Unreal Nature

June 30, 2009

That Strange Manic Courtship

Filed under: Uncategorized — unrealnature @ 7:31 am

The following is Myriam Weisang Misrach’s description of her husband, photographer Richard Misrach, at work (taken from Aperture 146):

It’s been ten years now of this adventure, joining Richard in his travels to remarkable sites — the postapocalyptic landscape of Bravo 20; the carnage of the dead animal pits; the Edenic glory of the desert empty of humans save for the two of us. But what stands out most is the photographer’s dance, that strange manic courtship between man and fading light, head swiveling under the cloth, camera roving up-and-down and side-to-side like some blind beast sniffing the air, then head reemerging, eyes wild, hair in knots and peaks, film holder in, slide out, thumb bearing down, seconds counted out — one-one thousand, two-one thousand, three . . . — then the whole thing in reverse, then running back to the van for more film, shouting with joy as he speeds by, “Can you believe this light? Oh God, I’ve never seen anything like that,” the same exclamation each time, over the many years. The same glee.

That is a perfect description of photographing with a view camera. Especially the bit about the hair … (and the joy). If you’re curious about Misrach, here is a pretty good 1996 article about him from the Los Angeles Times. [ link ]

-Julie

http://www.unrealnature.com/

Expectoration

Filed under: Uncategorized — unrealnature @ 7:26 am

 

Silverfish
by Robert Siegel

It lives in the damps of rejection,
  in the dark drain, feeding upon the effluvia
    of what we are, of what we’ve already been.

Everything comes down to this: we are its living —
  the fallen hair, the fingernail, the grease from a pore,
    used toothpaste, a detritus of whiskers and dead skin.

All this comes down and worries it into life,
  its body soft as lymph, a living expectoration,
    a glorified rheum. In the silent morning

when we least expect it, it is there
  on the gleaming white porcelain: the silver scales,
    the many feelers busy, busy, so fast, it is

unnerving, causing a certain panic in us,
  a galvanic revulsion (Will it reach us
    before we reach it?
), its body

translucent, indefinable, an electric jelly
  moving with beautiful sweeps of the feet
    like a sinuous trireme, delicate and indecent,

sexual and cleopatric. It moves for a moment
  in the light, while its silver flashes and slides,
    and part of us notices an elusive beauty,

an ingenious grace in what has been cast off.
  As if tears and the invisibly falling dandruff,
    skin cells and eyelashes

returned with an alien and silken intelligence,
  as if chaos were always disintegrating into order,
    elastic and surprising,

as if every cell had a second chance
  to link and glitter and climb toward the light,
    feeling everything as if for the first time —

pausing stunned, stupefied with light.
  Before we, frightened by such possibilities,
    with a large wad of tissue come down on it,

and crush it until it is nothing
  but dampness and legs, an oily smear
    writing a broken Sanskrit on the paper,

a message we choose not to read
  before committing it to the water
    swirling blankly at our touch,

hoping that will take care of it,
  trying not to think of it — the dark
    from which it will rise again.

 

