Tuesday, January 31, 2012

Psychophysics and Consciousness

I reread this paper by David Chalmers yesterday morning for the first time in several years. I had been reminded of it because of this commentary by Kaspar Meyer in Science last week. The commentary was mildly interesting, and pointed out some of the current neuroscience perspectives as to just what consciousness is: e.g. is it the sensory experience with a background of knowledge and cognitive processes ("bottom up"), or is it a sort of best-estimate of what reality is given current and recent circumstances, using sensory input as a sort of reality check ("top down")? He finishes off in what seemed to me to be pretty fuzzy territory, but it was at least evocative of interesting ideas.

I'm vaguely familiar with some of this stuff, but I've never gotten too deep into because it doesn't satisfy me the way the philosophers do. The neuroscientists are looking for the "neural correlates of consciousness", which I guess is all that one really can look for. What this science reveals is the structure of consciousness, i.e. what is and is not included, what are the boundaries and how are they determined by the nature of the brain, and as indicated above, what exactly is the seeming 'core', or experiential reference point, of conscious experience, in neurobiological terms.

It is good stuff, but it always seems to me that the proposed theories far outstrip the basic science that is supposed to underpin them (e.g., in the commentary, Meyer cites experiments that demonstrate internally generated excitation of sensory cortex, and more generally recurrent activation, as evidence for the interesting idea that perceptual experience "would result from signals that descend through the sensory systems, just as behavior results from signals that descend along the motor pathways"). I don't know, that seems a bit of cart before horse, but like I said, I've only ever really skimmed the surface of this research. Meyer, Damasio, Dehaene, these guys are all basically frontal cortex cognitive neuroscientists, not perception scientists, and I've never really had cause to sink into that part of the science.

Now, the Chalmers paper. That's what I was going to go on about, not the Meyer commentary...

Anyways, in that paper Chalmers isn't really describing new ideas or new ways of thinking about consciousness (there is a subsection on some sort of "Kripkean" analysis of some philosophical point which I think actually subtracted from my comprehension of other parts of the paper, but it doesn't seem crucial). What he does is lay out a taxonomy of theories of consciousness - and the consciousness he's talking about isn't the "easy" kind, as he calls it, i.e. the NCC business that Dehaene is always going on about, but the "hard" kind, i.e. the fact-of-phenomenal-experience. I was thinking about that taxonomy yesterday evening, and wondering how psychophysics as a science fits into it, whether or not it biases one towards one or another way of thinking about phenomenal consciousness and just what it could be, or where it might come from.

As far as I know, the only visual psychophysicist who has written extensively (in English) on the philosophy of perception is Stanley Klein. I'm sure there are others, probably some I have heard of, but for now I'm guessing that if they exist they are writing in German or Italian. Klein is a proponent of the idea that phenomenal consciousness has something to do with quantum physics. Chalmers categorizes this sort of idea as dualist, since it supposes that consciousness is a quantum epiphenomenon of the activity of the physical brain. In other words, there is the brain and its physical structure, then there is a corresponding, consequent pattern or structure of quantum effects, and it is those effects that correspond to subjective, phenomenal consciousness.

I never liked this idea, at all. It usually relies on the Copenhagen interpretation of quantum mechanics to make the connection between observation and collapse of a wave function, which is the same thing that leads to that horrible Schrodinger's cat story. Not that I'm qualified to really have an opinion on this stuff, but that interpretation - that multiple possibilities exist simultaneously until selected by "observation" - is obviously nonsense, and just exists to show that something is not properly understood about the whole situation.

Okay, so I've shown myself to be a quantum mechanics ignoramus. Anyways, the QM-as-consciousness stuff is a type of dualism according to Chalmers, and I think it's quasi-mysticism, but does it have any currency among psychophysicists? I doubt it. I think Klein carries it because he was a student of Feynman who went into psychology, and he couldn't help but make the connection. He's an order of magnitude smarter than I am, maybe, but I think he's wrong.

As scientists, we might expect that psychophysicists should be materialists according to Chalmers' taxonomy. When I first got interested in perception and psychophysics was back when I was reading every bit of Daniel Dennett that I could find, and he is really the popular standard bearer of materialist theories of phenomenology (or was back in the 90's; this was the same time that I read Blackmore's "Meme Machine", and became completely obsessed with those ideas for a good couple of years). The idea here is that consciousness, in a way, doesn't actually exist; all that exists is the interconnected and multilayered and recurrent set of mechanisms for relating sensation to action over many timescales; in other words, "the mind is what the brain does". The fact that we have the impression of "looking out", or of being somehow spatially immersed in our thoughts and percepts, is a sort of necessary fiction that helps all those mechanisms to bind together and work correctly.

