Biomedical subjects

H Haken

Publications and source records attributed to H Haken.

6 recordsLinked to original sources

PubMed1990

The impact of fluctuations on the recognition of ambiguous patterns.

The recognition of ambiguous patterns by humans is modelled by coupled differential equations which describe the formation of percepts by means of order parameters which in turn are determined by the saturation of attention parameters. We study the impact of fluctuations on the attention parameters and thus indirectly on the recognition of ambiguous patterns. Excellent agreement with psychophysical experimental results by Price on the transient behaviour of switching times and by Borsellino et al. on the distribution function of switching times as function of the size of the visual field is obtained. Our model allows us to deal also with the shift of width and position of the distribution function with respect to slow and fast observers in the sense of Borsellino.

Humans↗

PubMed1988

Pattern recognition and associative memory as dynamical processes in a synergetic system. I. Translational invariance, selective attention, and decomposition of scenes.

We consider a model for associative memory and pattern recognition which was devised by Haken (1987b). This model treats the activity of the neurons as continuous variables and exploits an analogy with pattern formation in synergetic systems. The capability of such a system to act as associative memory is demonstrated by the reconstruction of faces which are partially offered to the system, and which are restored by the corresponding dynamical process. We demonstrate how this model can be cast into a form which is translation invariant and how partially hidden faces in scenes can be recognized by means of the control of attention parameters of specific patterns.

Cybernetics↗

PubMed1987

Information compression in biological systems.

In biological systems a high coordination between their individual parts occurs. The concept of coordination can be given a rigorous mathematical basis by the concept of order parameters and the slaving principle. We calculate the information of the total system in terms of order parameters and slaved subsystems. When qualitative changes of a system happen, the information change is given by that of the order parameters alone and may amount to few bits only.

Animals↗

PubMed1986

A stochastic theory of phase transitions in human hand movement.

The order parameter equation for the relative phase of correlated hand movements, derived in a previous paper by Haken et al. (1985), is extended to a time-dependent stochastic differential equation. Its solutions are determined close to stationary points and for the transition region. Remarkably good agreement between this theory and recent experiments done by Kelso and Scholz (1985) is found, and new predictions are offered.

Hand↗

PubMed1985

A theoretical model of phase transitions in human hand movements.

Earlier experimental studies by one of us (Kelso, 1981a, 1984) have shown that abrupt phase transitions occur in human hand movements under the influence of scalar changes in cycling frequency. Beyond a critical frequency the originally prepared out-of-phase, antisymmetric mode is replaced by a symmetrical, in-phase mode involving simultaneous activation of homologous muscle groups. Qualitatively, these phase transitions are analogous to gait shifts in animal locomotion as well as phenomena common to other physical and biological systems in which new "modes" or spatiotemporal patterns arise when the system is parametrically scaled beyond its equilibrium state (Haken, 1983). In this paper a theoretical model, using concepts central to the interdisciplinary field of synergetics and nonlinear oscillator theory, is developed, which reproduces (among other features) the dramatic change in coordinative pattern observed between the hands.

Hand↗

PubMed1971

[Quantum optics].

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History, 17th Century↗