Regular visitors to The Splintered Mind will know I usually post on a MWF schedule. No post this Friday, though: I'm heading up to Oregon tomorrow for my sister's wedding! I should be back in the saddle on Monday.
Wednesday, September 27, 2006
Johann Purkinje [Jan Purkyne] was a leading figure in early 19th century physiology, and his descriptions of visual experience were discussed extensively by late 19th century introspective psychologists. However, I haven't been able to find English translations of his work. In connnection with my recent thoughts on our visual experience with our eyes closed, I was particularly intrigued by the respectful citations of his work on this topic by introspective psychologists such as Hermann Helmholtz and E.B. Titchener. So I decided to struggle through some Purkinje in German. In the Underblog, I've posted amateurish translations of a few passages.
A few points of interest about the translated passages:
(1.) Purkinje claims to see a chessboard pattern of squares when his eyes are closed and he's facing toward the sun (as well as in many other conditions). He claims that this experience "was noticed by most individuals with whom I made the experiments" -- so much so that he thinks it must derive from general conditions in the human organism. Yet I don't seem to have such an experience in those conditions; nor has anyone in any condition, whom I've asked about visual experience with their eyes closed, reported such a chessboard pattern to me.
(2.) He makes an interesting point about the difficulty in finding the borderpoint of the visual field with the eyes closed (cf. my post on the limits of the visual field with respect to nasal-side phosphenes).
(3.) The portrayals of afterimages (with the exception of what is now called the "Purkinje afterimage") are two-dimensional -- a point about which he is fairly explicit in Section XXVIII (cf. my post on whether images are flat).
Posted by Eric Schwitzgebel at 8:33 AM
Monday, September 25, 2006
"Phantom limb" phenomena have been well-known since at least the time of Descartes. People with missing limbs will report feeling sensations in the missing areas. In 1998, V.S. Ramachandran famously showed that people with missing arms can sometimes be induced to feel phantom sensations (as though in their missing hands) if gently stroked on the face. (See this article, for example, which is rich with interesting descriptions.) The reason for this, evidently, is that as the nerves from the phantom limb area provide no useful input, other nearby regions of the brain begin to recruit neurons from the areas formerly dedicated to input from the phantom limb; and the primary cortical region associated with tactile input from the face is adjacent to that associated with tactile input from the hand. Apparently, plasticity in input can sometimes outrun plasticity in the felt sensation, so that the relevant neurons that used to respond to stimulus from the hand and trigger (appropriately) a sensation subjectively located in the hand can come to respond to stimulus from the face while still triggering (now inappropriately) a sensation subjectively located in the hand.
Recent research -- for example by Peter Hickmott here at UC Riverside -- has shown that in animals whose nerves have been cut, one can start seeing neural plasticity within minutues. Cortical neurons near the border between forepaw and jaw which formerly acted in synchrony with other forepaw neurons start to act in synchrony with the jaw neurons.
This leads me to think of the following experiment. If we somehow induced in people cortical input from the hand similar to that one would get from denervation of the hand (by sensory deprivation? by anaesthesia?), and then one gently stroked the jaw, a la Ramachandran, might the person report a sensation in the hand?
If this has been done, I haven't heard of it.
Posted by Eric Schwitzgebel at 8:45 AM
Friday, September 22, 2006
Okay, here’s another post about the spatial properties (or not) of visual images. I seem to be on a kick!
Pete Mandik reminded me of this issue when he said something in his comments on my last post that seemed (perhaps only seemed?) to imply that he regarded images as generally two-dimensional.
We certainly talk, sometimes, as though they are. Most tellingly, I think, we call images “pictures” (in the mind’s eye), not (say) “sculptures”. Stephen Kosslyn, in his seminal 1980 book on imagery, describes the imagery space as “roughly circular” and compares its horizontal and vertical dimensions. He does not (that I recall) discuss its depth. Likewise, he says that position in the imagery matrix can be indicated by a pair of co-ordinates (polar co-ordinates r and theta) – not, as would be necessary for a three-dimensional imagery space, a triplet of co-ordinates (such as the Cartesian x,y,z or the polar r, theta, and phi). His sample portrayals of images never indicate depth.
