Eidetism

EIDETISM (from the Greek eidos—image, contemplation, idea), a special psychic phenomenon close to figurative memory, consisting in the preservation of the image of an object for a long time after its disappearance from the field of vision. In the literal sense of the word, this is the vision of an absent object and constitutes the basis of visual eidetism. Similar images of other senses are also possible: auditory, olfactory, etc.; visual ones have been predominantly studied. Those people who possess the ability to have such images are called eidetics. For the first time, the phenomena of eidetism were described by the Austrian scientist Urbantschitsch in 1907; he called them subjectively optical intuitive images (Anschauungsbilder—A. B.) and considered it necessary to distinguish them from simple representations, since they reproduce a visual impression with a distinctness similar to a hallucination. Urbantschitsch's discovery remained neglected for many years; psychologists treated it as a rare phenomenon; only when the German psychologist Erich Jaensch and his pupils at the Marburg Psychological Institute subjected eidetism to special study and clarified its psychological significance did interest in this phenomenon spread worldwide, and everywhere people began to test eidetic phenomena and discuss the theoretical constructions of Jaensch and his school. According to Jaensch's teaching, eidetic images (a name given to this phenomenon by Jaensch) differ from ordinary visual memory in that the subject possessing them (the eidetic) does not reproduce them in his imagination, but continues to actually see them: the represented image is literally projected onto the visual field of the physical organ of vision of the eidetics in such a way that a corresponding adaptation of vision to the perception of this image occurs; they can be compared most closely to the slides of a projection apparatus. Some eidetics see this image with open eyes, others with closed, but even in the latter case, the impression of a perspective position is characteristic—the image is seen as if at some distance. Jaensch encountered this phenomenon mainly in adolescents. Elementarily, this ability is discovered in the following way: the subject is offered a small picture with complex content on a gray screen; after 20–30 seconds of exposure, the picture is removed, and the eidetic on the empty screen continues to see the shown picture and is able to convey all the details that were on the picture, indicating their coloring and location. According to Jaensch's thought, at the basis of eidetism, as well as at the basis of all memory processes, i.e., trace excitations, lies the inertia of nervous excitation: nervous excitation lasts even after the stimulus directly acting on the eye has been removed. Having at its basis the process of inertia of visual excitation, eidetism turns out, however, not to be an elementary physiological, but a complex psycho-physiological phenomenon. Two main forms of memory images are known: afterimages (Nachbilder—N. B.) and images of representation (Vorstellungsbilder—V. B.). Afterimages are well studied in psychophysiology and represent a universal phenomenon: if one fixes the eyes on some colored figure, e.g., a cross, a square, and then transfers the gaze to a white or gray surface, one can see the same figure only in the complementary color; thus, if the main figure was red, its afterimage will be green, and so on. As for images of representation (V. B.), they are the basis of our memory in the usual sense of the word: these are trace excitations that are sometimes more vaguely, sometimes more brightly renewed in our brain, but which differ significantly from afterimages. Between these two forms of memory images are wedged intuitive, or eidetic images (A. B.). They occupy, as it were, an intermediate place between afterimages and images of representation, approaching in individual persons sometimes the former, sometimes the latter. Some researchers were inclined to identify A. B. and N. B., but their difference lies in the fact that N. B. are in complete dependence on the movement of the eye, while A. B. are more independent; A. B. gives an image predominantly in a positive color, obeys all the laws of perception, is formed from the fixation of a more complex object, but can also be formed without fixation, completely spontaneously, or at the will of the eidetic himself. In this latter case, A. B. come close to V. B., but there is also a great difference between them: A. B. possess a large number of non-essential details, bear a corporeal character, and in their vividness approach perceptions. All these indicated mental processes—N. B., A. B., V. B.—are processes distinct from each other, but they all form a continuous ascending series of memory images that are sometimes practically difficult to separate from one another. By comparing A. B. so closely with N. B. and V. B., Jaensch wanted to draw attention to the fact that this is not a pathological property, but a physiologically and psychologically normal phenomenon. For him, eidetism is a completely regular and necessary phase in the development of memory, a phase through which all children pass. The development of memory, according to Jaensch, proceeded in the following form: the initial stage in the development of memory is the stage of the eidetic image, or undifferentiated unity, which through differentiation turns, on the one hand, into perception, and on the other, into representation. In the child's psyche, which is still only taking shape and has not completed differentiation, there is no clear division between perception and representation, and operating with eidetic images seems a direct necessity there. This phenomenon does not occur in a completely identical form in all children—it