-informed or evenhanded, then you can't just rely on "experts." But you don't want to be mindlessly contrarian either. You need some independent way to evaluate whom to believe.

Take a topic like global warming. Is the scientific literature accurate? Well, I don't know. To know the answer, I'd have to know more about geophysics myself, be able to assess the data myself, and compare my "DIY science" to the experts and see if they match. Or, I'd have to know something about the trustworthiness of peer-reviewed scientific studies in general -- how likely they are to be true or false -- and use that data to inform how much I trust climate scientists. Either way, to have good evidence to believe...
Why can’t a man be more like a woman?
by KatjaGrace — 2011-02-18T03:31:33.000Z

Women are often encouraged to move into male dominated activities, such as engineering. This is not because overall interest in engineering appears to be lacking, but because women’s interest seems to be less than men’s. This is arguably for cultural reasons, so it is argued that culture is inhibiting women from pursuing careers that they may be otherwise suited to and happy with.

If the symptom is that women do less engineering than men, why do we always encourage women to do more engineering, rather than encouraging men to do less? It seems we think men are presently endowed with the perfect level of engineering interest, and women should feel the same, but are impaired by culture.

This could make sense. For instance, perhaps all humans somehow naturally have the socially optimal level of engineering interest, but then insidious cultural influences eat away those interests in women. I think this is roughly how many people model the situation.

This model seems unlikely to be anywhere near the truth. Culture is packed with influences. These influences are not specific to inhibiting women’s impulses to do supposedly masculine things. They tell everyone what sort of people engineers are supposed to be, how much respect a person will get for technical abilities, how much respect they get for wealth, which interests will be taken to indicate the personal qualities they wish to express, which personal qualities are good to express, which cities are most attractive to live in, etc etc etc. Everyone’s level of inclination to be an engineer is significantly composed of cultural influences.

A cacophony of cultural influences may somehow culminate in a socially optimum level of interest in engineering of course. But it is hard to believe that some spectacular invisible mechanism orchestrates this perfect equilibrium for all cultural influences, except those that are gender specific. If there are fleets of rogue cultural influences sabotaging women’s inclinations, this must cast suspicion on the optimality of all other less infamous cultural influences.

Besides the incredible unlikelihood that all cultural influences except gender related ones culminate in a socially optimal level of interest in a given activity, it just doesn’t look like that’s what’s going on. Socially optimal cultural influences would mainly correct for ext...
Strong substrate independence: a thing that goes wrong in my mind when exposed to philosophy
by HonoreDB — 2011-02-18T01:40:18.733Z

Certain kinds of philosophy and speculative fiction, including kinds that get discussed here all the time, tend to cause a ridiculous thing to happen: I start doubting the difference between existence and non-existence. This bothers me, because it's clearly a useless dead end. Can anyone help with this?

The two concepts that tend to do it for me are

* Substrate independence/strong AI: The idea that a simulation of my mind is still me. That I could survive the process of uploading myself into a computer running Windows, a cellular automaton run by this guy, or even something that didn't look like a computer, mind, or universe at all to anyone in the outside world. That we could potentially create or discover a simulated universe that we could have ethical obligations towards. This is all pretty intuitive to me and largely accepted by the sort of people who think about these things.

* Multiverses: The idea that the world is bigger than the universe.

My typical line of thought goes something like this: suppose I run a Turing Machine that encodes a universe containing conscious beings. That universe now exists as a simulation within my own. It's just as real as mine, just more precarious because events in my reality can mess with its substrate. If I died and nobody knew how it worked, it would still be real (so I should make provisions for that scenario). Okay, but Turing Machines are simple. A Turing Machine simulating a coherent universe containing conscious beings can probably arise naturally, by chance. In that case, those beings are still real even if nobody on the outside, looking at the substrate, realizes what they're looking at. Okay, but now consider Turing Machines like John Conway's Fractran, which are encoded into an ordered set of rational numbers and run by multiplication. I think it's fair to say that rational numbers and multiplication occur naturally, everywhere. Arithmetic lives everywhere. But furthermore, arithmetic lives *nowhere*. It's not just substrate-independent; it's independent of whether or not there is a substrate. 2+2=4 no matter whether two bottlecaps are being combined with two other bottlecaps to make four bottlecaps. So every Turing-computable reality already exists to the extent that math itself does.

I think this is stupid....
Writing reviews instead of collecting
by DSimon — 2011-02-17T23:27:02.898Z

I have a problem with developing attachments to the books, movies, games, and other media that I enjoy. For example, after I finished playing the new Prince of Persia title via rental, I enjoyed it so much that I went out and bought my own copy, even though I knew I would be unlikely to play the game again for at least a year.