-Julie

http://www.unrealnature.com/

June 29, 2009

Atget

Filed under: Uncategorized — unrealnature @ 8:20 am

It is worth trying to imagine what kind of life he led, this Paris pedestrian, laden with cumbersome equipment that made his work as arduous as that of a street-porter. Imagine what it meant to have to lug a bellows camera, with glass plates in plate-holder, a focusing cloth, a lens case, a wooden tripod: twenty kilograms at the very least, well over forty pounds. Flexible negatives had come onto the market before the turn of the century; far lighter than glass, they made exterior shots much easier, but Atget never used them, remaining faithful to his old equipment and his old habits. He went everywhere by bus and Metro; a notebook of his, now in The Museum of Modern Art in New York, gives clients’ names and addresses marked with the name of the nearest subway station. Atget‘s technique is known to us. Virtually all his photographs are albumen prints. The paper was sold impregnated with whipped and salted egg white, and the photographer soaked it in a bath of silver nitrate. Sensitized and dried, the paper was laid in the printing frame with the glass negative and exposed to sunlight until an image appeared, then fixed and toned with a salt of gold. The resulting images were very “clean,” quite unlike the blur favored by the pictorialist photographers of the period. The prints were fairly stable in themselves, but the thinness of the paper and its tendency to curl induced Atget (along with many other photographers) to paste his photographs onto card: a disastrous practice, since the acid in the card discolored the prints, and the albumen, prevented from curling, developed a network of cracks. Subsequently, Atget used aristotypes, on citrate paper, which was sold ready-sensitized and was — in theory, at least — more stable. Unfortunately, however, these were poorly fixed and washed, and a number of images have been irreparably stained.

Atget used an 18 x 24 cm plate camera, with a short-focus lens, mostly with a rising front. [ … ] He positioned his camera low, no doubt so that he could sit comfortably on his bag of plate-holders. Atget liked to work in one particular kind of light, that of the early morning. It may be that this originally came about because his institutional clients wanted a documentary record uncluttered by people. He operated in a world without vehicles or pedestrians, and this imparts a strange quality to his photographs, especially when seen in any quantity. There is a weirdness in his empty streets, his impenetrable facades, his gaping dormers, his windows opening onto shadowy, inscrutable interiors; and it is easy to understand why they fascinated De Chirico, another resident of the Rue Campagne-Première, whose dummy-like figures owe a lot to Atget.

All of today’s quotes are from the book, Atget Paris, by Laure Beaumont-Maillet (1992).

atget_by_Abbott
Portrait of Atget by Berenice Abbott, 1927

… Why did the Surrealists adopt Atget? Man Ray always claimed that he had discovered him; and Robert Desnos confirms this. However, try though they might to take him over, Atget entreated them to do nothing of the sort. When Man Ray offered to publish some of his works (notably the Corsets of 1912) in the June 1926 number of La Révolution surréaliste, Atget gave this surprising response: “Do not mention my name. The pictures I take are simply documents.”

[ … ]

Atget worked without a break, day in, day out, patiently recording the face of a Paris that was constantly changing. He was not interested in Haussmann’s Paris — rich, grand, pretentious — but in a picturesque section of wall that was on the point of collapsing, or in any touching or unexpected detail. “Having seen the famous sights of a great city,” wrote Pierre Mac Orlan, “does not necessarily entitle one to hear its private song.” In Paris, perhaps it is Atget, more than anyone else, who allows us to hear that private song. The images that he gives us are precise and profoundly honest. Mute witnesses, his photographs look out at us with something like a reproach; for a topographical view in a photograph has a completely different flavor from the same view in a painting or a drawing: it has the bitterness that springs from direct proximity, and the emotion that is stirred by photography’s unequaled ability to resurrect. In a sense, Atget’s work has escaped from its creator; it is and will continue to be subject to an interpretative process that would have astonished him more than anybody. On every side, efforts are made to appropriate him, or at least to fashion his work into the expression of an ideology. Every commentator looks for the man behind the myth; but the man remains elusive, and we must reconcile ourselves to that. Even the self-evident can retain its mystery.

His technique belonged to the nineteenth century; his vision firmly belongs to the twentieth. His gaze was direct and frank; but he, more than anybody, was able to make the imaginary coexist with the real. And so he invented modern photography.

That last sentence is a bit of a stretch, though he was, indeed, influential.

For an interesting look at Atget’s work, side by side with photographs of the same locations taken by Christopher Rauschenberg, see Rephotographing Atget: photos and text by Christopher Rauschenberg. [Navigation buttons are at the bottom of the page; Atget’s images are on the left, Rauschenberg’s on the right.]