I'm not sure, but I think that J.J. Gibson might have been the closest thing (in the previous academic age) to a philosophical materialist in vision science. I suppose that most vision scientists adhere to a much more nuanced form of materialism, since Gibsonian materialism, or direct realism, is not really in good repute these days. I really like the idea in general, and consider it a good null hypothesis for study of perception - i.e. the perceptual world is the physical world that we tend naively to identify it with, and not a "representation" of the physical, and a given brain is a locus of limitations on what is known or remembered or simply accessible about this world.

Cognitive and perceptual neuroscience in general usually makes claims about consciousness that are consistent with the materialist position, i.e. that consciousness is the set of processes and functions of the brain. Chalmers says this (about neuroscience) explicitly. I always feel, though, (and I think that somewhere I've seen a talk by Dehaene where he says as much) that this is a terminological confusion, and that the neuroscientists must generally know, but forget sometimes, that the hard problem of consciousness, of phenomenology, is not addressed by their studies. Again, you know, I just have superficial acquaintance with this research, and maybe it's a common complaint amongst the Dehaenists that outsiders are always complaining that they (Dehaenists) are claiming that they're studying something that they aren't, when of course, duh, the Dehaenists know the difference. Oh well.

Finally, we wrap things up by mentioning what Chalmers calls monism, which is ultimately pan-psychism or pan-subjectivism. Reality has its relational, "objective" properties, and also its intrinsic, "subjective" properties. Phenomenal consciousness is simply the intrinsic nature of a functioning brain. This is an old idea, thousands of years old maybe, but it's not scientific. It's anti-scientific, even, since it's a claim that science, being the study of the objective nature of reality, can by definition not touch phenomenal consciousness. I think this is probably the truth of things, too, and it's kind of irritating. Anyways, is this a common feeling amongst psychophysicists, that the ultimate object of their study (whether or not they admit it; behaviorist materialism is a necessary stance for formulating good scientific theories of perception) is by definition un-attainable? That might be the answer right there; there's an operational stance (materialism), and a functional stance (monism), and only one of them - the wrong one - will ever get you anywhere.

I guess I'm going to have to start questioning psychophysicists. It will require a certain amount of drunkenness, I'm sure...

Wednesday, January 25, 2012

chinese american economics II

during this year's China trip, Jingping and I had a few discussions re the issue of $-元 exchange rate, and I noticed a few more points.

so, the Chinese state controls the international value of the RMB, for reasons including the cycle explained in that previous post. i didn't state there that there's a special factor making that cycle necessary, factor being that exchanges are only possible through government-controlled agencies (i.e. Chinese banks, which are all state-run). the Chinese state is slowly allowing the value of the RMB to appreciate, by a few percent a year over the past few years, because they recognize that the power of the Chinese economy has outstripped the exchange rate.

in other words, Chinese labor and land - i.e. export - is no longer as cheap and plentiful for foreigners as it used to be, and foreign labor and land - i.e. import - is no longer obviously prohibitively expensive. the Chinese don't want to damage their export system, and they don't want to get overwhelmed with a whole new system of imports, so they're making the RMB adjustment very, very slowly.

this isn't what I noticed, though. this trip, the topic of American investment kept coming up, especially in the context of wealthy Chinese sending their high school or college age children to study in the US. this must be barely affordable even for the upper-middle-class Chinese that are doing it, because private schools in the US are expensive even for Americans. the skewed exchange rate makes it even more expensive, probably by a factor of 2 or more.

on top of this, Jingping's parents gave us a good amount of money to use for her optometry school bills; this is money that they otherwise would have lent to people in China for a small return. they recognized that Jingping taking a large US loan ("financial aid") and paying a large amount of interest would be more costly than giving her the money and thereby giving up their Chinese interest. but, it's still a loss this way, because simply by moving the cash to the US and waiting any meaningful interval of time, the value of the money will decrease.

you can think about this more generally, and in bigger numbers. moderately wealthy Chinese, i.e. those just above Jingping's parents, have enough to invest in their child's education, accepting the exchange rate loss because, well, it's their child. but for the very wealthy - which in China often means state officials, investment abroad means business interests. wealthy Chinese own property abroad, have money in foreign accounts which they use to do international business. they do this because of the operational freedom it gives them, and because their profit margins must be larger than the decline in value of the foreign currencies (i.e. $$) they're using.

but if the drop were too fast... the foreign calculations wouldn't change, and business might actually pick up a bit if it had any connection to markets that were now becoming available to Chinese spending. but for the wealthy Chinese controlling those businesses, their domestic profits could drop precipitously. they might even lose money in the short term.

so, it's not just about protection of the Chinese export economy, or protection against foreign export economies; it's also about protection of domestic profits from profits on foreign investments.

