And the Nature of Perception

1
And the Nature of Perception
VISUAL ART
2
Part I Perception
3
The Perceptual Process
PERCEPTION
Perception is awareness of the world around us.
It is derived from information supplied by all of
our sensory receptors, of which vision is
foremost.
Although perceptions are unique to each
individual, the biological and mental processes
by which they are formed are the same for all
normal human beings.
Visual perception is a pattern-making process. It
involves only two primary functions (1)
Organization (structure) and (2) Meaning
(recognition).
4
PERCEPTION
1. Organization
Organization has to do with separating figure
from ground. A figure is what we look at.
Everything else is ground. The brain employs
several techniques for organizing the visual
field
5
PERCEPTION
Closure
Using a process call Closure, the brain seeks to
follow lines and contours until they enclose an
entire shape creating a figure. Even if there are
breaks in the contour, the brain will fill in the
missing parts and enclose the shape. Do you see
a triangle?
6
PERCEPTION
Edge
Our brains separate figures from ground, and from
each other, by edge to become the focus of our
attention. To identify an edge, the brain employs
a psychological principal called irradiation,
accentuating the perceived contrast between
elements in the visual field.
7
PERCEPTION
Irradiation
On this grid, the small gray areas seen at
intersections of the white lines are strong
evidence of irradiation. The brain is forcing the
edge to be sharper. The white background is seen
brighter adjacent to black squares than at
intersections where it is next to itself.
8
PERCEPTION
Irradiation
The irradiation process is amplified when we
darken the white bars where the brain tries to
lighten them. Now the small gray areas appear
almost as black spots.
9
PERCEPTION
2. Meaning
The perceptual imperative is linked to the
strongest biological drive we possess the
instinct for self-preservation. One of the
foremost properties of perception is the brains
insistence on creating patterns that hold
meaning, disregarding virtually everything that
it does not immediately recognize. This process
has been honed over millions of years and is
fundamental to natural selection and survival in
a hostile environment.
10
PERCEPTION
Pattern and Structure
Concentrate on this pattern of triangles. Within
moments they begin to group and regroup in
differing formations of varying size as the brain
frantically searches for meaning. Some seem to be
lighter, some darker than others.
11
PERCEPTION
The Paradigm of Symmetry
All living creatures appear to have symmetry.
Elements that are seen as symmetrical stand out
as having the potential to be living creatures.
When we were hunter-gatherers, a symmetrical
form hidden in tall grass could be perceived as a
predator or food.
12
PERCEPTION
The Paradigm of Symmetry
One tends spontaneously to perceive symmetrical
patterns as figures and non-symmetrical forms as
ground. Symmetry possesses visual weight because
we see it as a characteristic of living
creatures. In the patterns at left it is the
symmetrical black shapes that stand out as
figures.
Click image to view white figures.
13
PERCEPTION
The Paradigm of Symmetry
One tends spontaneously to perceive symmetrical
patterns as figures and non-symmetrical forms as
ground. Symmetry possesses visual weight because
we see it as a characteristic of living
creatures. In the patterns at left it is the
symmetrical white shapes that stand out as
figures.
Click image to view black figures.
14
PERCEPTION
Illusion versus Reality
Are these figures rotating? Much of what we
think we understand is illusion. For all of us,
it is this illusion that is reality. The
physical and perceived worlds are very different.
Yet both are real.
15
PERCEPTION
Illusion versus Reality
a Hering Illusion, first published in 1861
raised a question among physicists and
astronomers about the reliability of visual
observations. Both red bars are perfectly
straight. b Müller-Lyer Illusion. The vertical
lines are the same length. c One of M. C.
Eschers impossible figures.
16
M. C. Escher
PERCEPTION
Master of Illusion, Maurits Cornelis Escher is
famous for his drawings of impossible structures
such as this 1958 lithograph entitled Belvedere.
17
SummaryThe Perceptual Process
PERCEPTION
Perception, in its most rudimentary form,
operates at the survival level. Our senses
deliver raw data to the brain. In turn, our
brains utilize that data in ways that protect us
from harm, obtain food and reproduce. Our
perceptual responses have been created by natural
selection biological adaptations over hundreds
of thousands of years. Much of what we perceive
as real is actually visual gymnastics being
performed in the brain.
18
Weve seen how the brain has evolved neural
processes which enhance the perception of objects
in the visual field. Honed over hundreds of
thousands of years, these processes have helped
to ensure our very survival.
Please view Part II