In my posts here and here and my article on the question of whether things look flat, I suggest that our tendency to think of circular objects viewed obliquely as “looking elliptical” and distant objects as “looking small” derives primarily from an over-analogizing of visual experience to flat media such as paintings and pictures. I won’t rehearse those arguments again; but if that’s right, then perhaps our (at least some of our) tendency to think of images as flat derives from a similar over-analogizing and should be treated with similar skepticism.
One can accept that images are often (or even typically?) three-dimensional without going so far as to say that we can imagine something from multiple perspectives at once -- just as we can say that our visual representations and visual experience are fundamentally and ineliminably marked out in three-dimensional space (even monocularly) without saying that we can see from more than one angle at once.
So I’m wary of our too easily supposing that our imagery appears as if on a flat plane. But maybe, nonetheless, it does. I wonder about readers' introspective sense of this; and I’d be interested to hear also if you have reflections on neuroscientific or behavioral tests that might shine light on the question.
Posted by Eric Schwitzgebel at 7:20 AM
Wednesday, September 20, 2006
Here's another question about imagery experience -- related to Monday's post about whether images have subjective location. Can people (at least some people, in some circumstances) imagine things from multiple angles at once? Francis Galton, in his seminal study of imagery experience (1880, 1907), says that some of the best imagers report being about to do this. Jorge Luis Borges describes a similar phenomenon in a fictional character obsessed with a coin he calls a "Zahir":
There was a time when I could visualize the obverse, and then the reverse. Now I see them simultaneously. This is not as though the Zahir were crystal, because it is not a matter of one face being superimposed upon another; rather, it is as though my eyesight were spherical, with the Zahir in the center.
Now is this really possible? I can't claim ever to have had such an imagery experience myself; but that doesn't mean others can't do it. On the other hand, I don't think we should simply take people at their word when they make unusual claims about their experiential lives.
Here are two reasons one might think multiple-angle imagery is impossible:
(1.) If images are located in subjective space, as some people report -- say, near your forehead -- then it seems natural to suppose (if not strictly implied) that we have a single visual angle on those images, presumably the angle from the center of one's subjective self to the image in question. (Now that I see these words in print, though, I must say there seems to me something a little fishy in them!)
(2.) If images are instantiated in the brain (or caused by the brain) in accord with some topography of either subjective or objective space (e.g., the right side of the image is created by this location in the brain, the left side by this other location), then that topography may well require a single visual angle or point of view (e.g., in "circular vision" right and left might not be well defined).
I don't mean to say that either of these points is decisive -- not by a long shot. I wonder: Have any readers of this blog have had experiences they would describe as imagery from more than one angle simultaneously?
Posted by Eric Schwitzgebel at 8:22 AM
Monday, September 18, 2006
I've interviewed a number of people about their imagery. Some I've asked to form images as we speak; others I've had wear random beepers during their normal daily activity, and they're reported having imagery at the "sampled" moments when the beep goes off. Interestingly, some people report that their images have a spatial location -- typically near their foreheads or some small distance directly in front of their foreheads (up to a couple feet) -- while others deny that their images are located in subjective space in this way: Neither in their heads, nor in front of their heads, nor anywhere else.
Now I wonder: Are these differing reports to be trusted? Do some people experience their imagery as located in subjective space, while others do not? Or is one or the other, or both, of the groups confused in some way?
Although I'm not especially optimistic about definitively answering that question, here's at least one thought about how, in principle, it might be testable. Maybe imagery interacts to some extent with vision. If you imagine something in some particular region of space you might be worse (or better) at seeing external objects in that region. If so, then maybe people whose imagery is subjectively located will have enhanced or diminished performance in perceptual tasks in regions of space associated with their imagery, while they are maintaining an image, compared to regions of space outside their usual imagery field; and not so for those who report imagery as having no subjective location.
Posted by Eric Schwitzgebel at 8:26 AM
Friday, September 15, 2006
We commonly explain habitual patterns of action by appeal to people’s degree self-esteem. For example if your friend, call her Jane, keeps dating people who treat her poorly and someone asks you why, you might say she has low self-esteem. But what does it mean to say that someone has a low level of esteem for his or her self?
Taken literally, self-esteem seems to suggest believing that one's character and/or achievements are praiseworthy – that one has done well and, perhaps, can take credit for having done so. But Jane might be very successful in a number of departments of her life – she is doing well at her career, has many friends, material security, etc. If asked, she might say that all of these things are accomplishments that she can take credit for. But she can believe that and still suffer from “low self-esteem” and date people who are bad for her.
