There are three versions of the subsumptive unity thesis: the pairwise version, the general version, and the total version. There are correspondingly three versions of the logical unity thesis, holding either that there is logical unity among either any two states of a subject at a time, any set of states, or the complete set of states. Or more directly: Pairwise Logical Unity Thesis: Necessarily, for any two phenomenal states had by a subject at a time, the subject has a phenomenal state that entails both original states. General Logical Unity Thesis: Necessarily, for any set of phenomenal states of a subject at a time, the subject has a phenomenal state that entails each state in the set. Total Logical Unity Thesis: Necessarily, for any conscious subject at a time, the subject has a phenomenal state T such that for any phenomenal state A of the subject at that time, T entails A. As before, it is clear that the general thesis entails the pairwise thesis and the total thesis as special cases. The total thesis also entails the general thesis and the pairwise thesis, since a state that entails all phenomenal states of a subject will also entail any pair or any set of states. Arguably the pairwise thesis does not entail the other two theses, because of the formal possibility that there might be entailing states for any finite set of states, but not for infinite subsets. We can start by focusing on the total logical unity thesis, since this corresponds most closely to the total phenomenal unity thesis, which arguably captures the central intuition behind the unity of consciousness. Intuitively, we can think of T, the entailing state in the thesis, as the subject's total phenomenal state, capturing what it is like to be the subject at that time. If such a state exists, it will fulfill the requirement of the total logical unity thesis. One can also approach the matter in logical terms. Let us say that the conjunction of a set of states is a state C such that necessary, a subject is in C if and only the subject is in each of the states in that set. (Like entailment, conjunction is fundamentally a relation among state-types, and derivatively a relation among state-tokens. Note also that the conjunction of states is quite different from conjunction of the contents of states.) This identifies C at least up to mutual entailment. For present purposes, it is useful to assume that when two states A and B mutually entail each other (i.e. when necessarily, a subject is in A if and only if the subject is in B), then the two states are identical. If so, then C is identified uniquely. Nothing that follows rests essentially on this assumption; one could rephrase things in terms of equivalence classes of states.

Be first to comment this article | Quote this article on your site | Views: 520 | Print | E-mail

What is the general module of consciousness? What does it mean to say that different states of consciousness are unified with each other, or that they are part of a single encompassing state? The idea of unity is multifaceted, and has been understood in many different ways by different thinkers. In some senses of "unity", the claim that consciousness is unified may be

obvious or trivial; in other senses, the claim may be obviously false. So the first project in this area is to distinguish between varieties of unity, and to isolate those varieties that pose the most important questions. Is consciousness necessarily unified? Some thinkers (Descartes and Kant,

Be first to comment this article | Quote this article on your site | Views: 573 | Print | E-mail

In what sense, then, is the mind unlike a computer? Some scientists thinks the answer might have something to do with quantum physics. A system at the quantum level (a group of hydrogen atoms, for instance) does not have a single course of behavior, or state, but a number of different possible states that are somehow "superposed" on one another. When a physicist measures the system, however, all the superposed states collapse into a single state; only one of all the possibilities seems to have occurred. Roger Penrose finds this apparent dependence of quantum physics on human observation-as well as its incompatibility with macroscopic events-profoundly unsatisfying. If the quantum view of reality is absolutely true, he suggests, we should see not a single cricket ball resting on a lawn but a blur of many balls on many lawns. He proposes that a force now conspicuously absent in quantum physics-namely gravity-may link the quantum realm to the classical, deterministic world we humans inhabit. But Penrose takes a new approach. He notes that as the various superposed states of a quantum-level system evolve over time, the distribution of matter and energy within them begins to diverge. At some level-intermediate between the quantum and classical realms-the differences between the superposed states become gravitationally significant; the states then collapse into the single state that physicists can measure. Seen this way, it is the gravitational influence of the measuring apparatus-and not the abstract presence of an observer that causes the superposed states to collapse. Quantum gravity can also help account for what are known as non-local effects, in which events in one region affect events in another simultaneously. The famous Einstein-Podolsky-Rosen thought experiment first indicated how nonlocality could occur: if a decaying particle simultaneously emits two photons in opposite directions, then measuring the spin of one photon instantaneously 'fixes" the spin of the other, even if it is light-years away. Penrose thinks quasicrystals may involve nonlocal effects as well. Ordinary crystals, he explains, grow serially, one atom at a time, but the complexity of quasicrystals suggests a more global phenomenon: each atom seems to sense what a number of other atoms are doing as they fall into place in concert. This process resembles that required for laying down Penrose tiles; the proper placement of one tile often depends on the positioning of other tiles that are several tiles removed.

