Introductory survey -- Atomic theory and mechanics -- The quantum postulate and the recent development of atomic theory -- The quantum of action and the description of nature -- The atomic theory and the fundamental principles underlying the description of nature.

It is widely accepted that consciousness or, more generally, mental activity is in some way correlated to the behavior of the material brain. Since quantum theory is the most fundamental theory of matter that is currently available, it is a legitimate question to ask whether quantum theory can help us to understand consciousness. Several approaches answering this question affirmatively, proposed in recent decades, will be surveyed. It will be pointed out that they make different epistemological assumptions, refer to different neurophysiological (...) levels of description, and use quantum theory in different ways. For each of the approaches discussed, problematic and promising features will be equally highlighted. (shrink)

Mainstream cognitive neuroscience typically ignores the role of quantum physical effects in the neural processes underlying cogni¬tion and consciousness. However, many unsolved problems remain, suggesting the need to consider new approaches. We propose that quantum theory, especially through an ontological interpretation due to Bohm and Hiley, provides a fruitful framework for addressing the neural correlates of cognition and consciousness. In particular, the ontological interpretation suggests that a novel type of 'active information', connected with a novel type of 'quantum potential energy', (...) plays a key role in quantum physical processes. After introducing the ontological interpretation we illustrate its value for cognitive neuroscience by discussing it in the light of a proposal by Beck and Eccles about how quantum tunneling could play a role in controlling the frequency of synaptic exocytosis. In this proposal, quantum tunneling would enable the 'self' to control its brain without violating the energy conservation law. We argue that the ontological interpretation provides a sharper picture of what actually could be taking place in quantum tunneling in general and in synaptic exocytosis in particular. Based on the notions of active information and quantum potential energy, we propose a coherent way of understanding how mental processes (understood as involving non-classical physical processes) can act on traditional, classically describable neural processes without violating the energy conservation law. (shrink)

We propose a distinction between precategorial, acategorial and categorial states within a scientifically oriented understanding of mental processes. This distinction can be specified by approaches developed in cognitive neuroscience and the analytical philosophy of mind. On the basis of a representational theory of mental processes, acategoriality refers to a form of knowledge that presumes fully developed categorial mental representations, yet refers to nonconceptual experiences in mental states beyond categorial states. It relies on a simultaneous experience of potential individual representations and (...) their actual “representational ground”, an undifferentiated precategorial state. This simultaneity is possible if the mental state does not reside in a representation but in between representations. Acategoriality can be formally modeled as an unstable state of a dynamical mental system that is subject to particular stability criteria. (shrink)