On this page, you can see a number of pictures of the inside of Atget’s ‘atelier.’ [ link ]

-Julie

http://www.unrealnature.com/

Propaganda, Prepropaganda, and the Merely Aesthetic

Filed under: Uncategorized — unrealnature @ 8:09 am

Photographs in and of themselves may prove to be like Scripture, which the Devil has been known to quote to his own advantage.

That and all that follows are from the essay, Landscape as Politics and Propaganda, in the collection of essays, Landscape as Photograph, by Estelle Jussim and Elizabeth Lindquist-Cock (1985):

In a recent issue of Life magazine, and article on the increasing destruction of Montana’s Glacier National Park featured a large color photograph of a meadow, a river, and a distant gloriously snow-covered peak. The meadow was strewn with abandoned automobile carcasses, rusting vehicles in considerable numbers and of no explained origin. The otherwise impassioned text commented on this eyesore as being a “merely aesthetic” problem. The more conspicuous dangers were the strip-mining operations and energy resource explorations on the boundaries of the park, the atomic dump sites nearby, and the unwitting destruction of the delicate balance of nature by admiring hordes of tramping tourists. In other national parks and preserves similar destruction continues unabated. As the Life reporter noted, for more than a hundred days a year, smog drifting in from Los Angeles prevents tourists from seeing across to the opposite rim of the Grand Canyon. … The list of elements and activities destructive of nature — not to mention human health — is unbearably long. Yet it is typical that the commentary about the trashing of our wilderness areas by the automobile culture is relegated to the “merely aesthetic.” We suggest that this scanting of the aesthetic issue represents a much deeper aspect of American behavior toward nature and the fundamental ideologies which inform that behavior.

We might begin by blaming Abraham Maslow for listing the aesthetic need last in his famous hierarchy of human needs. Not only does he place it last, but he insists that only for some people is the desire for the beautiful a genuine need. Not everybody has this need. Maslow does not say who does, but the implication is that they are probably aristocrats or the “artistic” minority.

[ … ]

For inner-city minorities, trapped by poverty, the segregation of spectacular scenery into national parks beloved by landscape photographers is a gesture unrelated to their desperation. To live in the South Bronx or in Harlem is to experience “nature” in the form of an occasional sumac tree — what New Yorkers called “railroad trees” because they grew along the tracks into the city — and mammoth legions of roaches, rats, pigeons, sparrows, and the tough grass which even cement pavements cannot entirely squelch.

How does seeing a stunning color photograph by, say, Eliot Porter, assist these slum dwellers in their daily lives? For some, if they can afford the Sierra Club calendars, pictures of golden aspens and snowy pines may refresh spirit, reminding them of the nature of which we are all a part. On the other hand, for others, such pictures only widen the gulf between their status as social outcasts and economic pariahs and that of the very rich, who can afford to travel to spas, national parks, and their own more private nature enclaves whenever they like. The national parks were conceived in the spirit of democratic sharing, rich and poor alike — that was a significant part of the ideology and political pragmatics of nineteenth-century congressional actions. And although photographs can distribute images of these wonderful places, they can never alleviate the bitterness of those who can hardly afford the busfare to Bear Mountain.

[ … ]

During the Great Depression of the 1930s, when Nazi Germany was perfecting its own style of propaganda and Hitler was preaching conquest, genocide, and totalitarianism, there was violent dissent among photographers as to what their ethical and artistic stance should be. The situation can be summed up by a statement attributed to Henri Cartier-Bresson; indeed, it is much more than a statement, it is a shocked expostulation: “The world is going to pieces and people like Adams and Weston are photographing rocks!” Because he believed that humanity needs the purely aesthetic as much as anything material, Adams defended himself: “I still believe there is a real social significance in a rock — a more important significance therein than in a line of unemployed.” Unfortunately, Adams did not explain what that social significance might be, and he was accused of being politically and humanly insensitive.

