Excerpts from
L.Kleine-Horst: "Empiristic theory of visual gestalt perception. Hierarchy and interactions of visual functions" (ETVG). Köln
2001, Part 1, II

The new way to solve the problem

1. The starting point

The starting point for our theoretical considerations is the following: I know which image of my surroundings is on my retina whenever I look at a certain object in my surroundings;  I know the "stimulus pattern". I know therefore in general which photoreceptor is stimulated by which luminance and by which wavelength. I also know what I experience under these stimulus conditions.

Contemporary vision research tends to focus on the neurobio- logical aspect. The neurobiologists believe in the possibility of understanding the foundations of perceptual experience through an immense use of equipment, personnel, money, and computers. They believe it is thus possible to solve the riddle of the relationship between stimulus and experience.

The neurobiologists do not seem to realize that it might not be possible to find the principle that governs perception through knowledge of the physiological mechanisms. In other words, the physiological mechanisms might be necessary but not in themselves sufficient conditions for visual perception. That the problem of the stimulus/percept relationship might not be possible to solve empirically also seems not to have occurred to them. At any rate, it is a fact that a solution has not been found despite all the empirical research that has been carried out. It is also a fact that the possible solution presented in this book is of a theoretical, not empirical nature. Among the new observations I have made, there is not one that has been essential for the development of my theories. My theories are nothing but a new interpretation of long-known facts.

Traditional science focuses on physical matter and its physical functions. It is thus natural that it tends to focus on the brain, the intermediary between receptors and sensation. This approach, however, has not yet produced an acceptable theory of perception. The aim of this book is to ascertain just what takes place between the stimulation of the receptors and the emergence of a subjective perceptual configuration.

On one hand, I could accept the traditional view in respect to the path taken by light on its way to the receptors. On the other hand, I could also imagine to myself what I would perceive under certain sensory stimulus conditions, i.e. given a certain retinal image. I thought, however, that the physiological processes of the brain as presented in textbooks and handbooks were too complicated. I thought to myself: nature cannot be that complicated. Man evolved from less complex life-forms, and so did his visual system. I could not believe that such complicated mechanisms should have evolved solely for visual perception. I thought that the same should be possible in  only a small number of steps.

Since I was not made to understand the deeper processes of the brain as a student, I did not even try to explore this further, and took the brain to be a "black box" in that the unfamiliar gestalt perception system lies. I asked myself further: "How does this system have to be constructed in order for me to be able to see the stimulus source as I do, given a certain distribution of stimuli on the retina?", a question similar to that of Koffka (1935): "Why do things look as they do?". I phrased my question more precisely: "There are three-dimensional objects that are changing or not changing their location, colors and forms, and are moving or at rest in three-dimensional space, and are projected onto the retina. How must a system be designed so that I, using these two-dimensional retinal projections, that constantly change their location, color and form, can perceive exactly the objects being projected?" Additionally, one must consider that the objects, as projected on the retina, are crooked, warped and blurred, for the eye is a miserable camera, not to be compared with the top products of our optical industry.

I was right in my assumption that the visual system could not be that complicated. This system proved to be straightforward, even simple, if one considers what tremendously complex perception it is capable of. In this manner, I was able to crack the code of visual gestalt perception in a relatively short time (although it did take me a few years). This means I discovered the small number of steps necessary for visual perception.  A few basic assumptions, however, were necessary to do this, in particular the need for the further development of the Cartesian dualistic model of reality into a trialistic one (Kleine-Horst 1992d).

2. What is a "figure"?

The three-dimensional objects in our surroundings are projected on the retina as two-dimensional "figures". A theory of perception must be capable of explaining why we are able to perceive a three- dimensional object on the basis of this planar stimulus pattern. It has to be able to explain how we are able to perceive on the basis of the continually changing stimulus conditions on the retina, movement of bodies in a static world in that each thing has its own place, form, and color. I shall show the construction of this world of perception by means of a virtual ontogenesis or actual genesis.

 For now I shall leave aside both time relationships and the third dimension of spatial relationships. The source of stimulus is therefore a two-dimensional construct that is at rest in relation to its surroundings: a blob of light in dark surroundings, a stimulus source of   the   type  "moon   in   the   sky",    for   example.   The   moon  is  objectively three-dimensional but is so far away that we cannot perceive its three-dimensionality. The moon is in motion in relation to its optical surroundings but it moves so slowly that we may neglect this fact. This moon is experienced as a "figure", but what exactly is a "figure"?

 

Figure 1-3. Examples of "figures"

Every psychologist knows what a "figure" is. For other scientists this can be described with the help of the Fig.1-3. Each of these pictures is a "figure". In order to better understand the "nature" of a figure, we shall look at these pictures a little more closely and describe them. Figur A is a house. Stop! "House" is a name, a term. This figure means "house", "stands" for house, reminds us of a house; we have learned: this is what a house looks like. Just like A any figure can carry a meaning. Figure B can mean "square", Figure G "face", or "mask". Figure F can be a "drop of oil" or a "badly" depicted revolver. Please put aside the meaning of a figure, it does not belong to the idea "figure". Just perceive!

