The Perceptual Process: 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). 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. PERCEPTION
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… 1. Organization PERCEPTION
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? Closure 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. PERCEPTION
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. Irradiation PERCEPTION
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. PERCEPTION Irradiation
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 brain’s 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. 2. Meaning PERCEPTION
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. Pattern and Structure 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. PERCEPTION
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. The Paradigm of Symmetry PERCEPTION Click image to view white figures.
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. PERCEPTION The Paradigm of Symmetry Click image to view black figures.
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. PERCEPTION
Illusion versus Reality PERCEPTION 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. Escher’s impossible figures.
PERCEPTION M. C. Escher Master of Illusion, Maurits Cornelis Escher is famous for his drawings of impossible structures such as this 1958 lithograph entitled Belvedere.
Summary: The Perceptual Process 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. PERCEPTION
We’ve 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