Monday, August 6, 2012

Consciousness, Information, and the Interpretation Problem

One of the greatest mysteries of modern science involves understanding the nature of consciousness. There are currently many competing theories for the origins of consciousness. Although a clear solution is not yet in sight, nevertheless, there are many things that I believe that we can say about the problem now.

Two competing popular theories of consciousness are Material Property Dualism (MPD), and Functional Property Dualism (FPD). Both FPD and MPD are a variety of Property Dualism, that claims that something "more" than the structure and dynamics of physics is needed to explain consciousness. MPD claims that consciousness is inescapably tied to the matter that makes up our brains, while FPD claims that it is only the functional properties of our minds that is important, and that a simulation of a brain on a computer would thus have the same subjective experiences as does the biological brain. Personally, I prefer neither of these camps, but instead subscribe to a form of Representational Functionalism (RF), that claims that nothing more than the structure and dynamics of physics is needed for consciousness. Nevertheless, I think that there is value in comparing the arguments for MPD with those for FPD, since I believe that there are compelling reasons to prefer FPD over MPD if one is forced to chose between these two theories.

A major criticism of the computational model of consciousness raised by Material Property Dualists, against both FPD and RF, is that all information must be "interpreted" before it could mean anything, or have qualia or consciousness, while Functional Property Dualists claim that it is the functional properties of the system that carries the dual properties that lead to consciousness. MPD posits that only matter can carry the "property" of consciousness, a "dual" property, beyond its causal properties, which form the structure and dynamics of physics. It is easy to understand why they feel this way. After all, why would nothing more than a bunch of ones and zeros have any subjective experience, no matter how much complexity is contained in the organization of the ones and zeros. This is all very intuitively pleasing. And a similar argument seems to show that the structure and dynamics of physics alone shouldn't lead to experience either. It should lead to all the behavior we have, including our claims to experience, but (these people argue) one can imagine all that structure and dynamics taking place like the wheels of a clock, completely absent any subjective experience. RF, which I prefer, responds to this criticism by claiming that nothing "more" than the structure and dynamics of physics is actually needed, even though it intuitively feels like something more is needed (our intuitions are wrong). In contrast, FPD gets around this argument by admitting that something "more" is indeed needed, but they tie the "more" to the information/functional properties of the system instead of to the matter. Supporters of MPD usually respond to this argument by claiming that the information in the functional system needs something to help "interpret" it correctly, and that the ones and zeros by themselves are simply random bits of information, with no proper interpretation, and thus, with no experience. Thus, they claim that the "more" must reside in the fundamental properties of matter in some way.

On the surface, these arguments seem to be quite compelling. However, the Maxwell's Demon thought experiment, indicates something strange. We know from relativity that we can turn matter into energy and  vice versa. But now we also know that we can also convert INFORMATION into matter or energy and vice versaThis has important implications for the whole consciousness debate between MPD and FPD. 

Why? Because it seems to mean that the universe is made of something fundamental, namely matter / energy / information, and that these three things are nothing more than three different manifestations of the same fundamental entity. Much as water, steam, and ice are all different manifestations of the same fundamental entity. Thus, if matter can carry some "fundamental" interpretation that allows consciousness (as MPD claims), then so can information (as FPD claims). And there is no reason to suppose that matter is any "better" at carrying this fundamental property that allows for the interpretation of experience than is information. Therefore, inasmuch as the single objection to FPD (proper interpretation) has been removed, and there are compelling reasons to prefer FPD over MPD (we haven't found any evidence of specific materials that perform this function in the brain, and David Chalmer's "fading qualia" and "dancing qualia" thought experiments STRONGLY indicate that consciousness must be found in the functional aspects of the brain, not in its material properties), it seems that we should all now prefer FPD over MPD.

This observation doesn't say much about the continuing debate between Representational Functionalism (RF) and FPD, (where I strongly prefer RF for reasons related to the epiphenomenalism argument). However, it does indicate that MPD should largely be removed from consideration as a potential solution to the problem of consciousness. The remaining debate must largely be between Functional Property Dualism and Representational Functionalism. 

Tuesday, April 24, 2012

The Essentials of Epistemology

The Essentials of Epistemology (the study of how to discover the truth):

Now we See Through a Glass, Darkly
Now we See Through a Glass, Darkly
How can we tell the difference between truth and error, between fact and fiction, between conspiracy fact and conspiracy theory? Naturally, the best solution is to become an expert. But unfortunately you can't become an expert without first learning what information to trust, and what information to ignore. Furthermore, it is impossible for everyone to be experts on everything. So we all eventually have to trust the advice of others. But whose advice should we trust? These questions are becoming increasingly important in the world of the internet, where everyone has been given a printing press, and where false (and even dangerous) ideas spread like wildfire. 

