Online research in philosophy

In the beginning: introduction -- This I believe: preview -- This they believe: other views -- Where it begins: anatomy and environment -- Where it began: evolution -- What is it?: consciousness -- There was the word: self-consciousness and language -- See here: attention -- Perhaps to dream: sleep -- x=2y: representation -- The dance of life: movement -- They all fall down: dissolution of function -- Been there, done that: experience -- Which have eyes and see not: stimulus hierarchy -- Buy one, get one free: volition -- Play it again: speculative reprise -- In the end: conclusion.

One oft the most fascinating abilities of humans is the ability to become conscious of the own physical and mental states. In this systematic investigation of self-consciousness, a representational theory is developed that is able to distinguish between different levels of self-consciousness. The most basic levels are already present in such simple animals as ants. From these basic forms, which are also relevant for adult human self-consciousness, high-level self-consciousness including self-knowledge can arise. Thereby, the theory is not only able to integrate developmental considerations but also to sharply distinguish different aspects of the complex phenomenon self-consciousness. Pathological breakdowns of these different aspects, as they can be found in schizophrenia, are explained by specific impairments on different levels of self-representation. In this way, the work shows that a naturalistic theory of self-consciousness is possible, if the analysis starts with very simple and basic mechanisms instead of starting on the »top of the iceberg«.

An example is presented of a model of consciousness based on a description of the world which integrates the material and psychological aspects from the start. An indication is given of work under way to test the model.

In The Nature of Consciousness, Mark Rowlands develops an innovative and radical account of the nature of phenomenal consciousness, one that has significant consequences for attempts to find a place for it in the natural order. The most significant feature of consciousness is its dual nature: consciousness can be both the directing of awareness and that upon which awareness is directed. Rowlands offers a clear and philosophically insightful discussion of the main positions in this fast-moving debate, and argues that the phenomenal aspects of conscious experience are aspects that exist only in the directing of experience towards non-phenomenal objects, a theory that undermines reductive attempts to explain consciousness in terms of what is not conscious. His book will be of interest to a wide range of readers in the philosophy of mind and language, psychology, and cognitive science.

The significance of consciousness in modern science is discussed by leading authorities from a variety of disciplines. Presenting a wide-ranging survey of current thinking on this important topic, the contributors address such issues as the status of different aspects of consciousness; the criteria for using the concept of consciousness and identifying instances of it; the basis of consciousness in functional brain organization; the relationship between different levels of theoretical discourse; and the functions of consciousness.

The role of brain monoamines may be important for the neurobiology of the alterations of visual alertness in recurrent complex visual hallucinations (RCVH). This is evidenced by sleep research, neurophysiologic, and clinical data. Hence, the mechanisms of RCVH may not be simply explained by acetylcholine underactivity only.

In this article first some general aspects of near-death experience will be discussed, followed by questions about consciousness and its relation to brain function. Details will be described from our prospective study on near-death experience in survivors of cardiac arrest in the Netherlands, which was published in the Lancet in 2001. In this study it could not be shown that physiological, psychological, or pharmacological factors caused these experiences after cardiac arrest. Neurophysiology in cardiac arrest and in a normal functioning brain will be explained. Finally, implications for consciousness studies will be discussed, and how it could be possible to explain the continuity of our consciousness. Scientific study of NDE pushes us to the limits of our medical and neurophysiologic ideas about the range of human consciousness and mind-brain relation.

A unifying theory of general anesthetic-induced unconsciousness must explain the common mechanism through which various anesthetic agents produce unconsciousness. Functional-brain-imaging data obtained from 11 volunteers during general anesthesia showed specific suppression of regional thalamic and midbrain reticular formation activity across two different commonly used volatile agents. These findings are discussed in relation to findings from sleep neurophysiology and the implications of this work for consciousness research. It is hypothesized that the essential common neurophysiologic mechanism underlying anesthetic-induced unconsciousness is, as with sleep-induced unconsciousness, a hyperpolarization block of thalamocortical neurons. A model of anesthetic-induced unconsciousness is introduced to explain how the plethora of effects anesthetics have on cellular functioning ultimately all converge on a single neuroanatomic/neurophysiologic system, thus providing for a unitary physiologic theory of narcosis related to consciousness.