The story is reminiscent of an exchange that took place between Berthold Brecht and André Gide. The latter, writing at the time of the appalling expansion of nazism, happened to speak about a tree he greatly admired. Brecht wrote, sorrowfully,

What kind of times are they, when
A talk about trees is almost a crime
Because it implies silence about so many horrors?

To talk about trees, to photograph trees, to think about nature, were all insupportable in the midst of barbarism.

… Like poetry, photography, with its compression and metaphor, can be considered a seductive anodyne, not a remedy; it could even be condemned as a hypnotic substitute for direct experience leading to action for socially beneficial causes.

When Roy Stryker was exhorting his Farm Security Administration photographers during the Second World War, he fully recognized that what was needed was a gigantic propaganda effort. For landscape, the Great Depression and its Dust Bowl documents were to be forgotten. “Emphasize the idea of abundance — the ‘horn of plenty’ — and pour maple syrup over it … I know your damned photographer’s soul writhes, but … Do you think I give a damn about a photographer’s soul with Hitler at our doorstep?” Thus, instead of Dorothea Lange’s tractored-out farm, Americans were treated to images of this land as a vast granary, with wheat and corn sheaves stacked in never-ending rows.

This last is from the beginning of the essay; it precedes all of the above quotes:

Modern propagandists — by whatever name and of whatever political persuasion — recognize that propaganda for a cause can succeed only if a number of conditions are present in the decision-making context. To begin with, there is more than one kind of propaganda: Jacques Ellul calls these prepropaganda and active propaganda, the former obviously being indispensable to the latter. Prepropaganda has the task of mobilizing our psychological responses, loosening the old reflexes, and instilling images and words in repetitive formulas. According to Ellul, prepropaganda, perhaps surprisingly, “does not have a precise ideological objective; it has nothing to do with an opinion, an idea, a doctrine. It proceeds by psychological manipulations, by character modifications, by the creation of feelings or stereotypes useful when the time comes.”

… Playing on the already present assumptions and unconscious motivations of individuals and groups is the art of the propagandist. In order to be successful as propaganda, photography has to create images that not only resonate with what people will accept, but also has to contribute to the creation of the fundamental myths by which we all live. If you are on the side of the angels, this might be the “myth” (or ideology) of democracy, liberty, productivity, authority, the dignity of labor, or the sanctity of life. But there are other myths, like racial superiority, religious “truth,” the beliefs that life is dog-eat-dog in the best tradition of social Darwinism or that people are no good and that women deserve to be raped, for those who feel too threatened to be civilized.

It would not be hard to make an argument that all photographs are, to some degree, prepropaganda. Those that are “merely aesthetic” are those that have a greater — not lesser — degree of potency.

-Julie

http://www.unrealnature.com/

June 28, 2009

in the whole of the atmosphere

Filed under: Uncategorized — unrealnature @ 7:57 am

The air is filled with endless images of the objects distributed in it; and all are represented in all, and all in one, and all in each, whence it happens that if two mirrors are placed in such a manner as to face each other exactly, the first will be reflected in the second and the second in the first. The first being reflected in the second takes to it the image of itself with all the images represented in it, among which is the image of the second mirror, and so, image within image, they go on to infinity in such a manner as that each mirror has within it a mirror, each smaller than the last and one inside the other. Thus, by this example, it is clearly proved that every object sends its image to every spot whence the object itself can be seen; and the converse: That the same object may receive in itself all the images of the objects that are in front of it. Hence the eye transmits through the atmosphere its own image to all the objects that are in front of it and receives them into itself, that is to say on its surface, whence they are taken in by the common sense, which considers them and if they are pleasing commits them to the memory. Whence I am of opinion: That the invisible images in the eyes are produced towards the objects, as the image of the object to the eye. That the images of the objects must be disseminated through the air. An instance may be seen in several mirrors placed in a circle, which will reflect each other endlessly.

