Psychophysical level

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Psychophysical level, which is illustrated by the demarcation between the blue and red zone.

The psychophysical level is first of all a concept of rational psychology which seeks to describe the boundary between conscious and unconscious body processes in the brain, cf. → mind-body problem . In this way, both areas can both conceptually be delimited from one another and connected with one another by showing relationships, cf. → psychophysical correlation . So that the delimiting term is also a localization idea ahead as in the neurology usual ist.- Without such purely conceptual distinction is for. B. a physiologically oriented perception psychology is not possible, see also the basic concepts of perception theory . Psychophysical level is a theoretically conceived boundary line construction and is therefore one of the so-called psychophysical models, see also → Psychophysics . Such models attempt to connect the physical and psychological topology with one another, even if the area of ​​the CNS in which the physiological processes of consciousness take place cannot yet be precisely defined.

To the history of research

The concept of the psychophysical level usually presupposes a hierarchical functional structure. This is the subject of a level or layer theory , as represented, for example, by Pierre Janet (1859–1947) in his “psychologie de la conduite”. The so-called mental tension of a person corresponds to a certain hierarchical level. Who has a high level of mental tension, who finds it easy to carry out high-ranking actions frequently and conscientiously. A gradual lowering of this level ( abaissement du niveau mental ) occurs in neuroses and psychoses . Janet criticized psychoanalysis by pointing to its origins in French psychology. The term “psychophysical level” was first used by the Gestalt psychologist Wolfgang Köhler (1887–1967) in 1920 in the course of his brain-physiological Gestalt theory (→ isomorphism ). Wolfgang Metzger (1899–1979) took up this research in 1941 and carried it on. It assumes that everything psychic is conscious and the conscious is psychic. Transitions and connections between consciousness and the unconscious are not taken into account.

Research goals

From an empirical-psychological point of view , this is a choice of terms that is aimed at a presumed anatomical-topographical description of neuronal states with or without quality of consciousness. This is not only about fixed and therefore topographically clearly defined structures of the brain, but possibly also about purely functional forms of state, i.e. flowing boundaries that e.g. B. depend on attention or on phylogenetic and ontogenetic factors. It can be regarded as a certain and also immediately obvious fact that not all nervous activities can be registered by our consciousness and certainly cannot be controlled. So are z. B. In a perception process, only the neuronal processes in the cortical end section are accompanied by consciousness. The processes in the sense organ and in the pathways, on the other hand, lie outside the psychophysical level.

Physiological question

Many nervous processes are controlled automatically and therefore unconsciously, cf. Vegetative . The question arises as to which brain regions are responsible for the state of wakeful consciousness and which are to be regarded as essential for this. "Only those processes in the nerve tracts and generally in the nervous system of physical consciousness are capable of consciousness and can constitute a perception or sensation that take place on the psychophysical level." The psychophysical level is therefore to be understood as a self-contained boundary line within the brain. All nervous processes taking place outside of this borderline can thus be described as "transcendent of experience". It goes without saying that this boundary line is not to be regarded as a clearly defined anatomical structure. Rather, it must be viewed as flowing depending on the degree of brightness of consciousness ( vigilance ), fatigue, attention or motivation in a certain situation. Since it therefore depends on subjective factors, it must be regarded as an object of perception physiology and perception psychology . The psychophysical level is therefore the basic neurophysiological term for what neuroanatomy describes with the animal nervous system . It can therefore also be assumed that there are both clearly defined and flowing criteria for the intended objectification of consciousness.

Empirical confirmation of the psychophysical model

As confirmation of the psychophysical model, results from electroencephalography (EEG examination) are to be regarded as a neurophysiological examination method. It was first practiced by Hans Berger in 1924 and later scientifically described and evaluated. One of the fundamental facts and experiences gained from this procedure is the correlation of the so-called α-rhythm of 8–12 Hz (alpha rhythm) with the conscious consciousness. The so-called α-waves can preferably be registered via the occipital, temporal and parietal leads, i.e. H. about all those brain regions that are known to be the exclusive seat of the sensory projection centers , cf. Sensorium . In contrast, slower waves from the θ and δ bands (<8 Hz) dominate during sleep. Already during the sleep stage (B-stage) the α-waves disappear from the brain wave image. By taking medication that dampens and calms the consciousness, β waves (> 13 Hz) are registered over the frontal regions of the brain. These include a. Barbiturates , carbamides , carbamates , benzodiazepine derivatives , primidone , trimethadione and meprobamate . Also in epilepsy , which is known to be associated with the risk of loss of consciousness in an epileptic seizure, specific brain wave processes are often recorded, the so-called seizure potentials .

further reading

  • FS Rothschild: The symbolism of the brain structure . 1935.
  • DE Wooldridge: Mechanics of brain processes . 1967.
  • SA Sarkissow: Outline of the structure and function of the brain . 1967;
  • Hartwig Kuhlenbeck : brain and consciousness . 1973.

Individual evidence

  1. ↑ a b c Wilhelm Karl Arnold et al. (Ed.): Lexicon of Psychology . Bechtermünz, Augsburg 1996, ISBN 3-86047-508-8 ; (a) on tax authority “level, psychophysical”: Col. 1484; (b) on Stw. “Janet, Pierre”: Col. 1033 ff .; (c) as (a) and (b).
  2. ↑ a b Georgi Schischkoff (ed.): Philosophical Dictionary . Alfred Kröner-Verlag, Stuttgart 14 1982, ISBN 3-520-01321-5 , p. 562
  3. ↑ Wolfgang Köhler : The physical shapes in rest and in the stationary state. A natural-philosophical investigation. Braunschweig, 1920.
  4. ↑ Wolfgang Metzger : Psychology . Development of their basic assumptions since the introduction of the experiment. Krammer-Verlag, Vienna 6 2001, ISBN 3901811079 , first edition 1941
  5. ↑ a b Olga Simon : The electroencephalogram . Introduction and atlas. Urban & Schwarzenberg, Munich 1977, ISBN 3-541-08221-6 ; (a) on the topography of the α-wave derivation p. 41 ff .; (b) on electrophysiological correlate of consciousness-depressing drugs p. 52.
  6. ^ A b c Walter Christian : Clinical electroencephalography . Textbook and atlas. Georg Thieme, Stuttgart 2nd edition 1977, ISBN 3-13-440202-5 ; (a) on the topography of the α-wave derivation p. 15 ff .; (b) on B stage of sleep p. 34; (c) on seizure potentials, p. 88 ff.

See also