So what is self-esteem if it is not belief that one has done things that deserve praise?
One possibility is that esteem is like love – you can believe you have reason to love someone, but not actually feel it, and you can believe you have reason to esteem yourself, but not feel it. But even if self-esteem does involve feeling in addition to belief, I doubt that this solves our problem, because counterexamples cases seem to exist. For example: Jane believes she has reason to think well of herself, and feels positive when she thinks of herself and her accomplishments, but she still engages in the imprudent behavior – entering into relationships that are bad for her.
A second possibility is that the term ‘self-esteem’ is misleading; it is respect, not esteem, she is missing. To make this suggestion work we need an explanation of what self-respect – respect for one’s self – amounts to. Although it is initially appealing, I have doubts about this too. It is plausible to assume that a failure to respect X to be a failure to have the attitude towards X that one is obligated to have and that talk of obligation implies that the person in question is able to adopt do what they are obligated to do at will (by choice); and these assumptions imply that Jane could choose to respect herself (at will). But this casts doubt on the claim that her imprudence is explained by a failure of self-respect: part of the tragic thing about people like Jane, to whom we attribute low self-esteem, is that they often cannot solve their problem simply by choosing to (i.e. at will).
A final, third possibility, is that what we have in mind is Jane’s lack of self-concern. On this view, Jane would likely refrain from acting so imprudently if she cared more about her own well-being. If so we should stop talking about low self-esteem and talk about a lack of self-concern instead.
I am myself tempted to take that final approach and to stop talking of low self-esteem. Is this right? And do I need to fatten my diet of examples before drawing this general conclusion; are there other cases that allow us to make better sense of talk of low self-esteem?
Wednesday, September 13, 2006
When I close my eyes, and I'm not looking toward a bright light, I'm tempted to say I see black -- or, more accurately, an assortment of colors (afterimages?) on a largely black background. (See this post for a broader discussion of what we experience when our eyes are closed.)
But here's something that shakes my confidence: When I put my hands over my eyes (without pressing), it seems to get considerably darker. When I then remove my hands, I'm inclined to think (a.) that I'm having pretty much the same visual experience as when I originally closed my eyes, and (b.) that experience is one of middle gray, or -- since that doesn't seem quite right, either -- at least something too bright to be black.
Now it seems to me that either I was wrong in my first judgment that I was seeing (largely) black, or I'm wrong in (a) or (b).
The fact that the experience gets blacker with the hands over the eyes does not, it seems to me, compel the conclusion that it wasn't black in the first instance. My jeans are black, but my desk is definitely quite a bit blacker. Does this necessarily imply that my jeans are really only gray? And my desk is shiny. It reflects the beige floor tiles, in places, in a way that really is rather bright. That doesn't seem incompatible with its also being a perceivably black object; but is my visual experience as I look at that patch of the black desk also a visual experience of blackness? -- not just an experience of a black object, but involving "black(-ish) phenomenology" itself? Hm! I worry that there's something objectionably simplistic in that question, though I can't quite put my finger on it.
Coming back to my visual experience with my eyes closed, some of these same questions and confusions arise.
But -- you might have thought -- what could be simpler than recognizing an experience of blackness? Aren't judgments about one's current visual phenomenology of a field of color exactly the kind of thing that many philosophers have thought it's impossible to be mistaken about?
Posted by Eric Schwitzgebel at 9:18 AM
Monday, September 11, 2006
Although I am not a Theist, I have always found Jesus’s sayings
thought-provoking. Consider his take on judging others:
“Judge not, that ye be not judged. For with what judgment you judge,
you will be judged; and with the measure you use, it will be measured
back to you. And why do you look at the speck in your brother's eye,
but do not consider the plank in your own eye? Or how can you say to
your brother, 'Let me remove the speck from your eye'; and look, a
plank is in your own eye? Hypocrite!”
Jesus is clearly denouncing our tendency to judge others. But what
is his argument to that effect? And how should we understand the
warning about being judged ourselves?
One interpretation is as follows: if we judge another person against
some standard, S, and offer to correct them or help them improve when
they are judged to be lacking, then we will be judged against S too
(perhaps at the last judgment).
But even if it is true, does it give us reason to refrain from
judging others? I do not think so.