This is wasteful in a lot of ways. The media takes up unnecessary space, and makes moving from one place to another more difficult; the last time I moved, easily 3/4 the boxes contained media, primarily books which have especially low information-to-weight and information-to-volume ratios.

More importantly, my magpie habit uses up money, even though there are numerous free or inexpensive long-term rental services like NetFlix, GameFly, and my old favorite the US public library system.

I've decided to get around this by trying to transfer my sense of ownership from the item itself to the memory of the experience of enjoying it. So, I've been writing up reviews of all the games, movies, and books that I own, and also all those that I can remember enjoying in the past even if I don't currently own them. I want this "collection" to feel complete, so that I'm not tempted to go and spend $40 on some old SNES cartridge for the sake of posterity, or to buy any more books that I'm not actually expecting to read often enough or on short notice enough to offset the tiny cost of going down to the library and checking it out when needed.

I've been trying to look around for some computer application or net service that can help me do this, but to my surprise, pickings have been pretty slim! The only one that seems vaguely close is blippr, which exhibits a number of good ideas:

Keeps reviews limited to a very short length (140 characters), allowing me to write reviews more quickly by preventing me from descending into essay-length epic poems describing the many admirable qualities of The Blues Brothers or whatever.

Allows you to add new media to the system, and update descriptions for existing media. It's particularly smart about finding box art for new items.

I can easily see a list of the items I've reviewed, with thumbnail images of boxart, greatly contributing to the "this is my stuff" feeling that I'm aiming for. The fact that it's online, and so I could therefore give somebody a link to my list and "show off", also helps that feeling (though I'm u

...
Recursively Self-Improving Human Intelligence
by curiousepic — 2011-02-17T21:55:04.743Z

There's plenty of discussion about recursive self-improvement for AGIs, and self-improvement for ourselves, but I haven't come across (in memory) anything that specifically combines the two concepts. Arguably, increasing rationality skills would be recursive, but can anyone think of specific ways in which we can improve ourselves via iterative cycles? Is there a limit to how far we can currently improve our abilities by improving our abilities to improve our abilities? Or are these not the right questions; the concept a mere semantic illusion...

A place to start might be base-level anti-akrasia abilities. Are there physical steps we can do to force ourselves to self-improve when we otherwise lose the will or forget or move on to another interesting subject? Construct some sort of externally self-propelling regime that pulls us along a path to improvement? Could we "Incept" ourselves with the seed of a recursively self-improving paradigm?

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Forgive the overbearingly inquisitive tone. This is my first post after lurking a couple years, and I guess even in the discussion section I subconsciously avoid making any potentially low-status claims of my own!
Revisiting the anthropic trilemma III: solutions and interpretations
by Stuart_Armstrong — 2011-02-17T15:14:59.790Z

In previous posts, I revisited Eliezer's anthropic trilemma, approaching it with ata's perspective that the decisions made are the objects of fundamental interest, not the probabilities or processes that gave rise to them. I initially applied my naive intuitions to the problem, and got nonsense. I then constructed a small collection of reasonable-seeming assumptions, and showed they defined a single method of spreading utility functions across copies.

This post will apply that method to the anthropic trilemma, and thus give us the "right" decisions to make. I'll then try and interpret these decisions, and see what they tell us about subjective anticipation, probabilities and the impact of decisions. As in the original post, I will be using the chocolate bar as the unit of indexical utility, as it is a well known fact that everyone's utility is linear in chocolate.

The details of the lottery winning setup can be found either here or here. The decisions I must make are:

Would I give up a chocolate bar now for two to be given to one of the copies if I win the lottery? No, this loses me one utility and gains me only 2/million.

Would I give up a chocolate bar now for two to given to every copy if I win the lottery? Yes, this loses me one utility and gains me 2*trillion/million = 2 million.

Would I give up one chocolate bar now, for two chocolate bars to the future merged me if I win the lottery? No, this gives me an expected utility of -1+2/million.

Now let it be after the lottery draw, after the possible duplication, but before I know whether I've won the lottery or not. Would I give up one chocolate bar now in exchange for two for me, if I had won the lottery (assume this deal is offered to everyone)? The SIA odds say that I should; I have an expected gain of 1999/1001 ≈ 2.

Now assume that I have been told I've won the lottery, so I'm one of the trillion duplicates. Would I give up a chocolate bar for the future merged copy having two? Yes, I would, the utility gain is 2-1=1.

So those are the decisions; how to interpret them? There are several ways of doing this. There are four things to keep in mind: probability, decision impact, utility function, and subjective anticipation.

