One reason I like Stoicism

More posts are on the way. But, for now, a quick one.

I was thinking about one of my favorite quotes from the Stoic philosopher and Roman emperor Marcus Aurelius, when something occurred to me. I wonder if it'll occur to you too.

Marcus says:

"Say to yourself every morning, I shall meet with meddling, ungrateful, arrogant, deceitful, envious, churlish men. All these things happen to them because they are ignorant of good and evil. But I, who have seen that the nature of the good is beautiful, and of the bad is ugly, and that the nature of him who does wrong is akin to me, not only because we are of the same blood or seed, but because we participate in the same intelligence and the same portion of the divinity, I can neither be injured by any of them, for no one can fix on me what is ugly, nor can I be angry with my kinsmen, nor hate them. For we are made for co-operation, like feet, like hands, like eyelids, like the rows of the upper and lower teeth. To act against one another then is contrary to nature; and acting against one another is to be vexed and to turn away."


Here are some very minor modifications to that quote that occurred to me. There is nothing particularly systematic or rigorously philosophical here -- just a fanciful play with the quote, but one that conveys a very different religious and philosophical tone.

"Say to yourself every morning, I am a meddling, ungrateful, arrogant, deceitful, envious, churlish man. All these things happen to me because I am ignorant of good and evil. But you, who has seen that the nature of the good is beautiful, and of the bad is ugly, and that the nature of him who does wrong is akin to you, not only because you are of the same blood or seed, but because you participate in the same intelligence and the same portion of the divinity, you can neither be injured by me, for no one can fix on you what is ugly, nor can you be angry with me or my kinsmen, nor hate us. For we are made for co-operation, like feet, like hands, like eyelids, like the rows of the upper and lower teeth. To act against you then is contrary to nature; and acting against you is to be vexed and to turn away."

Now, when I considered the quote after doing this pronoun replacement, its Christianity completely caught me off-guard. It sounds to me like it could be a very profound and orthodox Christian prayer. Maybe this little play is completely silly and pointless, but it struck me also that this is precisely why I prefer Stoicism as a way of life to a religion like Christianity. Christianity would acknowledge all of the same power and ability, but consider it belonging to someone else -- to someone who one must prostrate before, and in some sense, beg from. Stoicism, in contrast, seems directly and enormously empowering -- you have all of these wonderful faculties, and you can and must choose daily to exercise them. I should note no specific anti-Christian bias here. Judaism, for example, seems not too far away from Christianity in advocating this sort of humble, prostrating, enervating kind of approach to daily life.

Does your brain balance prediction and observation?

Sorry for the slight infrequency in my posts. Things are hectic in graduate school, as can be expected. I do still plan to update this blog with thoughts as frequently as I can find time.

So I just watched a talk by Moshe Bar of the Harvard Medical School. The thrust of his research program is that the mind (and neural substrates thereof) do not passively respond to environmental stimuli, but constantly attempt to predict what is about to happen -- what the eyes are about to see happen next, for example. Or, if seeing a blurry outline of an object, inferring what that object is from contextual and shape cues. Bar showed very neat MEG evidence showing that the time course for activation of the (prefrontal) brain area supposed to do the prediction is about right for his hypothesis. In other words, it activates before the area associated more directly with conscious recognition of an object does. Curiously, this means that the prefrontal cortex is involved directly in fairly low level vision. This, in and of itself, is interesting data, and Bar's hypothesis seems plausible. But to my mind, it says too little about the cognitive mechanisms involved. Here is a proposal about what could be going on, from a computational perspective.

This all struck me as very similar to the AI mechanism known as a Kalman filter. Without getting into the math, the basic idea behind a Kalman filter is that it adjusts the balance between prediction and observation in the model of the world that the organism dynamically builds. So, for example, a Kalman-filter-equipped robot that is navigating a ship could rely either on observations of the nearby shoreline combined with the speed reported by its engines to calculate its predicted position in the future. Alternatively, it could rely on "dead reckoning" -- knowing that it left harbor in a particular location, and headed in a particular direction with a particular speed. Which one the robot wants to rely on depends on how noisy each set of information is. If, for example, the robot is in a deep fog where the shoreline is hard to make out, and the engine speed-reporting device is malfunctioning, relying on dead reckoning may be a good idea. If, on the other hand, there is a strong but unpredictable current in the water (say, the ship passed through some whirlpool and came out facing a slightly different direction), then the robot probably wants to rely much more on the shoreline and engine speed readings.

The Kalman filter plays a role in all this by calculating the (mathematically provably) optimal balance between which set of information to rely on (prediction or observation), dependent on the noise of each, such that the model is maximally accurate.