In some cases it clearly does not: I judge students in my logic class
- I measure their performance against a standard - and try to “remove
the specks” from their thinking, and I do this knowing that I still
make errors that are just like theirs. But, the possibility of
having my own thinking judged by the same standard is no reason to
refrain from my practice; in fact, I hope to make this possibility
actual by helping my students understand standards of sound
reasoning! I judge my students in part to help them develop their
own capacities to judge.
Analogous considerations seem to apply in the ethical realm. Ben
Franklin reports in his Biography that a Quaker friend told him he
(Franklin) was commonly thought proud, and that led Franklin to add
humility to the list of virtues he was trying to keep in mind and
develop. I do not see why the fact that the friend's own level of
pride (or humility) would be judged, would count against his judging
Franklin. And I do not think the appropriateness of his judging
Franklin depends on whether he was himself proud or even had many bad
traits. After all, people who are working to overcome serious
problems of their own are often better at noticing more subtle
shortcomings in others; having a plank in your own eye can make you
more attentive to speck in your brother’s eye, so why not tell him
about it and help him get it out of there?
Consequently, on this first reading (a second one will be considered
in the next post), I can’t agree with what Jesus says: I think we
should go ahead and judge each other and say to each other, ‘Let me
remove the speck from your eye’ even if maybe especially if we
have a plank in our own eye. By judging each other, we can hope to
become a bit more self-aware and clear-sighted.
Friday, September 08, 2006
One thing I think I'll always remember from Robert Jay Lifton 's excellent book, The Nazi Doctors -- though not the only thing -- is the ease with which I found myself able to sympathize with certain aspects of the Nazi mindset, the "Nazi biomedical vision" as Lifton calls it.
The Nazis (and some others!) gave eugenics a bad name, and few openly embrace eugenics today. Yet eugenics had many eminent supporters in the late 19th and early 20th centuries, and it's easy to see how people could be attracted to the idea of humanity taking control over its genetic pool and implementing eugenic measures designed to ensure that future generations are healthier, more intelligent, and of better moral character.
The view that racial differences are genetically important and that the races differ significantly in their intellectual and moral capacities has a similar history, involving some of the same figures. Like eugenics, the position had numerous eminent adherents in the 19th and early 20th centuries, only to become a political hot potato in the second half of the 20th century.
Both positions are of course abhorrent; let's take this as common ground. But I don't think they are obviously abhorrent. And it is that last fact to which I want to call your attention. In the current political climate, mainstream and liberal thinkers reflexively dismiss these views without, perhaps, appreciating their potential attractiveness to reasonable people in the right frame of mind and the right cultural context -- frames of mind and cultural contexts not too different from our own.
And of course, if you combine these two opinions (and certain views about the division and character of the races), one can come startlingly close to seeing merit in Nazi policy. In a Malthusian world, one might think it a moral duty to open up Lebensraum ("living space", i.e., new territory) for the genetically superior; given limited resources, one might think it best to trim away poor, and potentially genetically corrupting, stock. Evil can acquire the look of a moral imperative. If the heart rebels (as the ancient Chinese philosopher Mencius, one of my favorite moral psychologists, thinks it will), one might interpret that rebellion as misplaced compassion -- or at least compassion that should not be acted on, like the compassion that judges must sometimes set aside in delivering appropriately hard sentences.
That evil can disguise itself as reason is of course not news; but I think it salutary to remind ourselves sometimes how easily it can do so. Our ordinary, lazy habits of thinking tend to exaggerate the distance between ourselves and those we condemn.
Starvation as a method of killing was a logical extension of the frequent imagery of mental patients as "useless eaters." As a passive means of death, it was one more element of general neglect. In many places, mentally ill patients had already been fed insufficiently; and the idea of not nourishing them was "in the air" (p. 98).
and (you may wish to skip the following quote if you are easily upset):
I remember the gist of the following general remarks by Pfannmueller: These creatures (he meant the children) naturally represent for me as a National Socialist only a burden for the healthy body of the Volk. We do not kill (he could have here used a euphemistic expression for this word kill) with poison, injections, etc.; then the foreign press and certain gentlemen in Switzerland would only have new inflammatory material. No our method is much simpler and more natural, as you see. With these words, he pulled, with the help of a ... nurse, a child from its little bed. While he then exhibited the child like a dead rabbit, he asserted with a knowing expression and a cynical grin: For this one it will take two to three more days. The picture of this fat, grinning man, in his fleshy hand the wimpering skeleton, surrounded by other starving children, is still vivid in my mind (p. 62).