Be first to comment this article | Quote this article on your site | Views: 616 | Print | E-mail

Be first to comment this article | Quote this article on your site | Views: 758 | Print | E-mail

1. Introduction

1.1 The current upsurge of intense interest in quantum brain theory and consciousness  fueled in large part by what Stapp calls "the fundamentally holistic character of the quantum mechanical description [of] nature [which is] perhaps its most basic and pervasive feature" (3.12). Since consciousness, too, in some difficult to define sense is holistic in character, the hope has arisen that consciousness can finally be explained in quantum terms. Classical mechanics, on the other hand, does not naturally accommodate consciousness, as Stapp nicely shows. His theory of consciousness is problematically founded, however, which vitiates the impact of his article.

 The Brain as Measuring Device

 Lets consider Stapp's view that the brain is, at a certain level selected in evolution, a quantum measuring device where Heisenberg actual events are conscious events.  The brain is, in effect, treated as a Heisenberg-type quantum measuring device.  The mental life of each human being is representable as a sub-sequence of the full sequence of Heisenberg events." The neural wave function enfolds superposed possibilities, and then consciousness chooses one classical branch and annihilates the others. The choice is "unruly," says, "not individually controlled by any known law of physics." So the heart of consciousness is random on Stapp's view. He hopes that some future physics will find a law, but it certainly looks like barring an enormous revolution in quantum physics, Stapp has installed chance deep in his theoretical framework, where the quantum choices associated with conscious events take place:

The question arises: What determines which of the alternative possible brain activities is actualized by an actual event? According to contemporary quantum theory, two factors contribute to that quantum choice. The first is the local deterministic evolution of tendencies governed by the Heisenberg equation of motion...Then an actual event occurs. This event actualizes one of the distinct top-level patterns of brain activity, and hence selects one of these distinct possible course of action. This selection is, according to contemporary quantum theory, made by the second factor: #pure chance#.

Be first to comment this article | Quote this article on your site | Views: 724 | Print | E-mail

Be first to comment this article | Quote this article on your site | Views: 758 | Print | E-mail

An approach to the mind-body problem based on physical laws has been advocated by several thinkers. Quantum Theory has been particularly intriguing for scientists eager to provide a physical explanation of consciousness.

Loosely speaking, the point is that consciousness is unlikely to arise from classical properties of matter (the more we understand the structure and the fabric of the brain, the less we understand how consciousness can occur at all), which are well known and well testable. But Quantum Theory allows for a new concept of matter altogether, which may well leave cracks for consciousness, for something that is not purely material or purely extra-material. Of course, the danger in this way of thinking is to relate consciousness and Quantum only because they are both poorly understood: what they certainly have in common is a degree of "magic" that makes both mysterious and unattainable...

On the other hand, it is certainly true that all current neurobiological descriptions of the brain are based on Newton's Physics, even if it is well known that Newton's Physics has its limitations. First of all, Newton's Physics is an offshoot of Descartes division of the universe in matter and spirit, and it deals only with matter. Secondly, neurobiologists assume that the brain and its parts behave like classical objects, and that quantum effects are negligible, even while the "objects" they are studying get smaller and smaller. What neurobiologists are doing when they study the microstructure of the brain from a Newtonian perspective is equivalent to organizing a trip to the Moon on the basis of Aristotle's Physics, neglecting Newton's theory of gravitation. 

No wonder most neurobiologists reach the conclusion that Physics cannot explain consciousness, since they are using a Physics that 1. was designed to study matter and leave out consciousness and that 2. does not work in the microworld. Not surprisingly, it has been claimed that all current neurobiological models are computationally equivalent to a Turing machine.

Be first to comment this article | Quote this article on your site | Views: 753 | Print | E-mail

 Neuroscience has the potential to improve our ways of teaching and learning, but that this potential can only be realized by 'humanizing' the highly technical language of brain science. For example, through neuroscience, we are beginning to understand why many of our students perform poorly on exams when we are fairly certain that they 'know' the material. Findings from neuroscience indicate that this results from our students 'downshifting' as their brain physiology responds to stress. That is, under the stress of test-taking, their cerebrum, the most advanced part of their brain, is slowed in the formation of neural networks while their less-advanced brainstem becomes dominant. This is a very effective explanation of the physiological dimension of our learners. What remains is to translate this explanation into a format useful for classroom teachers.

Neuroscience does not help us understand the human factors that determine why some students interpret a test as threatening (and therefore 'downshift'), while others interpret the same testing environment as challenging (and are able to excel). Although physiological explanations from neuroscience help us understand the mechanisms of the brain, they fall short of explaining the socio-cultural and phenomenological factors which initiate a stressful versus challenging interpretation of experience. Thus, dehumanized explanations of neuroscience findings seem less than useful to classroom teachers and similarly remain outside the understanding of most people.

Be first to comment this article | Quote this article on your site | Views: 704 | Print | E-mail