The figures look different; they each have a different form. B and C have the same form on the "outside", but they are different colors: B is black, C is white. C also has something on the "inside" that B does not have. B and F also look somewhat "similar". The similarity of these figures consists of their color and the lack of inner structure. The inner contours in D can be experienced as borders of partial fields, and moreover in their totality as a holistic property of the infield, as a hatching or texture.  B and F consist only of a black area, bordered off from the surrounding area by a sharp line. Figure E also has a borderline but this borderline is blurred, not sharp. A borderline that borders a figure off against all that surrounds it may be called an "outer contour". The lines segregating small fields within the "inner field" as in G or subdividing the entire inner field as in C, may be called "inner contours". The inner contours of figure G enclose  in turn   small  fields  and  border  these  off against   the   surrounding field, the "outer field". The figure contours can take on many different forms, that is why the figures themselves are many different forms.

 

Figure 1-4. System of material, functional, and phenomenal entities
for the static, two-dimensional figure-contour perception

Disregarding the forms and the meaning conveyed by form and color, one can say that every  picture in Fig. 1-3 is a "figure", i.e. a part of the total visual field, that is bordered off against the rest of the visual field by a more or less sharp contour.  Fig. 1-3H shows the general structure of the static, two-dimensional visual represen- tation of an "object in its surroundings". We could call this percept a "figure-outer field system" or an "inner field-contour-outer field system". Because this terminology offers opportunity for misunder- standings, "inner field" will be replaced by "infield" and in turn "outer field" by "outfield".We have now an "infield-contour-outfield system". Because of the symbols "i" for "infield", "c" for "contour", and "o" for "outfield", I call the "figure/outfield percept" also "ico-system".

 

3. The basic model of visual gestalt perception

The following presentation of my theoretical concept of visual gestalt perception is a rough outline, a skeleton that will be "fleshed out" later. The frame of reference of the ETVG is the Three-Sphere Four-Level Model of Reality and Personality, as roughly shown in Fig. 10-7. Fig. 1-4 shows the part of the trialistic model of personality that deals with the static, two-dimensional figure/outfield perception. The physical evolutionary level comprises the upper part of the material and the lower part of the functional sphere of being. Material entities ("sensory stimuli") that stand for inorganic matter impinge upon the (material) receptors that stand for the higher-level vital matter (VM, Y). This kind of matter does not immediately lead to (psychical) perceptual experience (PC), but only to (physical) sensory, or vital, functions (VF, Z). These sensory functions as well do not have gestalt phenomena (psychic consciousnesses, PC) as dependent correlates, since a phenomenal sphere does not exist at the physical evolutionary level (see also Figure 10-7).

The vital functions (VF) "somehow" actualize a hierarchy of psychic functions (PF), i.e. "gestalt factors", or "gestalt functions". These specific gestalt factors, in the functional sphere, produce in turn specific "gestalt qualities", in the phenomenal sphere (indicated in Fig.1-4 as horizontal arrows toward the ellipses). The symbols of factors and qualities will be explained later.

It is possible for more than one gestalt factor to be located at a particular hierarchy level. A gestalt factor is actualized by its specific "gestalt stimulus" (indicated by an arrow  pointing upwards) and then introduces its specific gestalt quality into the percept. The gestalt stimulus has to have a certain minimum magnitude, the "actualization threshold", in order for the actualization of the gestalt factor to be triggered. For example: in order for me to be able to experience the phenomenon "brightness difference" Dm', the magnitude of the gestalt stimulus "brightness difference" (corresponding only to a certain degree to the difference of luminance, or reflectance) has to be large enough to exceed the actualization threshold of the gestalt factor "brightness difference" Dm. In reference to the magnitude of the sensory stimuli, needed for the factor to be actualized by its gestalt stimulus, with all other actualizing conditions held constant, one can assign each gestalt factor a "relative actualization threshold" that corresponds in magnitude to the hierarchy level the factor belongs to; the higher the level, the higher the actualization threshold.

The aforementioned, along with a few other assumptions, yields the following model of visual "actual genesis" (Sander 1928) or "microgenesis" (Werner 1956), i.e. for the emergence and development of a visual percept. In the presence of sensory stimuli of increasing magnitude (from whose arrangement the specific gestalt stimuli result), starting with very weak sensory stimuli, the gestalt factors will be actualized one after the other according to the magnitude of their relative actualization thresholds, i.e. the order in that they are located in the functional hierarchy "from the bottom up". This discontinuous progression of the actualization of the gestalt factor hierarchy (within the functional sphere) results in an "actual genesis", i.e. step by step enrichment of the visual experience (in the phenomenal sphere). The other way round: starting from strong sensory stimuli, a weakening of the stimuli causes a regression of the actualization (i.e. a deactualization) of the hierarchically ordered gestalt factors "from the top down". This stepwise deactualization of the functional hierarchy has, as its dependent correlate, a step by step reduction in the perceptual experience, i.e. the "actual lysis", the counterprocess of actual genesis.

Not only the strength of the stimuli, but also the degree of attention influences the perception of objects. An increase in attention focused on an object leads to the actual genesis, a decrease leads to the actual lysis of the object's perception. Examples of "actual genesis" and its counterprocess are given in Part 6.

This basic model of visual gestalt perception, here concisely presented, will be elaborated on and differentiated in Parts 1 to 7.

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