There are different kinds of evil -- evil in passion, evil in neglect -- but it is this cold evil, rigorously rationalized, whose shadowy potential in myself frightens me most.
Posted by Eric Schwitzgebel at 8:39 AM
Wednesday, September 06, 2006
Consider this stock problem case for Utilitarians: if a judge frames an innocent person and has him killed in order to placate a violent mob, he will produce better overall results than if he refuses to do so.
Assuming the Utilitarian thinks we should choose to do whatever maximizes utility, he has to bite the bullet and condone the framing, which is a blatant injustice and therefore wrong.
To avoid condoning framing the innocent, many Utilitarians adopt forms of indirect Utilitarianism, according to which utility will not be maximized if people consciously aim to maximize it; they claim that utility will be maximized when people, including judges, don’t (directly) aim to bring about that result. We might defend this shift by appeal to a general methodological principle: when an ethical theory conflicts with an intuition that all reasonable people share, the theory needs to yield to the intuition. On this view, then, all reasonable people share the intuition that framing the innocent is an injustice and therefore wrong. But is that true?
In a forthcoming paper (available here), John Doris and Alexandra Plakias raise doubts about that very claim by citing empirical evidence that the anti-framing intuition is a parochial artifact of Western culture. More specifically, they appeal to a study (which is forthcoming) that contrasts the intuitions of, “Americans of predominantly European descent and Chinese living in the People’s Republic of China,” and suggests that people in China are more likely to have pro-framing intuitions. Doris and Plakias suggest that the variability of intuitions (if it exists) is evidence for a surprising conclusion: the intuition that framing an innocent is unjust and wrong is something about which reasonable people can disagree.
Now even assuming that the empirical claim about cultural variability is true, one might resist the suggestion about reasonable disagreement on the grounds that the relevant Easterners -- Chinese living in the PRC -- have distorted intuitions. The most promising argument to this effect is that some background theory or value conception has distorted the intuitions. One possibility that Doris and Plakias mention is the collectivist conception of self that some attribute to Easterners. Other possibilities include Marxist theories and more traditional value conceptions (e.g. Buddhism, Taoism, Confucianism).
One thing to do, I suppose, would be to by running the study in other Eastern countries that do not have the history of Marxist rule or the same traditional value conceptions. But it is also important to ask whether any of these background theories or value conceptions would actually (purport to) support, or have been thought to support, the pro-framing intuition. One question here is about whether a conception claims to support the intuition that framing and killing an innocent is not wrong; the other is about whether people who endorse the conception have in fact avowed the intuition. For example some Japanese Zen Buddhists endorsed Japanese militarism, but that does not show that a Zen Buddhist conception would support militarism or war.
So I am wondering:
(1) Are there Chinese philosophers who explicitly discuss cases or issues like this and come down one way or the other?
(2) Would the Communist ideology promulgated in China support framing an innocent to placate a mob? Has it been taken that way in China or elsewhere?
(3) What is a collectivist conception of self and would it support pro-framing intuitions?
Monday, September 04, 2006
Raise a finger to about four inches in front of your nose. Focus on some object in the distance, then -- without changing your focus -- shift your attention back to your finger. Does it seem doubled? Most people claim to be able to experience this, at least after a few tries.
If you then focus carefully on your finger (bringing it out maybe to six or eight inches, depending on how close in you're able to bring your focus), do the objects in the far distance seem unfocused, blurry? Even doubled? Reports of doubling in this case are less common, but I think I can get some doubling in myself in this condition.
One of the great geniuses of the 19th century, a pivotal figure in physics and physiology and psychology, Hermann von Helmholtz writes:
When a person's attention is directed for the first time to the double images in binocular vision, he is usually greatly astonished to think that he had never noticed them before, especially when he reflects that the only objects he has ever seen single were those few that happened at the moment to be about as far from his eyes as the point of fixation. The great majority of objects, comprising all those that were farther or nearer than this point, were all seen double (1910/1962, III.7).