Tuesday, January 24, 2012

Quote of the week, from a new PNAS paper (sorry for the Harvard link, but it's not like anyone actually will be clicking on that!) on using genetic manipulations to get silkworms to produce spider-like silk:

"Silkworms can be cultivated en masse, but territorialism and cannibalism preclude spider farming as a viable manufacturing approach."

Thursday, January 12, 2012

Priority Ranking

In another advance in procrastination, I have invented a method of ranking priorities of multiple projects. My primary reason for procrastination is still obscure, and we can just refer to it now by the shorthand term 'laziness'. However, I will maintain that important components of my procrastination include conflict between different projects, difficulty in efficiently organizing time, and inability to perceive in a useful or concrete way the relative priority of multiple alternative actions.

To address these three components, I decided simply to make a list of things which I have to work on, ranging from the immediate and obvious to the more wishful and distant. The list doesn't need to be deeply detailed, only superficially sketched, and it seems necessary that the different items should be mostly independent of one another. Having created this list, I then create a matrix of pairwise comparisons of priority of items in the list. The current list has twelve items, and so there are sixty-six comparisons to be made (twelve times twelve possible comparisons, minus the twelve identity comparisons, and then divided by two since order of comparison is assumed to be unimportant).

Each comparison is a rating on a three point scale. For each comparison, the following question is asked: "Given these two items (column, row), which is more important to work on right now?" If the first item has higher priority, the rating is 1.0; if the second item (i.e. not the first item), the rating is 0.0; if priority appears equivalent, the rating is 0.5. Below I've pasted in the current matrix. Only the values below the main diagonal are filled in; the main diagonal is null since these are meaningless comparisons, and the values above the main diagonal are automatically filled in as the inverse of the corresponding comparison below. Total priority for an item is simply the average over all rows for each column, and is shown in the leftmost column.

I think this system has potential! We'll see if it helps, and if I can keep up with it, updating it regularly. I haven't made up a scheme for what to do with projects that pass some sort of milestone; if a paper is finished (does that happen?), the item would probably just be removed from the list, while projects would transition to papers. There, I just made up a scheme!

Here's to organization!

Wednesday, January 11, 2012

design change

Look at the new design! I'm so excited. I'm going to post every day now, really.

We also have a new url, xuexixiangshang. This is the only configuration of 好好学习,天天向上 that worked as a valid prefix for blogger.com. It's a great slogan, and not quite as embarrassing as everyoneisdead, which belies that I didn't really expect this journal to last so long. Downside of changing the url is that my MS-WBT traffic is going to halt, though I guess eventually it will probably pick up again. Whatever!

Monday, January 09, 2012

Wuhu Environs

About five hundred kilometers upstream from the Pacific, the River runs east and then abruptly north. Sprawling eastward from the northern arm of this right angle is the City of Wuhu. The main body of the City is pressed up against the River, which is still the region's main artery for trade, though in turns railroads and now highways have added new arteries, enabling the City to sprawl away from the River in new directions, and to mix its influence with its neighbors.

To the south, the City begins to wrap around the River bend before it fades into farming villages and the occasional satellite towns that sit between and around the tips of the northernmost foothills of the Yellow Mountains. My wife was born in one of these towns, and her parents in another smaller one nearby, the two towns separated by a long fragment of those foothills, a little mountain with a northward spine. Her ancestors are buried on the slopes of that mountain.

Eastwards, there are marshes which have been engineered over centuries, or millennia, into networks of polders, surrounded by channels filled with water from distant rivers, on each of which sits a tiny village or a cluster of tended fields, or both. Some of these networks are regular, laid out in vast grids tens of kilometers across, showing from any vantage point the mark of some overarching plan, carried out long ago by the people of those marshes. Others follow no obvious pattern, except that there seems to be some average island size, similar to that constant size of the regular networks, and some acceptable deviation from this average, and an agreement amongst the people that they were going to reform the marshes into channels and islands.

Surrounded and out of options, the Hegemon Xiang Yu is said to have killed himself nearby, two-thousand two-hundred and fourteen years ago, and someone is supposed to have taken his horse's saddle up onto a mountain and buried it. That mountain gives its name to the City of Ma'anshan, which also presses up against the east bank of the River, fifty kilometers or so north of Wuhu. This City is known for making steel, and a ride through town will show you infinite smokestacks and gray air that covers everything, it is beautiful and terrible all at once.

Further north along the course of the River is the Southern Capital, and from there the River makes its final drive east where it breaks apart and becomes Shanghai. Across the River bend from Wuhu, north and west, is Chaohu, which has recently been dismembered by its neighboring Cities, most notably the provincial capital of Hefei, which sits even further along the same northwest vector.

Westwards, up the River, there is more, Hubei and Jiangxi and beyond, but there is more in every direction, and the mind follows the flow of the river back towards the Ocean in the east, and does not easily run against it, and these are enough reasons now to conclude and say that the City rules the neighborhood of that bend in the River.