exhibits various stages of its development and various degrees of brightness. Jaensch distinguishes 5 such stages of the development of eidetism—from a brightly expressed phenomenon in gradual gradation to a latent state. By latent eidetism, Jaensch means the presence of this form of memory, but only in a hidden form and discoverable only indirectly. But even in the latent state, eidetism has an effect on the entire mental life of its possessor. A. B. exhibit an essential connection with both the activity of perception and the activity of thinking, especially at the early stages of the development of the psyche; A. B. arising from previous perceptions of given objects are mixed into the mechanism of visual perceptions. Helmholtz already posed the question of why objects retain their relative constant size when removed from the eyes; he explained this by an unconscious inference or the action of memory. Jaensch's research fully confirmed his assumption. The role of memory here is played by A. B.: thanks to their addition to direct perception, the possibility is created of seeing things with relative constancy; the image of an object on the retina of our eye decreases in proportion to the removal of the object from the eyes, while the eidetic image, on the contrary, grows as it moves away from the eyes; the magnitude of the real object perceived by us is, as it were, an average magnitude, which is obtained as a result of the joint action of the real decreasing stimulus and the increasing eidetic image. Jaensch asserts that the entire world of our perceptions is built on the addition of eidetic images to real stimuli. Eidetic images also have an effect on the activity of thinking. Thanks to the plasticity of their images, eidetics can switch certain intellectual tasks into optical images. This gave Jaensch grounds for the assumption that the solution of practical tasks by higher apes, described by Köhler, also occurs with the participation of eidetic images. But in eidetics, Jaensch also singles out more complex processes of uniting and fusing images, similar to the formation of concepts in abstract thinking: a concept in an eidetic is formed not from a simple mixture of individual images and the selection of common parts—a dynamic schema, a dynamic image arises in him, in which all individuals are preserved in an eidetic synthesis. Jaensch calls this form of concept formation fluxion. He also singles out another form of concept formation—meaningful composition: from various images, features are selected that together give the possibility of a new meaningful figurative construction. Eidetic images also have a great influence on the activity of imagination: the eidetic combines images of past experience in a vivid plastic form. It should be noted that the influence of emotional experiences is very great in the occurrence of A. B. The experiment with eliciting voluntary A. B. is more successful if the eidetic has an internal interest in the object; the analysis of spontaneously arisen A. B. can reveal the ideals of eidetics and their special interests. For Jaensch and his pupils, eidetism is an inevitable stage of development for the age of 8–15 years, although not everyone possesses an equally vivid ability. Jaensch's pupil, Kroh, found that the number of brightly expressed eidetics among children in Marburg is 40%; this figure can be accepted for the whole of Central Europe. The youngest age at which the eidetic ability was experimentally discovered was 6 years; children younger than this age cannot sort out their experiences. The highest point (acme) of eidetism falls on 14–15 years, and subsequently inhibition develops, which leads to the disappearance of this ability.

Among adults, Kro finds 7% of eidetics. The number of eidetics among children in the USSR has not been established. The phenomena of eidetism show a great dependence on locality, geographical conditions, individuality, age, and constitution. Eidetic images themselves turn out to be different in character for different people. It was natural for researchers to look for typological features among them. Research in this direction was carried out by the brother of E. Jaensch, the physician-therapist W. Jaensch; he identified among eidetics two completely diverse types of individuals, with different eidetic images and, accordingly, with a different physical and psychological structure of personality. One he calls the tetanoid or T-type; its pathological expression is tetany. In its somatics, one's attention is drawn to sluggish facial expressions, a dull gloss of the eyes, clumsiness or, conversely, calculated pedantry of all actions. On the neurological side, there is an increased mechanical and galvanic excitability of all peripheral nerves (motor, sensory, and perceptual); Chvostek's sign is always present, and there are complaints of cramps in the calf muscles, in the foot, and of various paresthesias. Phobias, talking in one's sleep, night terrors, and somnambulism are frequent. After-images of this type approach negative after-images, i.e., they are colored in the complementary color, and arise mainly under the influence of visual stimuli; they show little connection with mental life, with imagination, and emotionality; the images themselves are perceived by the T-type as something alien and obsessive and show a greater dependence on physiological and sensory factors than on psychological ones, i.e., on the brightness of the drawing itself, on the duration of fixation, lighting, etc.; the type possessing these images is withdrawn, absorbed in themselves, passive, sluggish, and prone to depression. The other type is the basedowoid, or B-type; this is a psychophysiological constitution, the extreme expression of which is found in the clinical picture of Basedow's disease; in normal variants of