Lecture
Gestalt psychology played an enormous role in the emergence of the psychology of cognition. Historians and theorists of psychology usually focus their attention on the subject area with which the Gestalt psychologists were concerned and on the principles of the gestalt». «Gestalt», translated precisely from German, means the form of an object, a holistic object (a system).
The Gestalt psychologists extended the principles of systemic organization to all
levels of cognition: from perception to thinking, and further — to the motivation
of the personality, communication, and social-psychological phenomena. External stimulation is instantaneously (simultaneously) organized into a holistic structure (a percept) by an active dynamic system — the brain. The image, however, is holistic not because the laws of the brain's operation are such, but because
the principles of perception are present in the observed objects themselves, held M. Wertheimer [Werthemer, 1912]. Later the German psychologist W. Köhler [Kohler, 1929] put forward the principle of isomorphism: there is a one-to-one correspondence between the structure and dynamics of the external
observed world, the cerebral cortex, and subjective reality.
The whole precedes the part; the properties of a system determine the properties of its elements, and not the reverse. The principle of isomorphism served the outstanding Russian psychologist L.M. Wekker [2000] as the chief premise for creating an original theory of cognitive processes.
The founder of ecological psychology, J. J. Gibson
[Gibson, 1961], was influenced by the works of the Gestalt psychologists, chiefly K. Koffka [Koffka, 1935]. Gibson's first work on perception appeared
in 1950 and was devoted to the perception of space. In it Gibson set out his ground theory of space perception. He proposed that the gradient
of the texture of the ground is the principal cue to depth and corresponds to gradients of retinal excitation. He then advanced the conception of ecological optics. Earlier, psychologists adhered to the views of Helmholtz,
Wundt, and Wertheimer, holding that a person does not cognize the physical world
around him directly. He assembles («integrates») the successive
fragmentary and incomplete images into a single dynamic
picture by drawing on past experience, anticipations, and so on.
According to Gibson, there is enough information in the visible world for the formation of a visual image. He introduced the concept of the perceptual invariant —
a property of the stimulus that remains unchanged under changes occurring in the observer and the environment. Invariants may be dynamic
or structural.
Another crucial concept introduced by Gibson is the affordance, a purpose, an offering. It describes the relation between organism and environment. Affordances can be perceived directly, without analysis, without recourse to
memories, and so forth. They constitute certain dispositions of the environment with respect to the organism, they determine its behavior, and they are defined solely by the physical properties of the object.
Gibson's theory, despite being criticized by many researchers,
revealed the inadequacy of earlier conceptions of the nature of human
cognition. After Gibson's work it became clear that the external, knowable
world should be described in psychological language, adequate to the tasks of psychological science. The environment acting on a person actually and directly
is a system possessing a structure of its own.
In their laboratories researchers began to create not artificial but ecologically valid stimuli. Gibson's conception, at first glance contradicting the point of view of the founders of cognitive psychology, in fact did it a great service.
One of the chief critics of the conception of ecological optics was the American psychologist David Marr [Marr, 1982].
He was engaged in computer modeling of perceptual processes. In his monograph «Vision»
Marr argued that Gibson's theory was insufficiently elaborated. Gibson does not specify what «direct perception» is or how to model it. It is unclear how invariants are to be extracted from the physical environment, and so on. Marr proposed his own model of stage-by-stage information processing. At the first stage, the «primal sketch» is obtained by organizing the intensities of stimulation on the retina in accordance with the spatial distribution of intensities. At the second stage, the orientation and general depth of the visible surface are formed (the 2 l/2-D image). At the third stage, a three-dimensional model of the scene is created, independent of the orientation of the pattern of stimulation on the retina.
Marr's conception is cited as an example of the information-processing approach to solving the problems of cognition. This approach will be examined in subsequent articles.
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