Peter Kruse

Frontal gamma-band enhancement during multistable visual perception.

The aim of our study was to find out whether an increase in the gamma band may be related to the reversal phase during viewing of an ambiguous pattern. The present study describes the significant gamma band (30-50 Hz) activity increase in EEG during states of perceptual switching (reversal state). In our experiments the multistability was induced with an ambiguous stimulus pattern, known as stroboscopic alternative motion (SAM). The investigations carried out in 11 subjects included a measuring strategy with three different experimental conditions: (1) recording of spontaneous EEG as baseline; (2) recording of the EEG during naive observation of the ambiguous pattern; (3) recording of EEG during active observation of SAM. The results indicate that the multistable perception is one of the multifold cognitive processes giving rise to 40 Hz enhancement in the entire cortex. The most significant 40 Hz enhancements were measured in frontal areas and can reach increases of 40 to 50% in states of naive and active observations of SAM, respectively, in comparison to spontaneous EEG recordings. The results indicate that the increase of frontal gamma band is related to the destabilization of the perceptual system when viewing multistable patterns.

MULTISTABLE VISUAL PERCEPTION INDUCES A SLOW POSITIVE EEG WAVE

Seven subjects observed a multistable pattern (stroboscopic alternative motion: SAM), and were instructed to press the button immediately after perceptual switching with the aim of detecting some neurophysiological parameters of EEG activity. Our results indicate that the EEG changes observed during multistable perception are similar to the family of event related potentials which we called perceptual switching related positivity. Furthermore, the frequency component of this potential has a similarity to the frequency content of stimulus locked P300.

Instability and Cognitive Order Formation: Self-Organization Principles, Psychological Experiments, and Psychotherapeutic Interventions

The transfusion of basic principles of self-organization theory to cognitive processes is a necessary and promising task of general and applied psychology. For historical reasons and because of practical evidence self-organization concepts have already gained considerable acceptance in psychotherapy. But the attempt to link the basic theoretical principles with cognitive phenomena and with concrete therapeutic interventions is still in its infancy. The interventions often seem to be more a product of the therapists intuition than a consistent deduction, and in experimental psychology only few examples of phenomena analysed in terms of self-organization theory can be mentioned.

Attractors and perceptual field dynamics of homogeneous stimulus areas

SummaryThe phenomenon of the wandering point on a blank sheet of paper in serial reproductions is the starting point of an investigation of the perceptual field structure of homogeneous stimulus areas; 609 stimulus points distributed regularly in 21 rows and 29 columns on a DIN A4 sheet were presented successively to 10 subjects and had to be reproduced immediately afterwards in order to establish empirical vector fields. These were subjected to vector-analytic procedures. A method for the decomposition of the measured vector fields into partitions from gradient potentials and circulation potentials is demonstrated. The gradient potentials of the empirical vector fields revealed a highly regular structure with four point attractors near the corners of the sheet. A model calculation of the wandering point in this potential landscape showed results comparable to the empirical phenomenon. The results are discussed in favor of Gestalt theory and against direct perception.

Self-organization aspects in the temporal formation of movement gestalts

Abstract The theories of gestalt and self-organization are described as converging on a perspective of order formation as an autonomous process in cognitive systems. In contrast to indirect and direct models of perception and action, a joint reference to gestalt and self-organization theory is suggested to provide a non-reductionistic understanding of phenomena of order and stability in psychology. In section 2, the gestalt theoretical concepts of transposition, non-summativity and economy are applied to motor behaviour - in particular the temporal organization of skilled motor actions. In section 3, these concepts are pursued experimentally in three pattern reproduction experiments. The results indicate that complex cyclical movements with changing amplitudes do not tend towards a strict periodicity, instead the spatiotemporal movement form appears to emerge according to an optimal conduction of already existing kinetic energy along the movement cycles.