I do research in statistics, which is the study of how to determine truth from data and make rational decisions based upon this data. So I naturally have some opinions on the matter. But explaining these principles to others outside the field of statistics can be a challenge. And it is not reasonable to expect everyone to get a degree in statistics before they try to sort through the difference between truth and error. 

So, how should the average person determine truth from error? There is no magical approach that will guarantee that you are never deceived or mistaken. But I believe that there are a few simple principles that will lead you to the truth more often than other approaches. They are: 

1. Simplicity: The simplest theory is to be preferred over the more complex theory, all other things being equal (which has bearing on #4 as well).

2. Data over Dogmatism (be willing to change your mind): Let the data speak for itself as much as possible, don't assume that the answer must match some ideological or dogmatic assumption. Be as dispassionate and rational as possible. Allow your opinions to change when the data contradicts your initial opinions.

3. Avoid Confirmation Bias: People naturally tend to seek out data that confirms their initial opinions (this is called confirmation bias), while reacting to new data that contradicts their original belief with even more fervent adherence to the original belief (the backfire effect). This means that the luck of the draw for what you believed first has an unfair advantage. Therefore, be sure to actively look for data that contradicts your initial opinions, and do your very very best, as hard as it can be, to treat such new data fairly. (Conservatives should watch PBS, CNN, and BBC, while liberals should watch Fox News). It is only after you have read and understood the opinions of those that disagree with you, that you can be confident that you are actually right. 

4. Avoid Conspiracy Theories: Although real conspiracies do exist (usually very small ones), assuming that all data counter to your initial belief is due to a vast conspiracy to hide the truth is problematic, because first, it vastly over simplifies the reality where each person has their own (often contradictory) goals and motivations, which generally limits the real conspiracies in size and scope; second, most people want to do good, and those that do evil usually do it because they have convinced themselves that it is the right thing to do; and third (and most important) it creates a situation where your opinion (right or wrong), can never be contradicted by evidence, no matter how strong or otherwise convincing. This is an especially dangerous flavor of confirmation bias (see #3 above).

5. Trust the Experts: Because we can't personally experience everything, we must trust the opinions of others that have experienced things that we have not. Assuming that white elephants don't exist because you haven't seen one is foolish if others have. Thus, a large percentage of our understanding of the world around us must be based upon the witness and opinions of others. Our task is often to determine which witnesses to believe, and which opinions to trust.  When deciding which experts to believe, always assign more weight to the opinions of people who know more about the subject, than you do to people who know less about the subject. This means that we should trust and respect the experts in their fields. Look for issues and ideas where there is a strong consensus among the experts in a given field. And be careful of internet sources. Some 60 year old guy blogging in his underwear from his parent's basement does not a reliable expert make.

I understand that most human progress was made when people like Galileo challenged expert views on things like whether the earth was at the center of the solar system. But Galileo also understood that challenging this consensus required careful study and very strong evidence. He then went out and did the difficult legwork to gather, summarize, present, publish, and then defend that evidence. And when he did, the consensus gradually changed. It is possible (and necessary) to occasionally challenge a consensus view, but it should require strong evidence first. To think that we know better than the vast majority of those around us without that very strong threshold of both effort and evidence is one important definition of pride.

6. Look for General but not Unanimous Consensus: Understand that there will always be a few dissenting voices on every issue. Don't assume that because you found a PhD physicist that thinks that the earth is flat that there is "controversy" among the scientific community on the issue, and that there is no scientific consensus on the matter, or think that the idea that the earth is a sphere is "only a theory", or that you should "teach the controversy" on this matter. Instead, look for general agreement among some large majority of the experts. 

7. Avoid Anecdotes and Emotional Stories: Anecdotes are almost entirely useless, since there will always be an anecdote or two that seems to support any possible position that one could conceivably hold. Unfortunately, these anecdotal stories often have vast emotional impact, but that doesn't mean that they are right. Instead, look for broad statistically significant studies to find truth. They are less emotionally convincing, but they are far more likely to be right!

If you follow these 7 rules, you will undoubtedly be wrong on occasion. But you will be wrong less often than if you don't, and you will be willing to change your mind rapidly when more information showing that you were wrong becomes available. If you do this, you will be unlikely to be lead astray, and you will be far more likely to discover things as they really are, really were, and really will be. 

So, how does that play out?