this constitution, one distinguishes, as it were, attenuated symptoms of the same personality makeup and body structure. This type is characterized by symptoms usually observed with an increased function of the thyroid gland; it is distinguished by psychovegetative excitability, pulse variability, and vasomotor phenomena; even in appearance, it can be distinguished by shiny eyes, exophthalmos, general easy excitability, etc.; tachycardia and increased sweating are noted; at times the thyroid gland is enlarged. Its after-images approach mental representations, are colored according to the primary image, and show a dependence on emotional life and imagination; they are dynamic and subjectively pleasant to the person experiencing them, since they are entirely fused with the interests of their personality and they readily speak about them. Psychologically, this is a syntonic type, easily mobile, and changing in mood. Pure types are rare; mixed types with a predominance of the features of one or the other type are more common. Many studies have shown that the phenomena of eidetism are in direct dependence on chemical action on the organism. Thus, the T-type upon taking calcium shows a weakening of eidetism. In the construction of W. Jaensch's types, the influence of Kretschmer is visible, although Jaensch is negative towards Kretschmer's morphological classification scheme, considering it too crude and based on shallow scientific premises. In contrast to Kretschmer's correlation scheme, he wanted to give a functional consideration of the human personality. But following Kretschmer, he also proceeded from certain nosological units and arrived at the norm: the T-type is close to the angular, autistic schizoid, and the B-type to the harmonious, syntonic cycloid. In literature, the indicated typological division of eidetics is subjected to the greatest criticism. Experimentally, the correspondence between the constitutional types B and T and the signs of after-images characteristic of both types is not confirmed. Eidetic research, which led E. and W. Jaensch to the doctrine of constitutions, introduces a genetic point of view into this research itself. E. Jaensch, using the data of Lévy-Bruhl, establishes the existence of an eidetic phase in primitive peoples. In the process of the historical development of the psyche, the visual type is chronologically earlier and represents the original undifferentiated unity of sensory experience, from which, on the one hand, perceptions and, on the other hand, representations are separated. The eidetism of primitive peoples explains certain features of primitive language (which is striking in its wealth of concrete words), art, the content of many sagas and myths, as well as the animization of nature. Researchers compare young eidetics, who easily projected pictures onto the blue sky or onto single-colored clouds, with superstitious people of the past who, under the influence of their suddenly arisen images, populated the sky with supernatural beings; the fact that eidetism should rather be sought on the basis of primitiveness is proved by observations according to which eidetics were encountered more often in the countryside than in the city. The fact that eidetism is an early phase of development is also indicated by the circumstance that among adults it is encountered rarely (7%), and if it is encountered, then, according to Jaensch, they also exhibit certain features of an undifferentiated psyche: their perceptions, representations, and even higher forms of thinking are plastic; sensory experiences predominate over abstract-logical constructions, and artistic, figurative thinking is more characteristic of them; there is a large percentage of eidetics among artists. For psychopathology, eidetism may be of interest in that a number of hallucinatory experiences of patients can be linked to their eidetic predisposition. E. Jaensch at the congress in Cassel in 1925 demanded that in the doctrine of hallucinations and pseudohallucinations, along with medical data, eidetic studies should also be taken into account. All those cases where hallucinations are of a persistent, plastic character may give rise to the assumption that the hallucinators are eidetics. In cases of delirium tremens, the presence of eidetic phenomena was discovered in patients after an attack, which disappeared upon recovery, and their repeated return testified to a new approach of the attack (observations of Prof. E. Popov, reported at a conference in Kiev in December 1934). In neurotic children, eidetic images before the onset of sleep have the character of hypnagogic hallucinations, and unpleasant eidetic images of an obsessive character can be a source of fears for them, predominantly in the evening and night hours. The sphere of influence of eidetism is quite large and significant: under its influence, the traditional doctrine of memory, perception, the concrete type of thinking, recollection, imagination, and concept formation in adolescence is being reconstructed. But W. Jaensch did not want to limit himself simply to the analysis of eidetic images, with which he began; he strives to turn eidetism into a whole worldview: he and his students try to see in eidetism a primary psychic phenomenon that subsequently determines the entire psyche. This leads Jaensch to the construction of an idealistic doctrine of the autonomous development of mental processes outside of any connection with concrete historical conditions; conversely, Jaensch tries to derive complex social phenomena from elementary mental functions. Jaensch calls his philosophy psychonaturalism, or realistic idealism; the reactionary character of his idealistic tendencies has manifested itself especially clearly recently, when he openly took the side of fascism, being one of its ardent apologists.