The eminent 18th-century philosopher Thomas Reid writes:
We find that when the eyes are sound and perfect, and the axes of both directed to one point, an object placed in that point is seen single.... Other objects at the same distance from the eyes as that to which their axes are directed do also appear single.... Objects which are much nearer to the eyes, or much more distant from them, than that to which the two eyes are directed, appear double. Thus, if the candle is placed at the distance of ten feet, and I hold my finger at arms-length between my eyes and the candle; when I look at the candle, I see my finger double; and when I look at my finger, I see the candle double: and the same thing happens with regard to all other objects at like distances which fall within the sphere of vision.... You may find a man that can say with good conscience, that he never saw things double all his life; yet this very man, put in the situation above mentioned, with his finger between him and candle, and desired to attend to the appearance of the object which he does not look at, will, upon the first trial, see the candle double, when he looks at his finger; and his finger double, when he looks at the candle. Does he now see otherwise than he saw before? No, surely; but he now attends to what he never attended to before. The same double appearance of an object hath been a thousand times presented to his eye before now; but he did not attend to it; and so it is as little an object of his reflection and memory, as if it had never happened (1764/1997, p. 133-134).
E.B. Titchener, the leading American introspective psychologist circa 1900 (second in eminence only to William James), writes:
The field of vision … shows a good deal of doubling: the tip of the cigar in your mouth splits into two, the edge of the open door wavers into two, the ropes of the swing, the telegraph pole, the stem of another, nearer tree, all are doubled. So long, that is, as the eyes are at rest, only certain objects in the field are seen single; the rest are seen double.... Our habitual disregard ot double images is one of the curiosities of binocular vision (1910, p. 309).
I assume most people now would not agree with such claims.
What's going on? Are these guys, despite their reputations -- and despite Helmholtz's and Titchener's many subtle and interesting introspective discoveries -- simply bad introspectors? I can barely get any doubling, I think, except in the most extreme conditions. I focus on the bookshelf four feet away; the door handle ten feet away seems not at all doubled. Have they unwittingly trained themselves to see double? If so, do they really see most things double, most of the time?
Maybe, I -- we? -- are the bad introspectors? Yet I find it very difficult to imagine that I'm wrong about the singular appearance of that doorknob....
Posted by Eric Schwitzgebel at 8:50 AM
Friday, September 01, 2006
I had a friend in high school, let’s call him Randy the Rebel, who was proud to have never read any of the assigned books for any of his English classes. I remember one break during college when he said he was no longer proud of that - he realized his pride had been foolish because not reading the books was nothing to be proud of.
This raises an interesting question: what should we, and what should we not, be proud of?
In thinking about this it is useful distinguish between two reasons we might have for saying that someone’s pride is foolish. The first is that the person is proud of something morally or ethically objectionable. The Nazi guard’s pride in having killed more prisoners than any other is foolish, and itself immoral, because nothing immoral is something to be proud of. But, as Justin D’Arms and Daniel Jacobson have argued, we may also criticize someone’s pride simply because it is inappropriate; some things are nothing to be proud of even though they are not immoral. Take, for example, my friend Randy’s “feat” of not reading the assigned books.
But what, then, makes something an appropriate object of pride? What does Randy’s “feat” lack?
One suggestion, built on Phillipa Foot's comments in her paper “Moral Beliefs” is as follows: in order to be an appropriate object of pride a thing must (1) belong to the person who is proud of it and (2) provide the person with some advantage or be an achievement. On this view, Randy’s pride was inappropriate because not having read the books was not really much of an achievement and provided him with no overall advantage. Personally, I like this but lean towards making the advantage bit a necessary condition; I think it is foolish to be proud of something that is not good for you.
D’Arms and Jacobson have recently objected to this account by appeal to the example of a sports fan. Consider a fan who is proud of the Buccaneers. On Foot’s view, this seems inappropriate because the team is not something that belongs to the fan. Or so D’Arms and Jacobson claim. On the contrary, I think that when we say that a fan is proud of his team, we really mean that she is proud to be a fan of a winning team, and that *is* something that belongs to her.
But even if that response works, I have to admit that on my view being a sports fan, even of a winning team, is not much to be proud of because it is not much of an achievement (it is mostly luck) and gives you only a minimal advantage (bragging rights, maybe the spoils from an office pool, etc.) I think it is foolish to be proud of your favorite team’s accomplishments.