L.Kleine-Horst: "Empiristic theory of visual gestalt perception. Hierarchy and interactions of visual functions" (ETVG). Köln
2001 Part 1, IV
Expanded model of gestalt perception
Let us summarize the process of gestalt perception using a slightly different model: Fig.1-13 shows the general schema for the actualization (or activation) of a gestalt factor. The schema is valid for every level of the visual hierarchy. The relationships between several gestalt qualities "X-1" (represented here by the broken arc) are the specific gestalt stimulus X that actualizes "its" particular gestalt factor X whenever its magnitude exceeds the actualization threshold of gestalt factor X. The functional process of the actualization of the gestalt factor X possesses a phenomenal correlate: the emergence of the gestalt quality X. This gestalt quality is then introduced into the existing percept, which until this point had gestalt quality X-1 as its highest-level gestalt quality: henceforth, there now exists a more complex, but nevertheless holistic, percept with gestalt quality X as its highest-level gestalt quality. (The ellipse indicates the holistic nature of the percept.)
Figure 1-13. General model of
information processing from any level X-1 of the visual gestalt factor hierarchy
to the next-higher level X.
In order to apply this model to gestalt factors Pml and those above, it is necessary to make a small correction in the region of the broken curve in Fig. 1-13: here it appears, as if gestalt stimulus X portrays the relationship between the gestalt qualities X-1, i.e. between the phenomenal experiences (depicted as ellipses). In Fig. 1-14 the relationships are presented somewhat preciser: even before the specific outputs of, for example, gestalt factor Pml produce the phenomenon Pml, the (functional) relationships between these (functional) outputs are used, to create the (functional) gestalt stimuli Dm and Dl. Equally, it is the relationships between functional and not phenomenal entities that make up the gestalt stimulus Gml (and so forth). Also the lowest gestalt stimulus (Pml) consists in - according to Fig. 1-14 - relationships between functions, however, in this case, not between psychical functions, but between physical (sensory) functions (Z) (see the connecting arc between two Zs in Fig. 1-14).
Figure 1-14. Special model of the information processing from level Z to level G und further to level Fl of the visual system
One can see also from Fig. 1-13 that the increasingly complex percept (ellipse) not only includes the percepts at the lower hierarchy levels, but also contains the relationships between these percepts. At the P-level, the Pml percepts stand purely functionally in a particular Dm and Dl relationship to one another; at the D-level, this relationship is perceived, i.e. the D percept is the holistic perception of "the Pml percepts in the relationships Dm and Dl". The perception of "the D percepts in the relationship Gml" takes place at the Gml-level, and so on for the higher levels.
Further relationships are depicted in Fig. 1-13: since at least those gestalt factors located at levels P to F of the hierarchy interact with one another (see Part 8), the gestalt factor receives input also from other gestalt factors, from factor W for example: an unspecific input of factor X is an unspecific output from factor W. Likewise there is an unspecific output of the gestalt factor X, and this output is, at the same time, an unspecific input of the gestalt factor W. All inputs and outputs of a gestalt factor are purely functional in nature. All perceptual processes that constitute an immediate basis of perceptual experience (in the phenomenal sphere) take place in the functional sphere. Two kinds of output must be distinguished: the "specific output" that leads to the emergence of a specific gestalt quality, and the "unspecific output" that is the unspecific input of another gestalt factor. It is thus possible that unspecific as well as specific inputs of a gestalt factor lead to the actualization of that gestalt factor and thereby to the production of its specific output, i.e. its specific gestalt quality. The specific gestalt stimuli (specific inputs) functionally differ from the unspecific inputs in that they consist of those relationships that have implicitly impressed themselves as memory contents (Part 4). These memory contents are actualized by subsequent identical or similar relationships (gestalt stimuli), and thus act as gestalt factors. Insofar as they are actualized by unspecific gestalt stimuli, they develop a "formative effect" (Part 2), i.e. they allow "illusions" to arise, they "deceive" us about the actual structure of the objects in our environment. Gestalt factor W is activated by itself ("selfamplifying effect"), by its own gestalt stimulus W, and by any gestalt factor X, when there are adequate X-stimuli.
The degree of actualization of the visual factor hierarchy correlates positively with both the strength of the sensory stimuli and the degree of attention paid to the object perceived.
Here are some definitions based on the previously portrayed concept:
Gestalt factor X is a functional variable that, when actualized by the gestalt stimulus X, introduces the gestalt quality X into the holistic percept.