When one has reached the other it is returned to the object that produced it, and thence — being diminished — it is returned again to the object and then comes back once more, and this happens endlessly. If you put a light between two flat mirrors with a distance of 1 braccio between them you will see in each of them an infinite number of lights, one smaller than another, to the last. If at night you put a light between the walls of a room, all the parts of that wall will be tinted with the image of that light. And they will receive the light and the light will fall on them, mutually, that is to say, when there is no obstacle to interrupt the transmission of the images. This same example is seen in a greater degree in the distribution of the solar rays which all together, and each by itself, convey to the object the image of the body which causes it. That each body by itself alone fills with its images the atmosphere around it, and that the same air is able, at the same time, to receive the images of the endless other objects which are in it, this is clearly proved by these examples. And every object is everywhere visible in the whole of the atmosphere, and the whole in every smallest part of it; and all the objects in the whole, and all in each smallest part; each in all and all in every part.

That’s from The Notebooks of Leonardo da Vinci —  Complete, Volume I— Leonardo da Vinci (1452 – 1519); translated by Jean Paul Richter 1888.

Yes, Leonardo wanted to add to our discussion of the Droste effect (and more). And you will surely have noticed that said Droste effect is a form of image sequence (and more and more) albeit a rather abundant one (infinity).

-Julie

http://www.unrealnature.com/

searching me out

Filed under: Uncategorized — unrealnature @ 7:48 am

All of the following is from the autobiographical book, All the Strange Hours: The Excavation of a Life, by Loren Eiseley (1975):

… The thud of my head hitting the floor had sounded so remote I never had time to relate it to myself. I simply ceased to be. There was a body lying in the dusk on the stairs, but whatever motivated that body, consciously dwelt upon its problems, looked after its need, had vanished. Yet somewhere in that silence where I no longer existed, the heart had picked up and labored in the midst of a retching sickness. Swimming and clambering phagocytes had swept through an arterial system that had become a battleground, a Gettysburg of charging forces. John Hunter, the surgeon, once spoke of a principle of incompleteness. I suspect he was groping toward whatever it may be, tangible or intangible, that sews up our ragged heads and limbs if the stuffing has not all run out of them.

The experts say that within six minutes of heart failure a man’s brain, which consumes enormous quantities of oxygen, will be injured beyond recall. That with prompt medical attendance and mouth-to-mouth resuscitation one may be brought back uncertainly, perhaps, over a thirty-minute threshold. What is shrouded in mystery, however, is the way by which the sprawled body, even if the heart has not ceased to beat, reassembles itself as an entity and relights the flickering candle of consciousness.

I was gone so far into the dark that no dream whispered to me, no sound again troubled my ear. Consciously, I did not exist. But something was still alert in me, the Synthesizer. A hurrying, jostling cavalcade of hemocytes was rushing oxygen toward those cranial abysses into which I had vanished. Something, some toiling cellular entity of which I was unaware, was searching me out, reconstructing me, setting failing ganglions to sputtering, reactivating all manner of wildly spinning compasses. Today as I read of the achievements of physics, of those leaping, impinging, flying phantoms out of which is created the nature that we know, I cannot but think of ourselves as some microcosmic parallel.

Our blood contains ingredients as mysterious and as abounding as the micro-particles below the atom. Our spider web of neurons holds in its tenuous interwoven film our memories and our conscious existence. Yet where do those memories abide when the dark comes down? Who seeks to restore the snuffed-out candle? Why should there be this enormous effort to reactivate a sleeping manikin? From whence comes the organizer, sending millions of cells to do battle in the dark and from the body of this death to hand up one solitary Lazarus?

Oh, I know the Synthesizer has his limits, but still he sent my father back just one more time a long and weary distance to my brother. In all my remaining years I have been grateful to those unseen toilers who, when my will had failed, had recreated what individually they neither knew nor cared about.

