 |
|
JCS, 3 ( 5-6) 1996 , pp. 492-499
Craig DeLancey, Department of Philosophy, Department of Cognitive Science, Indiana University, Bloomington, USA. Email: cdelance@phil.indiana.edu
Certain arguments that phenomenal conscious states play no role, or play a role that could be different, depend upon the seeming plausibility of thought experiments such as the inverted spectrum or phenomenal zombie. These thought experiments are always run for perceptual states like colour vision. Run for affective states like emotions, they become absurd, because the prior intension of our concepts of emotional states are that the phenomenal experience is inseparable from their motivational aspects. Our growing scientific understanding of emotion and motivation lends inductive evidence to this view. This points the way towards a positive hypothesis that affective consciousness is type-specific to its function.
JCS, 3 ( 5-6) 1996 , pp. 448-462
Michael T. Alkire, Richard J. Haier, James H. Fallon and Steven J. Barker,,
Department of Anesthesiology, University of California, Irvine Medical
Center, Route 81A, Bldg 53, 101 City Drive South, Orange, CA 92668, USA.
Email: MAlkire@UCI.EDU
One method for investigating the neurobiology of consciousness is to experimentally manipulate consciousness as a variable and then visualize the resultant functional brain changes with advanced imaging techniques. To begin investigation into this area, healthy volunteers underwent positron emission tomography scanning while listening to randomized word lists in both conscious and unconscious (i.e. anaesthetized) conditions. Following anaesthesia, subjects had no explicit memories. Nonetheless, subjects demonstrated implicit memory on a forced-choice test (different from chance; p <0.01). These subsequent memory scores were correlated with regional brain metabolism measured during encoding. Conscious recall and unconscious recognition memory demonstrated considerable anatomic overlap in correlating significantly with relative glucose metabolism in auditory verbal memory areas. However, only conscious recall correlated with mediodorsal thalamic nucleus activity; unconscious recognition memory did not. These findings suggest that conscious versus unconscious memory distinctions may depend on the presence or absence of correlated thalamic activity, and directly implicate the thalamus in the neurobiology of consciousness.
JCS, 3 ( 5-6) 1996 , pp. 425-447
N.G. de Bruijn, Department of Mathematics and Computing Science, Eindhoven University of Technology, PO Box 513, 5600MB Eindhoven, The Netherlands. Email: wsdwnb@win.tue.nl
The paper presents a speculative model for associative memory. It has two layers: the lower layer describes memory of a single cell, the upper layer describes how the work is distributed address-free over a large set of cells. Thinking, consciousness and various features of memory are interpreted in terms of the memory model.
JCS, 3 ( 5-6) 1996 , pp. 484-491
Alwyn C. Scott, Department of Mathematical Modelling, Technical University of Denmark, DK-2800 Lyngby, Denmark.
In response to recent suggestions that the phenomena of consciousness may be related to those described by quantum theory, it is argued that distinctive features of brain activity (global coherence, threshold affects, binding of cell assemblies, etc.) are more typical of nonlinear classical dynamics than of quantum dynamics, which is a linear theory. Thus natural scientists should turn to hierarchies of nonlinear classical systems rather than quantum theory for explanations of the brain’s mysterious behaviour.
JCS, 3 ( 5-6) 1996 , pp. 463-476
Teed Rockwell, 2419A Tenth Street, Berkeley, CA 94710, USA
Email: 74164.3703@compuserve.com
Both Dennett and his critics believe that the invalidity of the famed Stalinist-Orwellian distinction is a consequence of his multiple drafts model of consciousness (MDM). This is not so obvious, however, once we recognize that the question
‘how do you get experience out of meat?’ actually fragments into at least three different questions. How (out of meat) do we get: (1) a unified sense of self, (2) awareness and (3) mental phenomena? In the latter chapters of Consciousness Explained, Dennett shows how MDM has a radical and profound way of interrelating awareness and self . But the Stalinist-Orwellian distinction can be dissolved by analysing the nature of mental phenomena, without making any reference to awareness or self or the MDM. This is because The Stalinist-Orwellian distinction rests on much the same category mistake (confusing of parts with wholes) which Ryle pointed out in his Concept of Mind. Once we recognize that a theory of awareness is trying to do something different from a theory of mental phenomena, we can see why Dennett and his critics frequently talked past each other, and how we can resolve these controversies by incorporating something like Rosenthal’s theory of higher order thoughts into the MDM. (Something he has come very close to doing already in his discussions of the ‘hunt the thimble’ phenomenon.) This would require, however, that Dennett abandon his principle of first person operationalism, and recognize that it is possible for us to be mistaken about our own internal states.