Gestalt quality X is the dependent phenomenal correlate of the (actualized) gestalt factor X.
Activation of the gestalt factor X is the effect of the gestalt stimulus X on the gestalt factor X
Actualization of the gestalt factor X is its activation beyond the actualization threshold. It is identical to the introduction of the gestalt quality X into the percept.
Specific gestalt stimulus X of the gestalt factor X at Level n is a certain relationship between activated factors at Level n-1.
Unspecific gestalt stimulus W of the gestalt factor X is the specific gestalt stimulus for the gestalt factor W that is able to coactivate the gestalt factor X.
Actualization threshold of the gestalt factor X is the minimum magnitude of the activation of the gestalt factor X necessary to actualize the gestalt factor X.
The ETVG represents a special elaboration of the trialistic four-level model of reality and personality (Kleine-Horst 1992d) for the visual domain. The second and the third evolutionary level, body and psyche, are involved in visual perception. Each of the two levels encompasses two spheres of being: the body encompasses the material and functional spheres of being, and the psyche encompasses the functional and phenomenal spheres. The physical (sensory) functions are dependent correlates of the hierarchically structured (physical) matter; the psychic phenomena are dependent correlates of the hierarchically structured psychic functions. The hierarchy of psychic functions (or factors) is built upon the hierarchy of physical functions (or factors).
According to the findings of the earlier psychophysicists and to the (later so-called) "constancy hypothesis" of the "Elementarists" regarding the existence of set ("constant") stimulus-experience relationships, the brightness should correspond to the luminance of light impinging onto the retina, and the color should correspond to the wavelength. Furthermore, the perceived location (spacial direction) should correspond to the position of the stimulated photoreceptor within the retina, and the time of the "sensation" should correspond to that of the stimulation.
According to the findings of the early Gestalt psychologists, this is not the case. Instead, all kinds of deviations from the perceptual experience one might expect, based on the "constancy hypothesis", can occur. For over 100 years researches on visual perception occupied themselves with the question why these deviations occur - a question that has remained up until now unanswered. The ETVG gives the first detailed answer to this question. The partial answer given in Part 1 is as follows:
1. The four perceptual aspects mentioned above cannot be derived immediately from the four sensory aspects (luminance, wavelength, location, time), as there is no immediate correlative connection between the material sphere, to which the light stimulus and the receptors belong, and the phenomenal sphere of experience. Only the four sensory factors of the functional sphere correlate with the four aspects of the sensory stimuli in a one-to-one relationship.
2. The sensory (physical) factors are factors related to material, the output of which is changed, or overlaid, by a psychic factor (gestalt factor, gestalt function). Certain relationships between the outputs of the sensory factors serve as the gestalt stimulus that actualizes this lowest factor (Pml). In turn, a certain relationship between the outputs of the gestalt factor Pml is the gestalt stimulus for the gestalt factors at the next-higher level. This relationship is then repeated for every higher factor level.
3. Each gestalt factor relates to a specific visual experience - a specific gestalt quality, i.e. this particular gestalt quality emerges with the actualization of "its" gestalt factor. The "sum" of all gestalt qualities constitutes the percept, that is always holistic.
4. The most important percept is the "figure", the perceptive representation of an object. This object is optically projected onto the retina where it creates the relevant sensory stimulus. The figure is a relatively small section of the total visual field. It is usually set off against the remaining visual field by a more or less sharp borderline ("contour"), and where the remaining field usually has a different brightness or color. (The shape of the figure does not belong to the concept "figure", in the strict sense of the word.)
5. The contour of the figure, as the representation of the object's edge, depends on six gestalt factors that exist in the following five-level hierarchical sequence, described as "bottom-up": the factor "brightness at a location" (Pml), the factor "brightness (or color) difference" (Dm) and, at the same level, the factor "location difference" (Dl), the factor "lateral brightness gradient" (Gml), the factor "lateral line" or "borderline" (Ll), and the factor "lateral closedness" (Fl).
6. Each gestalt factor has been assigned a symbol (given above in parenthesis) by that it can be identified. The same symbol is assigned to the gestalt stimulus that actualizes the gestalt factor, and to the gestalt quality produced by the actualized gestalt factor.
7. The actualization of this gestalt factor hierarchy occurs according to the magnitude of the gestalt stimulus. The gestalt stimulus must be of a certain minimal magnitude ("actualization threshold") to be able to actualize the factor.
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