SIA, individual impact, standard utility function

The way I've phrased the system uses the SIA probabilities, and an individual impact (I don't need to worry about my other copies are dec...
Sleeping anti-beauty and the presumptuous philosopher
by Stuart_Armstrong — 2011-02-17T14:59:59.055Z

My approach for dividing utility between copies gives the usual and expected solutions to the sleeping beauty problem: if all copies are offered bets, take 1/3 odds, if only one copy is offered bets, take 1/2 odds.

This makes sense, because my approach is analogous to "some future version of Sleeping Beauty gets to keep all the profits".

The presumptuous philosopher problem is subtly different from the sleeping beauty problem. It can best be phrased as sleeping beauty problem where each copy doesn't care for any other copy. Solving this is a bit more subtle, but an useful half-way point is the "Sleeping Anti-Beauty" problem.

Here, as before, one or two copies are created depending on the result of a coin flip. However, if two copies are created, they are the reverse of mutually altruistic: they derive disutility from the other copy achieving its utility. So if both copies receive $1, neither of their utilities increase: they are happy to have the cash, but angry the other copy also has cash.

Apart from this difference in indexical utility, the two copies are identical, and will reach the same decision. Now, as before, every copy is approached with bets on whether they are in the large universe (with two copies) or the small one (with a single copy). Using standard UDT/TDT Newcomb-problem type reasoning, they will always take the small universe side in any bet (as any gain/loss in the large universe is compensated for by the same gain/loss for the other copy they dislike).

Now, you could model the presumptuous philosopher by saying they have 50% chance of being in a Sleeping-Beauty (SB) situation and 50% of being in a Sleeping Anti-Beauty (SAB) situation (indifference modelled as half way between altruism and hate).

There are 4 equally likely possibilities here: small universe in SB, large universe in SB, small universe in SAB, large universe in SAB. A contract that gives $1 in a small universe is worth 0.25 + 0 + 0.25 + 0 = $0.5. While a contract that gives $1 in a large universe is worth 0 + 0.25*2 + 0 + 0 = $0.5 (as long as its offered to everyone). So it seems that a presumptuous philosopher should take even odds on the size of the universe if he doesn't care about the other presumptuous philosophers.

It's no coincidence this result can be reached by UDT-like arguments such as "take the objective probabilities of the universes, and consider the total impact of y...
Computer security story
by Perplexed — 2011-02-17T00:26:49.184Z

NPR has this story:
The hacktivist group Anonymous is at it again. This time, it has humiliated an Internet security firm that threatened to out the group's hierarchy.
If you remember, Anonymous has been in the news, first, because in support of WikiLeaks, it undertook cyberattacks that brought down the websites of Visa and Mastercard. Second, because it brought down the sites of some government entities in Egypt and helped the anti-government protesters with technical help. Third, because as NPR's Martin Kaste reported, the FBI is hot on the group's heels.
Today, the website ArsTechnica ran a piece that details how Anonymous methodically went after HBGary Federal's digital infrastructure. Earlier this month, HBGary Federal's CEO Aaron Barr said the company, which specializes in analyzing vulnerabilities in computer security for companies and even some government agencies, had undertaken an investigation of Anonymous and had used social media to unmask the group's most important people.
Barr said an HBGary representative was set to give a presentation at a security conference in San Francisco, but as soon as Anonymous got wind of their plans, it hacked into HBGary's servers, rifled through their e-mails and published them to the web. The group defaced HBGary's website and published the user registration database of another site owned by Greg Hoglund, owner of HBGary.
Amazingly, reports ArsTechnica, Anonymous managed all this by exploiting, easy and everyday security flaws. ...
If even professional security firms are this vulnerable, I hate to think what will happen when the cyber war really starts.
Overcoming the negative signal of not attending college.
by James_Miller — 2011-02-16T20:13:12.500Z

The signaling view of college holds that graduates of elite colleges earn high average salaries not because of what they learned in school but rather because top colleges select for students who have highly valued traits, the two most important probably being high IQ and strong work ethic. Since in rich countries almost every smart, hard working person attends college not going to college sends a loud negative signal to potential employers. Elite colleges, of course, are fantastically expensive signaling devices.

Although I teach at an elite college I have a proposal for an alternate much less expensive and probably even more accurate signaling mechanism. An organization could have a one month program which only admits those who get a high score on the SATs or some other intelligence test. Then the entire program would consist of spending sixteen hours a day solving by hand simple addition and subtraction problems. The point of the program would be to show that its graduates can spend a huge amount of time doing extremely boring tasks with high accuracy. Graduating from the program would signal that you had both a high IQ and strong work ethic.

If the program had a reputation for graduating valuable employees then I suspect it would become desirable to many recent high school graduates. The challenge would be for the program to initially earn its reputation. Perhaps it could accomplish this by having some well-known backers, by giving big cash grants to its first few graduates or by promising the first few graduates attractive jobs such as at the SIAI.