-Julie

http://www.unrealnature.com/

June 27, 2009

The Living and the Dead

Filed under: Uncategorized — unrealnature @ 7:55 am

In the Preface of the book, Life’s Devices: The Physical World of Animals and Plants, by Steven Vogel (1988), one finds this:

The bits of physics that play a part here are well-plumbed, well-understood, and not the least bit controversial. They are, furthermore (as a bumper sticker once proclaimed), what makes the world go around. Oddly and unfortunately, they’re not dear to the hearts of all of us — for some they’re items of positive antipathy. Perhaps some social scientist might study the division of society into those superior sorts for whom matters mechanical are rational and those others for whom they’re lurking demons or revealed truth. Education seems to make little difference. By this criterion the auto mechanic has culture while most lawyers remain primitive. The division extends to scientists, with biologists as divided as any, except that most of us were subjected to a few college courses in physics and mathematics, so we can’t easily admit either innocence or fear. As James Thurber said about the founding editor of The New Yorker, “Ross approached all things mechanical, to reach for a simile, like Henry James approaching Brigitte Bardot. There was awe in it, and embarrassment, and helplessness.”

“Superior sorts”? In their own minds, perhaps. Why are so many scientists so vain about their conceptions of truth; so unaware of how much they don’t know and will never know?

The next bit is from an article, What Skepticism Reveals about Science, by Michael Shermer in the July 2009 issue of Scientific American. Unfortunately, Shermer is not skeptical enough:

… What I want to believe based on emotions and what I should believe based on evidence does not always coincide. And after 99 monthly columns of exploring such topics (this is Opus 100), I conclude that I’m a skeptic not because I do not want to believe but because I want to know. I believe that the truth is out there. But how can we tell the difference between what we would like to be true and what is actually true? The answer is science.

No it’s not. If he had said “how can we tell the difference between what we would like to be true and what is actually not true?” then I would agree with him. I love science; I believe in the scientific method but I very much doubt that it has ever or will ever find “the” truth. What it does do, and does very well, is let us sort out what is not true from what might be true.

Later in Shermer’s piece, he says this:

To be fair, not all claims are subject to laboratory experiments and statistical tests. Many historical and inferential sciences require nuanced analyses of data and a convergence of evidence from multiple lines of inquiry that point to an unmistakable conclusion. Just as detectives employ the convergence of evidence technique to deduce who most likely committed a crime, scientists employ the method to determine the likeliest explanation for a particular phenomenon. Cosmologists reconstruct the history of the universe by integrating data from cosmology, astronomy, astrophysics, spectroscopy, general relativity and quantum mechanics. Geologists reconstruct the history of Earth through a convergence of evidence from geology, geophysics and geochemistry. Archaeologists piece together the history of a civilization from pollen grains, kitchen middens, potshards, tools, works of art, written sources and other site-specific artifacts. Climate scientists prove anthropogenic global warming from the environmental sciences, planetary geology, geophysics, glaciology, meteorology, chemistry, biology, ecology, among other disciplines. Evolutionary biologists uncover the history of life on Earth from geology, paleontology, botany, zoology, biogeography, comparative anatomy and physiology, genetics, and so on.

Once an inferential or historical science is well established through the accumulation of positive evidence, however, it is just as sound as a laboratory or experimental science.

The vast majority of claims are not subject to laboratory experiments and statistical tests. Words like “nuanced analysis”, “integrating the data”, “reconstruct the history” “piece together the history” — do not lead to the “actually true.” They can or may lead to the more true — or to the less false.

Returning to Vogel’s book, from which I quoted at the start of this post, in Chapter 1: Constraints and Opportunities, he says the following, without blushing:

Biologists love their organisms, collectively, singly, sliced, macerated, or homogenized. As D’Arcy Thompson (1942) put it, biologists are “deeply reluctant to compare the living with the dead, or to explain by geometry or by mechanics the things which have their part in the mystery of life.” But we will repeatedly use the “dead” to explain the “living.” Explanation requires simplification, and nothing is so un-simple as an organism. And the most immediate sort of simplification is the use of nonliving models, whether physical or (even) mathematical.