In the vaccination debate, it means that we should pay more attention to reputable doctors than we do to Jenny McCarthy when talking about whether we should vaccinate. It means that while the emotional story of the child that died after being vaccinated may be more emotionally moving, it should not be as intellectually convincing as a broad based statistical study. And it means that we shouldn't be surprised to find a few MD's in both camps. But we should look at the broad consensus, and realize that the vast majority of reputable doctors favor vaccination. Therefore we should favor vaccination. There is no vast conspiracy to make vaccination look successful when it is not. Sure the pharmaceutical companies have the motivation to do this, but the vast array of doctors who care about their patients don't. At least not in a way that could cause this level of near universal support.

How would these principles play out in the global warming debate? I am sure you can immediately see the answer. How about evolution? Again, is the answer obvious? How about economics? For some economic issues, things are a bit more muddled, but that itself is a conclusion, namely that there is consensus on some important points, but disagreement on some others.We should likely be uncertain ourselves when it comes to the areas of expert disagreement. It is remarkably prideful to assume that we know for certain answers to controversial questions that so many other very intelligent people don't.

What about the truthers? The birthers? Opposition to GMOs? And the list goes on and on and on.

(For more thoughts on the 'wisdom of the crowd,' the 'marketplace of ideas' and the problems the internet has produced in these things, see my paper: "Amplifying the Wisdom of the Crowd, Building and Measuring for Expert and Moral Consensus" by myself and Brent Allsop.)

Tuesday, January 17, 2012

The Singularity May not be Near, but You Have Yet to Convince Me

I would like to take a moment to respond briefly to Michael Shermer's fascinating article: "In the Year 9595, why the Singularity is not Near, but Hope Springs Eternal" in Scientific American, January 2012.

Michael Shermer's rebuff of singularitarianism is witty and Interesting, but ultimately un-convincing. He makes fun of those who make predictions as "soothsayer's", but he seems to be ignoring the power of trends to often accurately predict future technological performance. His "baloney-detection alarm" may go off, but he provides no counter data. I prefer a data driven approach myself, and this article, witty as it was, was certainly not data driven. If the data says that this generation is most likely special, then it most likely is, Copenhagen principle or no.

Of course, trends don't always continue. But if they don't, in this case, I will be extremely interested in knowing why not, and it was this question that was never really addressed by Michael Shermer. For example, many people have argued that computational performance trends will not continue because we will hit the quantum limits of Moore's Law by 2015-2025. At least that would be a reasonable, although ultimately flawed, argument to make. But Shermer doesn't even do that. If he had, then he might have given me more to refute. For example, then I might have been able to discuss the fact that the human brain is a proof by example that it is possible to perform about 10^19 CPS for about 20 Watts, in a few cubic feet of space IF one is willing to change the architecture of the computer system from today's Von Neumann architecture to something more massively parallel. Which means that Moore's Law may stumble to a halt, but that there is plenty of room for computational improvement after the death of Moore's Law. Of course, progress down this new route may well follow a different trend, improving at a different speed. Progress may even slow for a time after the death of Moore's Law while we face up to the fact that we must switch directions before improvement can continue. But even if this is the case, since we are set to pass the upper bound for performing a full neural simulation of the human brain by 2025, Moore's Law will ultimately fail too late to stop the creation of the hardware needed for true AI.

Shermer did provide one data point, namely that knowing the wiring diagram of the nervous system of Caenorhabditis elegans, and having sufficiently powerful hardware to perform a full neural simulation has so far not lead to a working brain simulation of Caenorhabditis elegans. This is indeed an interesting data point. However, we appear to be making exponential progress at understanding the behavior of individual neurons, AND exponential progress at understanding the wiring diagrams of the brains of ever more complex organisms. Both. I argue that ONCE we thoroughly understand the behavior of individual neurons (and their many types/kinds, connections, and plasticity) THEN knowing the wiring diagram of ANY complexity is enough for full brain simulation. This is important to point out, because some singularitarians seem to think that once we have the wiring diagrams for human brains, and once we have the computational raw power, fully human level AI is inevitable. This is not true by any means. If computer trends continue, we will have the computational power to run a full neural level brain simulation by about 2025 in our super computers. But that doesn't mean that we will have the human connection diagram by that time, nor does it mean that we will have cracked the neuron by that time. However, we ARE making exponential progress on both fronts, so if we don't have these things by 2025, I would guess that we will have them by 2045... give or take 25 years or so either way. There is a lot of uncertainty there, mostly because we don't yet know exactly how complex the problem will be (the neural level modeling I mean, we have a descent idea about the other). Furthermore, the power to do the simulations will feed back on our neural understanding. We can plug one neural model into the simulation, and see how it runs, then compare to a real brain scan, and then tweak the simulation... rinse... repeat.... etc.

Essentially, I think that this man's skepticism is unfounded, or, at least, if it is founded, he failed miserably to explain why it is founded, or to be convincing in any meaningful way.