Gestalt theory and synergetics: From psychophysical isomorphism to holistic emergentism

Abstract Gestalt theory is discussed as one main precursor of synergetics, one of the most elaborated theories of self‐organization. It is a precursor for two reasons: the Gestalt theoretical view of cognitive order‐formation comes dose to the central ideas of self‐organization. Furthermore both approaches have stressed the significance of non‐linear perceptual processes (such as multistability) for the solution of the mind‐brain problem. The question of whether Gestalt theory preferred a dualistic or a monistic view of the mind‐body relation is answered in that there was a preference for dualism in epistemological questions and for monism in the mind‐brain relation. The latter was attained by the concept of psychophysical isomorphism. This concept, although widely misunderstood in many respects, was criticized on the basis of neurobiological findings. One main objection was the neglect of the importance of the elementary neurophysiological processes. A distinction between macroscopic and microscopic brai...

Continuous phase transitions in the perception of multistable visual patterns

Abstract.The phenomenon of stroboscopic alternative motion exhibits five different percepts that are seen with an increase in the frequency of presentation: (a) succession, (b) fluttering motion, (c) reversible clockwise and counter-clockwise turning motion, (d) oppositional motion and (e) simultaneity. From a synergetic point of view the increase in frequency is a control parameter and the different percepts are order parameters with phase transitions in between. The neural network model of Carmesin and Arndt is applied to receive predictions about hysteresis and phase transitions between these order parameters. Empirical data show the different motion percepts (b), (c) and (e) have lognormal distributions. Following the theoretical model, it is argued that there are three different phases, (a), (c) and (e), with two continuous phase transitions, (b) and (d), between them. The experimental data substantially match the theoretical ssumptions.

The Significance of Perceptual Multistability for Research on Cognitive Self-Organization

Perceptual order formation is a process of self-organization in a complex neural network and not a pick up of external information. In this view any stimulus condition is multistable. Stimuli are only boundary conditions of the autonomous process of perceptual order formation. Stability in perception is the result of a fast converging process of autonomous order formation which normally acts on a time scale far beyond conscious realization. Multistability in perception is an exceptional case in which the process of order formation (confronted with one constant boundary condition) spontaneously oscillates between two or more attractors established in the system dynamics. The spontaneous reversions in perceptual multistability show characteristics of nonlinear phase transitions and can be simulated with a high degree of correspondence on basis of self-organizing networks and synergetic modelling. In everyday experience multistability in perception is a relatively irrelevant curiosity but for investigating the process of order formation in cognition multistability is a paradigmatical research tool. Perceptual multistability can be used as a window to the underlying neural system dynamics. In a variety of different experiments the possibility is shown to change the potential landscape of the system dynamics in multistable perception by learning, context and meaning. The reversion process is discussed as an indicator for innersystemic fluctuations. Some hypothetical links to pathological phenomena in cognition are outlined.

Cognitive Systems as Self-Organizing Systems

The theory of self-organization is beginning to penetrate into the entire spectrum of scientific disciplines. The initial ideas that led to self-organization theory can be traced back into the historical tradition of the social and natural sciences. The theory of self-organization in a narrower sense, however, is usually said to have begun with the works of Manfred Eigen, Heinz von Foerster, Ernst von Glasersfeld, Hermann Haken, Humberto Maturana and Ilja Prigogine.1 If one considers these works as the basis, two main conceptual points of reciprocal causal relationship may be distinguished: the emphasis on the purely theoretical, system-related aspect and the emphasis on the epistemological aspect of self-organization.

Der psychische Apparat des Menschen

Kein anderes Problem hat die Philosophiegeschichte nachhaltiger bestimmt als die Frage nach dem Verhaltnis von Sein und Bewustsein, nach der Moglichkeit oder Unmoglichkeit objektiver, „wahrer“ Erkenntnis. Die logische Konsequenz einer skeptischen Position steht in deutlichem Widerspruch zu unseren Alltagsuberzeugungen.