Science is, in fact, utterly addicted to models for simplification and generalization. Even a tiny aspect of the world is just too complex to yield to simultaneous and systematic analysis of all of its diverse characteristics. Consider, for a moment, your left thumb — how many facets of this minor appendage might be measured, recorded, and subjected to statistical treatment? Simplification and abstraction have marked all progress in science; one begins very simply and then adds elements of complication as necessary and possible.

Don’t you love how he breezily says, “then adds elements of complication as necessary and possible” ? Whee …!

A good scientist would be as full of awe and helplessness as was New Yorker Editor, Ross in the quote at the start of this post.

(Vogel’s book is actually really good if you’re interested in the mechanics of living things.)

[I hear Mr. Girvan snorting. Ray, go study  your left thumb.]

-Julie

http://www.unrealnature.com/

June 26, 2009

Later

Filed under: Uncategorized — unrealnature @ 6:46 am

… the recalibration of subjective timing is not a party trick of the brain; it is critical to solving the problem of causality. At bottom, causality requires a temporal order judgment: did my motor act come before or after that sensory signal? The only way this problem can be accurately solved in a multisensory brain is by keeping the expected time of signals well calibrated, so that “before” and “after” can be accurately determined even in the face of different sensory pathways of different speeds.

It must be emphasized that everything I’ve been discussing is in regard to conscious awareness. It seems clear from preconscious reactions that the motor system does not wait for all the information to arrive before making its decisions but instead acts as quickly as possible, before the participation of awareness, by way of fast subcortical routes. This raises a question: what is the use of perception, especially since it lags behind reality, is retrospectively attributed, and is generally outstripped by automatic (unconscious) systems? The most likely answer is that perceptions are representations of information that cognitive systems can work with later. Thus it is important for the brain to take sufficient time to settle on its best interpretation of what just happened rather than stick with its initial, rapid interpretation. Its carefully refined picture of what just happened is all it will have to work with later, so it had better invest the time.

That’s from the end of a long essay, Brain Time, by David M. Eagleman (Jun 24, 2009) on The Edge. Here is more:

… It has long been recognized that the nervous system faces the challenge of feature-binding — that is, keeping an object’s features perceptually united, so that, say, the redness and the squareness do not bleed off a moving red square. That feature-binding is usually performed correctly would not come as a surprise were it not for our modern picture of the mammalian brain, in which different kinds of information are processed in different neural streams. Binding requires coordination — not only among different senses (vision, hearing, touch, and so on) but also among different features within a sensory modality (within vision, for example: color, motion, edges, angles, and so on).

But there is a deeper challenge the brain must tackle, without which feature-binding would rarely be possible. This is the problem of temporal binding: the assignment of the correct timing of events in the world. The challenge is that different stimulus features move through different processing streams and are processed at different speeds. The brain must account for speed disparities between and within its various sensory channels if it is to determine the timing relationships of features in the world.

What is mysterious about the wide temporal spread of neural signals is the fact that humans have quite good resolution when making temporal judgments. Two visual stimuli can be accurately deemed simultaneous down to five milliseconds, and their order can be assessed down to twenty-millisecond resolutions. How is the resolution so precise, given that the signals are so smeared out in space and time?

To answer this question, we have to look at the tasks and resources of the visual system. As one of its tasks, the visual system — couched in blackness, at the back of the skull — has to get the timing of outside events correct. But it has to deal with the peculiarities of the equipment that supplies it: the eyes and parts of the thalamus. These structures feeding into the visual cortex have their own evolutionary histories and idiosyncratic circuitry. As a consequence, signals become spread out in time from the first stages of the visual system (for example, based on how bright or dim the object is).