The point of all of this is -- could it be that the neural architecture Bar provides evidence for is actually a neural instantiation of the Kalman filter? One way to test for this might be to see if activation of the prefrontal "predictive" area Bar identifies is lessened when the environmental input is clearer, and strengthened when it is noisier. Of course, even if the neural system is some sort of instantiation of a Kalman-filter-like device, it would not have to behave in this way. Perhaps the prefrontal area Bar identified is just the prediction element of the Kalman filter design, with a further "selective" element being present, which performs the actual computation of determining how the organism should balance relying on prediction versus observation.

Making specific predictions is complicated in this case, but it might also be worthwhile. The idea of a computational mechanism originally proposed in AI being instantiated in neural architecture unites the two fields in a pretty exciting way, shows exactly the kind of thing AI has to contribute to the study of the mind, and might even suggest that we instantiate a computationally, mathematically, theoretically optimal (!!!) mechanism.

The really depressing thing about the Viriginia governor race

If you don't know the story, it's summarized here. Essentially, Republican gubernatorial candidate Bob McDonnell is taking some political flack for a thesis he wrote 20 years ago during his Masters program. The thesis contained many pieces of pretty old school right wing agenda. For example, McDoinnell wrote that working women and feminists are "detrimental" to the family and that government policy should favor married couples over "cohabitators, homosexuals or fornicators."

I won't talk much more about McDonnell -- you can find plenty of bloggers and news stories covering his thesis and the political situation. The part that gets to me is a little different than the political issue of his thesis. Rather, I can't believe CNN is calling his work a "research paper" (Eg. in the article linked above).

Lets be clear here. McDonnell's thesis was written at an unabashedly evangelical university, started by Pat Robertson to further a Christian right-wing social agenda. It was originally named Christian Broadcasting Network University (seriously), eponymous for Pat Robertson's TV network. Here's what The Washington Post has to say on the thesis:

'The thesis wasn't so much a case against government as a blueprint to change what he saw as a liberal model into one that actively promoted conservative, faith-based principles through tax policy, the public schools, welfare reform and other avenues.

He argued for covenant marriage, a legally distinct type of marriage intended to make it more difficult to obtain a divorce. He advocated character education programs in public schools to teach "traditional Judeo-Christian values" and other principles that he thought many youths were not learning in their homes. He called for less government encroachment on parental authority, for example, redefining child abuse to "exclude parental spanking." He lamented the "purging of religious influence" from public schools. And he criticized federal tax credits for child care expenditures because they encouraged women to enter the workforce.

"Further expenditures would be used to subsidize a dynamic new trend of working women and feminists that is ultimately detrimental to the family by entrenching status-quo of nonparental primary nurture of children," he wrote.'

That's what CNN considers research? As far as I can tell, McDonnell's thesis had nothing but public policy proposals in it. There was no research into anything. Do they have any idea how this makes people perceive real research? How am I, a scientist-in-training, supposed to ever be able to tell any layperson that I do "research" too, and expect them to understand that what I do is as different from McDonnell's thesis as any two pieces of academic work can be? Is it any wonder the average non-college-educated American thinks that science and Christian science are kinda sorta pretty much the same thing?

I guess I might be hyperbolizing, but I see this kind of minor, subtle slip-up, where academia isn't even the focus of the news article, to be much more detrimental to the dissemination of academic understanding to the public than bad science writing. This is so small that the average person won't notice it enough to really think about the claim that McDonnell conducted research. Where a bad summary of a real research finding in the scientific press can cause laypeople to question the value of a field of study or a particular finding, or may misinform them about the finding itself, it will at least cause them to engage with and think about it. This kind of sloppy writing, on the other hand, both reflects and reaffirms incorrect public opinion about academia mostly without being consciously acknowledged, let alone challenged.

A quick thought on euthanasia

This, to me, is a puzzle.

Why is euthanasia considered not only an acceptable, but indeed, the single most humane end-of-life procedure when it comes to animals, while evoking dread, hesitation, and often many prohibitory laws when it comes to humans?

I really have no idea. Thoughts?

Diachronic vs. synchronic explanations: Why psychology needs both

So I'm at Harvard now, and settling in fine. I don't have internet at home yet, so posting might be a little bit spotty until I do. Now, let's jump into it.

Steve Pinker's "How The Mind Works" is a pretty classic book at this point. New York Times bestseller, Pulitzer finalist, and one of the few real, undiluted and scientific psychology/cognitive science books to have made it into the public consciousness. Pinker wears somewhat different hats in each of his books, and in this one, he is a staunch evolutionary psychologist -- dismissing Lewontin and Gould's "spandrel" argument out of hand (and unconvincingly, in my view), and claiming that psychology must turn to evolution for answers to its important questions, How The Mind Works.

