a byzantine machine

For most, the calculus of mind has its cold, invariable limits. Attention and repetition allow us the province of only a small set of our experiences, and most of the world's features are simply forgotten. Are these details never present? Are they instead discarded by the subconscious mind?

Some savants have a startling ability to recall experiences and facts, both vital and inane. Often these abilities are associated with a traumatic brain injury or developmental disabilities. In addition to eidetic memories, some individuals also possess prodigious cognitive abilities. Daniel Tammet is one such prodigious savant. Since the age of four, his mind has seen the world as a landscape of numbers. In grade school, Daniel would spend his recess counting the hopscotch scores of the other children. He would gaze endlessly, pondering the patterns in nature and in the lives of his peers. As a synesthesiac, each number looked and felt unique to him. Some were movements, others towering forms, and still others deep and complex feelings.

With each number a separate sensual experience, it's no wonder that Daniel can easily remember them. His recitation of pi to more than 22,000 digits astounded even those familiar with his condition. Even more remarkable are his skills of mental computation. Daniel can operate on numbers to the hundredth digit in his head. He can determine the primality of a number by feeling. He claims that the answers simply appear, without the use of a deliberate algorithm.

Daniel, like some other savants, also has an eidetic memory. In a stunt performed for a British television show, he learned to speak Icelandic, considered to be a difficult and nuanced language, in only a week. To one like Daniel, we must seem blind, deaf, absent-minded.

The present might seem almost intolerable in its richness and sharpness, as Jorge Luis Borges describes it in Funes the Memorious. Like Daniel Tammet, Ireneo Funes is cursed and blessed with supernal memory. His recollections are every bit as sensual as the lives of others, his days vertiginous. Borges writes of Funes: "He could continuously discern the tranquil advance of corruption, of decay, of fatigue ... He was the solitary and lucid spectator of a multi-form, instantaneous and almost intolerably precise world." I cannot imagine the stammering grandeur that reality would hold all at once. We can only marvel at these savants, these insomniacs among us.

sight unseen

It may be essential to our survival that we are hardwired to recognize and respect the human face. Even very soon after birth, a baby's inchoate brain can focus on and seemingly discriminate between faces. Interpersonal relationships, communication and trade, of course, have been indispensable to mankind for eons. It's no surprise, then, that nature would hard-code this instinct into our incipience.

Some more surprising perceptual adaptations occur after birth, and many are largely manifestations of cultural experience. Visual perception, in particular, can be tempered by context and by the perceiver's world-view. Recently, research has been conducted at MIT differentiating between particular perceptive tendencies of Asians versus Americans of European descent. The cultures in question are of course widely different - philosophically and aesthetically, and these differences apparently manifest themselves in subjects' visual perception.

The archetypal Asian world-view revolves around a concept of harmony. Major philosophical movements: Taoism, Buddhism, and Confucianism, all identified with this precept. Asian architecture, largely, is composed horizontally and resonates with the landscape. The ornate roof style of traditional architecture is a gesture to resolve the roof-line of a building in organic forms. This tendency fits into the Asian world-view, in which individual objects are typically seen as parts of larger, organic wholes. When shown a photograph, Asian subjects tended to concentrate disproportionately on the background and larger context of a scene. Americans tended to favor the foreground or most pronounced object.

Western culture and philosophy, too, tend to put more emphasis on the individual. Americans, in this sense, are less aware of context and relativity. This is the American ego - our great, enterprising strength. But it also may have hindered our ability to understand the world around us. Richard Nesbitt, one of the study's investigators, cites the inability of Western scientific minds to quickly grasp the nature of physical forces:

"Aristotle, for example, focused on objects. A rock sank in water because it had the property of gravity, wood floated because it had the property of floating. He would not have mentioned the water. The Chinese, though, considered all actions related to the medium in which they occurred, so they understood tides and magnetism long before the West did."

It may have taken thousands of years for our cultural tendencies to develop, but their effects are ubiquitous. Eye movements and recollections of the participants also tended in the same ways. Kyle Cave of UMass Amherst called this effect "striking", commenting that this kind of effect on low-level perceptual processes suggests another startling, perceptual relation to our cultural origins.

This is doubtless one of many significant effects tempered by culture. Even so, it's implications are astounding.