JCS, 3 ( 5-6) 1996 , pp. 477-483
Chris Nunn, Barfad Beag, Ardfern, Argyll PA31 8QN, Scotland
Email: 106264.266@compuserve.com
Following a theme which increasingly interests people concerned with problems of sentience, this paper describes how consciousness might encode information. The idea that awareness is inseparable from Bose-Einstein condensation in the brain is identified as the most promising of the ‘quantum consciousness’ notions. It can be inferred from this idea that brain Bose condensates will have a geometrical structure, analagous to that of tapestries, which can encode information and to which knot theory can be applied.These notions are able to explain otherwise puzzling features of conscious information handling and a neuroanatomically testable prediction is derived from them. Finally it’s pointed out that they imply that any ‘strong’ panpsychist position is unnecessary.
JCS, 3 ( 5-6) 1996 , pp. 409-424
Bruce, MacLennan, Computer Science Department, University of Tennessee, Knoxville 37996, USA.
The ‘hard problem’ is hard because of the special epistemological status of consciousness, which does not, however, preclude its scientific investigation. Data from phenomenologically trained observers can be combined with neurological investigations to establish the relation between experience and neurodynamics. Although experience cannot be reduced to physical phenomena, parallel phenomenological and neurological analyses allow the structure of experience to be related to the structure of the brain. Such an analysis suggests a theoretical entity, an elementary unit of experience, the protophenomenon, which corresponds to an activity site (such as a synapse) in the brain. The structure of experience is determined by connections (e.g. dendrites) between these activity sites; the connections correspond to temporal patterns among the elementary units of experience, which can be expressed mathematically. This theoretical framework illuminates several issues, including degrees of consciousness, nonbiological consciousness, sensory inversions, unity of consciousness and the unconscious mind.
JCS, 3 ( 5-6) 1996 , pp. 402-408
Patricia Smith Churchland, Department of Philosophy, University of California at San Diego, La Jolla, CA 92093, USA
Beginning with Thomas Nagel, various philosophers have propsed setting conscious experience apart from all other problems of the mind as ‘the most difficult problem’. When critically examined, the basis for this proposal reveals itself to be unconvincing and counter-productive. Use of our current ignorance as a premise to determine what we can never discover is one common logical flaw. Use of ‘I-cannot-imagine’ arguments is a related flaw. When not much is known about a domain of phenomena, our inability to imagine a mechanism is a rather uninteresting psychological fact about us, not an interesting metaphysical fact about the world. Rather than worrying too much about the meta-problem of whether or not consciousness is uniquely hard, I propose we get on with the task of seeing how far we get when we address neurobiologically the problems of mental phenomena.
JCS, 3 ( 5-6) 1996 , pp. 386-401
Douglas, J. Bilodeau, Indiana University Cyclotron Facility, 2401 Milo
B. Sampson Lane, Bloomington, IN 47408, USA.
Email: bilodeau@iucf.indiana.edu
The ‘hard problem’ of the origin of phenomenal consciousness in a physical universe is aggravated by a simplistic and uncritical concept of the physical realm which still predominates in much discussion of the subject. David Chalmers is correct in claiming that phenomenal experience is logically independent of a physical description of the world, but his proposal for a ‘natural supervenience’ of experience on a physical substrate is misguided. His statements about machine consciousness and the role of information are especially compromised. A careful analysis of physical concepts indicates that the hard problem as originally proposed is insoluble but also fortunately based on misconceptions. Modern physics suggests a more sophisticated and richer ontology which will be essential for a deeper understanding of our rapidly growing knowledge of psychology and neuroscience.
JCS, 3 ( 5-6) 1996 , pp. 500-514
Mary Midgley, 1a, Collingwood Terrace, Newcastle-upon-Tyne NE2 2JP, UK.
‘Explanations’ are of various kinds. They vary with the needs that call for them. The current need to ‘explain consciousness’ expresses not only curiosity about its causes but a wider uncertainty about its place in the general scheme of things. For much of this century, naive dogmatic materialism suggested that consciousness is a trivial matter with effectively no place in the world. Yet the behaviourists’ attempt to ignore our experience altogether has not proved workable. Scientists are therefore now trying to give it reputable standing by squeezing it in at the margins either of neurobiology or of some branch of physics, in the hope that this will make it ‘scientific’.
Home
page
JCS
Home Page