The philosopher and cognitive scientist Jerry Fodor wrote a book titled "The Mind Doesn't Work That Way", both an obvious jab at Pinker's lofty title, and a serious critique of his ideas. One of Fodor's chief arguments is against evolutionary psychology as a whole. The argument can be summarized like this:

How something came to be is a "diachronic" (across time) explanation, and how something is now is a "synchronic" (concurrent time) explanation. According to Fodor, diachronic and synchronic explanations are unrelated to each other, because they answer different questions. The former answers the question of "How X came to be" or "Why X is the way it is, and not some other way". The latter answers the question of "How X works". Furthermore, Fodor argues that the twain shall never meet. Diachronic investigations are, in principle, incapable of answering how something works, and synchronic explanations are, in principle, incapable of answering how something came to be.

An illustrative analogy is the study of flight and the building of airplanes. If you want to know how to build an airplane, you don't go to the museum and study the history of flight, tracing its progress and evolution from the Wright brothers on. You ask an engineer and get the blueprints for a real, functioning, modern airplane. If you don't have access to that sort of thing, and we don't when it comes to the mind, you try to reverse-engineer a modern airplane. The history of flight, in short, will not help you.

What this all means is if we want to know how the mind works, evolutionary explanations (which are diachronic) are unhelpful. If we want to know why the mind is the way it is, and not some other plausible way -- for example, when we've built a model that mimics a particular function, but doesn't seem to work the way the mind does, and we want to know why -- we can look into evolution. But if we want to know how the mind works in its present form, we need to study it directly. Good old psychology.

When I first heard about this argument, I wasn't just stumped, I was distraught. I'm not the biggest fan of evolutionary psychology, mainly because I think it has some serious problems in its execution and the methodology available to it. But neither am I willing to throw the whole enterprise out or concede that it's irrelevant. Before I had any good reason, I had a strong gut feeling that Fodor was wrong. The good reason took a couple of days.

Fodor's mistake is ignoring the real reason for the existence of evolutionary psychology: the way that something came to be constrains the range of possibilities for how it can be now. We may have the capacity to completely redesign an airplane if we discover a better way for it to be built, but evolution is famous for its inertia. As Pinker points out, the reason the male seminal ducts don't wind straight down, hooking around the ureter, is that our reptilian ancestors' testicles were inside their bodies, and when our bodies became too warm to produce semen and the testicles had to descend into the sack of their present form, evolution could not redesign the plumbing, and the seminal ducts got caught on the ureter "like a gardener who snags a hose around a tree".

Of course, in this case, we can simply look into a human male and see the design of the seminal ducts. The synchronic explanation is available to us. But imagine if it was not -- for example, if we lived in some universe where evolution had been discovered, but where, as in the middle ages, dissection of cadavers was forbidden and imaging technology did not exist. Wouldn't it help to know that our reptilian ancestor's testicles were inside their bodies, and that the ducts wound around the ureter? Wouldn't it help to know even more that non-human mammals, especially those who we share a close evolutionary ancestry with, and whose testicles did descend into an external sack have their ducts snagged on the ureter? Would it really remain unconvincing if we found this design in all mammals with descended testicles? Or would we then think it pretty likely that our bodies have the same design?

The issue is that, while synchronic explanations provide evidence through deductive reasoning, diachronic explanations are necessarily inductive. Barring extreme philosophical skepticism that would claim every bit of reasoning based on observation is inductive, if a dissection or an X-ray-type body image shows seminal ducts going around the ureter, then that is the direct conclusion we deductively draw from that information, coupled with our knowledge about the reliability of the technology used, its functioning, and the trustworthiness of our own senses. On the other hand, there is nothing as compelling about finding the snagged seminal ducts design in our closesy ape ancestors. It could be that some beneficial mutation did take place between them and us, so that the design of our male reproductive system is different. But the closer the ancestors where we find the same design, and the more the findings in other animals support the evolutionary hypothesis that predicts which animals will have the same design (that is, all of the ones with descended testicles that are known to have evolved from reptiles), the more confident we can be.

And in studying the mind, this is the kind of thing we have to do, because synchronic explanations are often unavailable. Medieval sensibilities aside, we simply don't have the tools to directly divine the exact design of our cognitive machinery (and that is still true, despite all recent advances in neuroimaging). Evolutionary psychology, if we are careful with it and remain mindful of its shortcomings, can provide inductive evidence about the design of some particular cognitive system, if we can more directly observe the antecedents of this design in creatures closely related to our own evolutionary ancestors of different times, and chart its evolutionary trajectory (what it looked like in fish, in reptiles, in mammals, in monkeys, in apes...) Evolutinary psychology isn't dead or useless. It might, however, be humbled. And given some of its more blatant trespasses in recent years, that's not a bad thing.