So if the visual brain wants to get events correct timewise, it may have only one choice: wait for the slowest information to arrive. To accomplish this, it must wait about a tenth of a second. In the early days of television broadcasting, engineers worried about the problem of keeping audio and video signals synchronized. Then they accidentally discovered that they had around a hundred milliseconds of slop: As long as the signals arrived within this window, viewers’ brains would automatically resynchronize the signals; outside that tenth- of- a- second window, it suddenly looked like a badly dubbed movie.

This brief waiting period allows the visual system to discount the various delays imposed by the early stages; however, it has the disadvantage of pushing perception into the past. There is a distinct survival advantage to operating as close to the present as possible; an animal does not want to live too far in the past. Therefore, the tenth-of- a-second window may be the smallest delay that allows higher areas of the brain to account for the delays created in the first stages of the system while still operating near the border of the present. This window of delay means that awareness is postdictive, incorporating data from a window of time after an event and delivering a retrospective interpretation of what happened. Among other things, this strategy of waiting for the slowest information has the great advantage of allowing object recognition to be independent of lighting conditions. Imagine a striped tiger coming toward you under the forest canopy, passing through successive patches of sunlight. Imagine how difficult recognition would be if the bright and dim parts of the tiger caused incoming signals to be perceived at different times. You would perceive the tiger breaking into different space-time fragments just before you became aware that you were the tiger’s lunch. Somehow the visual system has evolved to reconcile different speeds of incoming information; after all, it is advantageous to recognize tigers regardless of the lighting.

Read the full piece. [ link] You won’t want to miss the description of their experiment to determine if time really does slow down when you’re scared shitless:

… we harnessed participants to a platform that was then winched fifteen stories above the ground. The perceptual chronometer, strapped to the participant’s forearm like a wristwatch, displayed random numbers and their negative images alternating just a bit faster than the participant’s determined threshold. Participants were released and experienced free fall for three seconds before landing (safely!) in a net. During the fall, they attempted to read the digits.

-Julie

http://www.unrealnature.com/

Liquid Cooled

Filed under: Uncategorized — unrealnature @ 6:39 am

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Those last two (above) show what they do when they scent something they don’t want to mess with (bear or coyote). Tense and silent.

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Until next time …

-Julie

http://www.unrealnature.com/

June 25, 2009

Felix Culpa

Filed under: Uncategorized — unrealnature @ 7:54 am

Ezra Pound wrote: “I lost my center fighting the world … I tried to make a paradiso terrestre.” What is the connection between these two failures? And what would we do with that earthly paradise had Pound been able to “make” one after all? The critic Lionel Trilling wrote back in 1964 that there is nothing that we moderns recoil from as much as the idea of Eden:

How far from our imagination is the idea of “peace” as the crown of spiritual struggle! The idea of “bliss” is even further removed. The two words propose to us a state of virtual passivity which is the negation of the “more life” that we crave …  We dread Eden, and of all Christian concepts there is none which we understand so well as the felix culpa and the “fortunate fall”; not, of course, for the reason on which these Christian paradoxes were based, but because by means of the sin and the fall we managed to get ourselves expelled from that dreadful place.

That’s from the last chapter of the book, Gardens: An Essay on the Human Condition, by Robert Pogue Harrison (2008). Heres is a little bit from the Preface of the book to give a hint of his position:

… human gardens, however self-enclosed their world may be, invariably take their stand in history, if only as a counterforce to history’s deleterious drives. When Voltaire ends Candide with the famous declaration “Il faut cultiver notre jardin,” the garden in question must be viewed against the background of the wars, pestilence, and natural disasters evoked by the novel. The emphasis on cultivation is essential. It is because we are thrown into history that we must cultivate our garden. In an immortal Eden there is no need to cultivate, since all is pregiven there spontaneously. Our human gardens may appear to us like little openings onto paradise in the midst of the fallen world, yet the fact that we must create, maintain, and care for them is the mark of their postlapsarian provenance. History without gardens would be a wasteland. A garden severed from history would be superfluous.

And, of course, a garden can be a metaphor for all kinds of created things.

-Julie

http://www.unrealnature.com/

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