>the science
deflective video science We designed the "exoptic
fields" video based on aspects of visual optics, neurophysiology, and
visual psychology. Optics and neurophysiology involve the brightness,
colors, orientation, and the motion of visual stimuli capture the
attention of the viewer. Visual perception also involves the active
participation of the perceiver, her active exploration of the environment,
her psychology. This last fact makes addressing visual psychology the key
to successful visual deflection.
The
following are some of the principles of human vision that we employed to
make the "exoptic fields" video viewers' deflect attention from the
screen.
summary: Vision is the primary sensory
function in primates and humans. Our visual perception of the world
depends on complex patterns of stimulation. There are three main areas of
scientific research dedicated to understanding vision:
First, visual optics, the mechanics of how the eye
receives light and the nature of visual stimuli.
Second, visual neurophysiology, or how the brain
interprets visual inputs to construct a unified visual image.
And
finally, visual attention, an area of psychology that describes
both the properties of the image and the expectations and goals of the
observer that determine the attention given to a perceptual
episode.
1- colors choice in "exoptic fields" The eye and its lens catch and
focus light onto the receptor cells of the back of the eye, the retina.
The perception of colors starts at the very center of the retina, in the
fovea. The different frequencies and intensities of light captured at a
particular point of the retina are transformed into neuronal signals by
the photoreceptors. They are of two types, the cones and the rods, but
only the cones mediate diurnal and high acuity color vision. The cones
alone occupy the center of the retina. The cones and rods are made up of
different photopigments. These are red, green or blue, according to the
light frequency they can capture. Their repartition in the retina is
well-described. The red and green cones are localized in the center, with
around the less numerous blue cones organized into a ring (see diagram
I).
These
findings imply that the light frequency that reflects the object observed
will influence the way we need to focus on this object. Thus, the "exoptic
fields" video has adapted its color scheme, blue and yellowish tones, to
target the most peripheral photoreceptors.
2- lines and motions in "exoptic fields" Once the light pattern
strikes the retina, visual signals pass through the axons of the retinal
ganglion cells that form the optic nerve, to neurons that project directly
into the cortical visual areas. At that point the visual inputs are
separated into different components that are analyzed locally in
specialized regions of the cortex. The identification of an object as well
as its spatial position will derive from this analysis (Zeki,
2000).
visual system most sensitive The visual system is most
sensitive to well contrasted colors, sharply defined contours and oriented
edges (Wade, 1991). To lure the eyes away from the center of interest, we
based our approach on opposite characteristics, i.e. smooth contours,
blurred lines, undefined shapes forming an horizontal undulating surface
that move toward the edges of the screen.
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diagram
1) Color regions of the right eye. Color sensitivity can be
determined by means of an instrument called a perimeter, which can
present colored spots of light to peripheral regions of the retina.
All colors can be detected in the central area of the
retina.from "An Introduction: Visual Perception" by Nicholas J.
Wade |
diagram 2) Pathways from the eyes to the visual cortext,
viewed from below. |
continued from left column...
Advertisers have extensively used the fact that fast and sudden
motions of the object(s) of interest converging to the center of the TV
capture the movements of our eyes and our undivided attention (Hillstrom
and Yantis, 1994; Egeth and Yantis, 1997; Corbetta and Shulman, 1998). The
"exoptic fields" video has therefore refined all movement to create very
slowly undulating contours and colors that withdraw to the edges of the
screen.
3- psychology of figurative element, the brick wall, in "exoptic
fields" The overall picture is finally created by combining the
operations of the different specialized regions into a unified visual
image. If how the brain does this is still not understood, the
processes of consciousness and memory are thought to play an essential
role (Hoffman, 2000).
The brick
wall in the "exoptic field" acts to neutralize one’s visual psychology,
ones reflections on: "What will happen next." Meanings commonly associated
with a brick wall will ideally lead quickly to dis-interest on the part of
the observer across many human cultures.
bibliography
Corbetta,
M., and Shulman, G. L.., Human cortical mechanism of visual attention
during orienting and search, Phil. Trans. R. Soc. Lond. B, 1998,
353:1353-1362.
Egeth, H.
E., and Yantis S., Visual attention: Control, representation, and time
course, Ann. Rev. Psychol., 1997, 48:269-97.
Hilltrom
A. P., and Yantis S., Visual perception and attentionnal capture, Percept.
Psychophys., 1994, 55(4):399-411.
Hoffman,
D. D., Visual intelligence: How we create what we see. Norton, 2000.
Wade, N.,
An introduction: visual Perception, Michael Swanston, N.Y. & London,
Routledge, 1991.
Zeki, S.,
An exploration of art and the brain, Oxford University Press, 2000.
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