A short pause

I'm currently in the process of getting ready to move to Boston, so there are likely not going to be any new posts for about a week, because I just won't have time to sit and write anything thoughtful. I'll resume posting soon (as well as responding to the great comments on some of the previous posts), so check back in a bit!

Why I don't buy the Chinese Room

The Chinese Room is a thought experiment proposed by John Searle, meant to evoke intuitions that disprove the computational theory of mind (roughly, that the mind is a symbol-manipulating, somewhat computer-like machine). Let me summarize the argument quickly.

Imagine you have a person inside a room. The room has an input slot, through which the person receives cards with Chinese symbols written on them. The person takes the card over to a book, which has something like a dictionary of "if... then" commands. If the card received has symbol X printed on it, for example, the book will tell the person to output a card with symbol Y. The symbols that are outputted are precisely correct responses to the input symbols, also in Chinese. The person will then write symbol Y on a card, and proceed to push it out of the room through the output slot. In this way, it would be hypothetically possible to hold an entire conversation with the room.

The question is -- does the person in the room know Chinese? Searle's argument is that if the computational theory of mind is right, we would have to say yes -- after all, the room is doing what a good computer should. It has a vast memory with instructions on how to proceed (the book), a processor to manipulate the symbols (the person), but it seems intuitive that neither the person nor the entire room understands Chinese. Imagine the person memorizing the book -- the intuition doesn't seem to change. No Chinese understanding going on. For intuitive simplicity, I will refer to the Chinese Person from now on, meaning the person who's memorized the contents of the book. I think this modification (which Searle himself suggested, so I'm not weakening his point any) serves to clarify the intuition just a little.

There have been countless attempts to argue against the Chinese room, find a flaw in the logic, and save the computational theory. The reason for this post is that the problem I've seen in the Chinese room for a while is one I haven't seen mentioned in the criticisms of it. That's not to say it hasn't been pointed out -- I just haven't seen it. So maybe this will be new to some people who already know, and even those who know to hate, Searle's argument.

The problem as I see it is that the book has to be not only readable, but writeable. No proponent of the computational theory has ever suggested anything like a hard-coded read-only set of commands. No one, not even Fodor, who is the most extreme nativist I know of, thinks that we don't learn anything throughout our lifetime. The computational idea is that the mind processes new information into, in some very unspecified sense, a set of symbols, which then modify its internal thought processes, which in turn modify the outputs it produces. Being writeable fits into the other feature that the book must have -- it must provide outputs in a generative way. No computational theorist would ever propose to model the mind as a stock series of canned responses. The book must, in fact, be constantly changing the output symbol it's ready to provide to any given input, based on previous inputs it received, the contents in the book already, preformance limitations, etc.

I don't see a way Searle could include writeability and generativity into the Chinese room argument without causing the intuition to fall apart. Imagine a third component of the system -- a set of instructions for how to rewrite the memory book. A metabook. A person memorizing this, and the original book would seem to have what the computational theory requires, but perhaps still be unable to understand Chinese. But, of course, there'd have to be a set of instructions to rewrite the metabook. At some point, early or late, one of the metabooks would need to have instructions for rewriting itself.

I don't know about you, but my intuition falls apart here. At some point, if we have a Chinese Person who has memorized the original book and all its companion metabooks, so that the Person can start legitimate conversations in Chinese, respond appropriately in a context-sensitive way, constantly adjust responses based not only on the Chinese words themselves, but also the speaker they originated from, the context, the weather, and a myriad other possible factors, and learn from interactions in a way that affects future conversations, I'd probably be willing to ascribe knowledge of Chinese to the whole system, er... person.

Unless understanding has to involve consciousness. And there, of course, Searle has me (and everyone else). Really, though, at that point, the argument is identical to Chalmers' zombie argument. I have to concede that unless we figure out what makes us conscious, we're not going to build a human being. But that seems to me to be a different argument than the one Searle wants to run. If I understand him correctly, what he wants to show is something more like, no robot we build or computational explanation we give will ever be able to work the same way people work. And that doesn't seem to follow. It's entirely conceivable to me that we humans works just like the Chinese Person, with an added element of consciousness and qualia, for all we know about these. In the end, if Searle's argument comes down only to the point that a robot copy of a person may still be missing qualia, I'd be willing to agree with him. But I'm not sure that the computational theory of mind suffers any.