Visual Perception Tasks
Asian and Western Visual Perception
Eidos
A New Kind of Chop Suey

the eyes have it

One wonders how a structure so complex might have evolved. Vision is an elegant sense, and the human eye has become an extremely specialized organ to its end. One has only to look in the standing water of a pasture to find a possible precursor within the Euglena. These small protists possess an eyespot apparatus; a primitive photo-receptive system which allows the motile Euglena to find a light source strong enough for photosynthesis. The Euglena holds chloroplasts within its transparent body which allow it to undergo this process to manufacture sucrose from water and carbon dioxide. Alga in Euglenaphyceae use a photoreceptor called a paraflagellar swelling near the body's main flagellum. This receptor is interesting in that it is a crystalline structure. The algae uses this dicroic crystalline detector along with a primitive absorbing screen to sense and respond to incident light.

The algal eye of Chlorophyceae contains optics, photo-receptors and elementary components of the signal transduction pathway. Though among the simplest eyes in nature, chlorophycean eyes are capable of detecting light intensity, color, and direction of incidence. Because of their small size, the optical systems on microalgae operate mostly on the basis of reflective surfaces and constructive interference. Although quite disparate macroscopically from the human eye, the chlorophycean eye also uses a rhodopsin chromophore. Retinal is present and used in a slightly different form, but this archaic chromophore is still similar to that used in the human eye. This fundamental system has been nearly conserved from even microalgae.

On early earth-orbital space flights, astronauts were surprised to see this structure staring back at them. It spans nearly thirty miles, and to date no definite scientific explanation has been established for its formation. Because of its scale, the Richat Structure is baffling in its symmetry and basic etiology. It seems that eyes both large and small, given enough time, can pop up in all sorts of places.

Hegemann, Peter. Algal Eyes
Ross, Greg. Futility Closet

f-8 and being there

Trying to capture a scene in any sense is difficult. The ersatz photograph allows us to make a semi-permanent record of appearance, but lacks certain qualities that the eye provides. In my time as a photographer, I've learned to compensate for my equipment. When deciding how to set the camera, I consider the deficiencies of in its sensor, lens and post-processing schema.

The eye is extraordinarily sensitive to light. In certain conditions, the eye can detect the presence of a single photon. Because of the overwhelming amount of visual information being sensed, however, this level of detail is attenuated by the brain. Film and digital sensors attempt to mimic this functionality, but both fall short of the eye's remarkable sensitivity. Because of this disadvantage, professional photographic lenses are usually much larger than the eye, allowing the camera to collect much more of the ambient light. At high sensitivity, which is described in photography by ISO speed, a film emulsion or digital photo-receptor responds to a small duration of light. This increase in sensitivity increases the granularity of a film emulsion and allows random noise to affect the image more significantly in a digital camera. The eye suffers a low-light degradation in image quality, relying on rod cells for contrast and failing to depict a full dynamic range of colour, but the camera's low light ability can be altered by changing its lens. By selecting a lens with a large maximum aperture, I can increase the amount of light entering the camera and thereby increase its noise performance in low light. A very 'fast' lens, that is, one with a large aperture, allows for only a small depth of field. This is a tradeoff for increased dynamic range and a high signal-to-noise ratio.

Where dynamic range is concerned, the eye is vastly superior to the camera, and the digital sensor soundly outperforms film. Although the eye is capable of distinguishing 24 stops of contrast, the brain allows us to adapt to differing dynamic scales and adjust our sensory apparatus to the scene. This is a remarkable ability that cameras can't currently match. My Canon EOS 5D can distinguish only 12 stops. This camera drawback can be mitigated by exposure bracketing - taking pictures of the same scene at different exposures and digitally combining the result. This is called High-dynamic-range (HDR) photography and results in some remarkable images.

Even after taking the photo, a camera works to interpret an image much like the brain. An imaging chip conducts signal processing and control operations to minimize noise and maximize color fidelity. The brain similarly operates to mitigate noise and interpret the output of its photo-receptors. As digital signal processing improves, cameras will be better able to produce faithful images like the eye. The camera's shortcomings are largely due to manufacturing and cost restraints, and I expect to see the interval decrease further in the near future. The eye's machinery has been carefully developed over millions of years, and it represents a true technological marvel.