Volume 1, Issue 1, 2003

Chaotic Neuron Dynamics, Synchronization and Feature Binding: Quantum Aspects (pdf)
F. Tito Arecchi, Department of Physics, University of Firenze, Italy

A central issue of cognitive neuroscience is to understand how a large collection of coupled neurons combines external signals with internal memories into new coherent patterns of meaning. An external stimulus localized at some input spreads over a large assembly of coupled neurons, building up a collective state univocally corresponding to the stimulus. Thus, the synchronization of spike trains of many individual neurons is the basis of a coherent perception. Based on recent investigations of homoclinic chaotic systems and their synchronization, a novel conjecture for the dynamics of single neurons and, consequently, for neuron assemblies is formulated. Homoclinic chaos is proposed as a suitable way to code information in time by trains of equal spikes occurring at apparently erratic times. In order to classify the set of different perceptions, the percept space can be given a metric structure by introducing a distance measure between distinct percepts. The distance in percept space is conjugate to the duration of the perception in the sense that an uncertainty relation in percept space is associated with time-limited perceptions. This coding of different percepts by synchronized spike trains entails fundamental quantum features which are not restricted to microscopic phenomena. It is conjectured that they are related to the details of the perceptual chain rather than depending on Planck's action.


Does Consciousness Collapse the Wave-Packet? (pdf)
Dick J. Bierman, Department of Psychology, University of Amsterdam, The Netherlands

The "subjective reduction" interpretation of measurement in quantum physics proposes that the collapse of the wave-packet, associated with measurement, is due to the consciousness of human observers. A refined conceptual replication of an earlier experiment, designed and carried out to test this interpretation in the 1970s, is reported. Two improvements are introduced. First, the delay between pre-observation and final observation of the same quantum event is increased from a few microseconds in the original experiment to one second in this replication. Second, rather than using the final observers' verbal response as the dependent variable, his early brain responses as measured by EEG are used. These early responses cover a period during which an observer is not yet conscious of an observed event. Our results support the "subjective reduction" hypothesis insofar as significant differences in the brain responses of the final observer are found, depending on whether or not the pre-observer has been looking at the quantum event (exact binomial p < 0.02). Alternative "normal" explanations are discussed and rejected. It is concluded that the present results do justify further research along these lines.


Quantum Noise, Entanglement and Chaos the Quantum Field Theory of Mind/Brain States (pdf)
Eliano Pessa, Department of Psychology, University of Pavia, Italy and Giuseppe Vitiello, Department of Physics, University of Salerno, Italy

We review the dissipative quantum model of the brain and present recent developments related to the role of entanglement, quantum noise and chaos in the model.


Time-Entanglement Between Mind and Matter (pdf)
Hans Primas, Laboratorium für Physikalische Chemie, ETH Zürich, Switzerland

This contribution explores Wolfgang Pauli's idea that mind and matter are complementary aspects of the same reality. We adopt the working hypothesis that there is an undivided timeless primordial reality (the primordial "one world''). Breaking its symmetry, we obtain a contextual description of the holistic reality in terms of two categorically different domains, one tensed and the other tenseless. The tensed domain includes, in addition to tensed time, nonmaterial processes and mental events. The tenseless domain refers to matter and physical energy. This concept implies that mind cannot be reduced to matter, and that matter cannot be reduced to mind. The non-Boolean logical framework of modern quantum theory is general enough to implement this idea. Time is not taken to be an a priori concept, but an archetypal acausal order is assumed which can be represented by a one-parameter group of automorphisms, generating a time operator which parametrizes all processes, whether material or nonmaterial. The time-reversal symmetry is broken in the nonmaterial domain, resulting in a universal direction of time for the material domain as well.

Last revision: 8 January 2004