Week 2Visual Perception

ART 100Understanding Visual Culture

agenda 9.2.14

questions?

artworlds: brief review

function of the eye

how eye and brain work together to create vision

the active, constructed nature of vision

What is “art-like” about the Mona Lisa?

it is an oil painting,

it is painted by one of the most famous artists in history,

and it is located in the Louvre, one of the most well-known art museums in the world.

LEONARDO DA VINCI Portrait of Lisa Gherardini, wife of Francesco del Giocondo, known as the Mona Lisa (the Joconde in French)c. 1503–06oil on panel30.3 x 20.8 inchesAcquired by François I in 1518

“Leonardo undertook to execute, for Francesco del Giocondo, the portrait of Mona Lisa, his wife, and after he had lingered over it for four years, he left it unfinished; and the work is today in the possession of King Francis of France, at Fontainebleau. Anyone wishing to see the degree to which art could imitate nature could readily perceive this from the head; since therein are counterfeited all those minutenesses that with subtlety are able to be painted: seeing that the eyes had that lustre and moistness which are always seen in the living creature, and around them were the lashes and all those rosy and pearly tints that demand the greatest delicacy of execution. The eyebrows, through his having shown the manner in which the hairs spring from the flesh, here more close and here more scanty, and curve according to the pores of the flesh, could not be more natural. The nose, with its beautiful nostrils, rosy and tender, appeared to be alive. The mouth with its opening , and with its ends united by the red of the lips to the flesh-tints of the face, seemed, in truth, to be not colours but flesh. In the pit of the throat, if one gazed upon it intently, could be seen the beating of the pulse: and indeed it may be said that it was painted in such a manner as to make every brave artificer, be he who he may, tremble and lose courage. He employed also this device: Mona Lisa being very beautiful, while he was painting her portrait, he retained those who played or sang, and continually jested, who would make her to remain merry, in order to take away that melancholy which painters are often wont to give to their portraits. And in this work of Leonardo there was a smile so pleasing , that it was a thing more divine than human to behold, and it was held to be something marvelous, in that it was not other than alive.”

Giorgio Vasari ‘The Lives of the Most Excellent Painters, Sculptors, and Architects’ 1550

http://www.nytimes.com/interactive/2012/04/14/world/

europe/Not-Just-Another-Fake-Mona-Lisa.html?ref

=europe&_r=0

Marcel DUCHAMPL.H.O.O.Q1919postcard with doodle

Andy WARHOL, Double Mona Lisa, 1963Silkscreen ink on linen28-1/8 x 37-1/8 inches

Andy WARHOL Mona Lisa1963Acrylic and silkscreen on canvas44 x 29 inches

Andy WARHOLThirty Are Better Than One 1963Synthetic polymer paint and silkscreen ink on canvas110 x 94 inches

Vik MUNIZ, Double Mona Lisa, After Warhol, (Peanut Butter + Jelly) 1999,cibachrome

Briefly, we will

study the eye and the dynamic process of visual perception, to understand how our brains create the images we see.

But in general in this course, we are interested not in the “nature” of vision, but in its culture; in other words, how humans have developed languages of visual communication given our status as sighted creatures.

http://www.aoa.org/patients-and-public/resources-for-teachers/how-your-eyes-work?sso=y

schematic diagram of how vision works(please note: this diagram is WRONG)

Most people assume that vision works as pictured in the diagram below.Put in words: our vision is just what our eye sees and reports to the brain.

“the eye is like a camera”

This analogy holds up to a point.

The point at which it no longer holdsis the retina.

Please note: this diagram is TRUE up to a point and then becomes FALSE.

Please note: this diagram is still a bit misleading, but it’s a whole lot better than the previous one.

why is the eye/camera idea wrong?

FIRST REASON. There is no “image,” no picture in the eye at all. All that happens in the eye is that light admitted through the pupil and focused through the lens differentially stimulates the neuron-rich tissue at the back of the eye (the retina), sending patterns of electrical impulses to the brain (specifically to a region of the brain known as the visual cortex), where the signals must be processed and interpreted to create what we see.

there is animal and human evidence for 3 discrete processing systems

“Although the visual processing mechanisms are not yet completely understood, recent findings from anatomical and physiological studies in monkeys suggest that visual signals are fed into at least three separate processing systems. One system appears to process information mainly about shape; a second, mainly about color; and a third, movement, location, and spatial organization.”

Human psychological studies support the findings obtained through animal research. These studies show that the perception of movement, depth, perspective, the relative size of objects, the relative movement of objects, shading, and gradations in texture all depend primarily on contrasts in light intensity rather than on color.”SOURCE:

http://www.brainfacts.org/sensing-thinking-behaving/senses-and-perception/articles/2012/vision-processing-information/

in the third system (depth/location/movement)

“About 60 years ago, scientists discovered that each vision cell’s receptive field is activated when light hits a tiny region in the center of the field and inhibited when light hits the area surrounding the center. If light covers the entire receptive field, the cell responds weakly.”

Another way to put this is: “the visual process begins by comparing the amount of light striking any small region of the retina with the amount of surrounding light.”

This process is enhanced by “lateral inhibition,” in which all but the strongest signals are filtered out by the retina before even reaching the brain. (Preference for edges.)

SOURCE: http://www.brainfacts.org/sensing-thinking-behaving/senses-and-perception/articles/2012/vision-processing-information/

Our ability to, judge distance, move through space, avoid obstacles,—these are all INFERENCES drawn from information about contrasts between light intensity rather than actual visual data—even though we perceive them as properties of our vision.

This is ANOTHER REASON why the eye/camera idea is completely misleading.

let’s summarize

The brain constructs your field of vision from electrical impulses sent by the eye.

The eye collects data on shape

color

position/location/movement

and these seem to be processed in the brain by three discrete systems.

The raw data entering the third system has to do with differences in light intensity. These signals are enhanced by the retina through the process of lateral inhibition and are subsequently interpreted by the visual cortex to produce our field of vision, which we experience as continuous and compelling rather than as a series of approximations of distance, size and depth via contrasts between light and shadow.

J.S. COPLEYMrs. Ezekiel Goldthwaitoil on canvas50 1/8 x 40 1/8 inches

This human perceptual preference for “edges”—areas of high contrast betweenlight and shadow—is also exploited by artists wanting to create convincing three-dimensional illusions in their two-dimensional art.

“blind spot” experiment

http://serendip.brynmawr.edu/bb/blindspot1.html

http://serendip.brynmawr.edu/bb/blindspot/

http://serendip.brynmawr.edu/bb/latinhib.html

http://dragon.uml.edu/psych/illusion.html

In this class we consider…

not the spectrum of light visible to the human eye,

but our culturally bound sense of what colors mean.

But in what human beings have made

of vision.

In other words, not what vision is,

M.C. Escher (Dutch, 1898 – 1972), Drawing Hands, 1948, ithograph, 11 1/8 x 13 1/8 in