Off-campus access
Using PhilPapers from home?
Click here to configure this browser for off-campus access.
- Peter Cariani (2000). Anesthesia, Neural Information Processing, and Consciousness Awareness. Consciousness and Cognition 9 (3):387-395.Possible systemic effects of general anesthetic agents on neural information processing are discussed in the context of the thalamocortical suppression hypothesis presented by Drs. Alkire, Haier, and Fallon (this issue) in their PET study of the anesthetized state. Accounts of the neural requisites of consciousness fall into two broad categories. Neuronal-specificity theories postulate that activity in particular neural populations is sufficient for conscious awareness, while process-coherence theories postulate that particular organizations of neural activity are sufficient. Accounts of anesthetic narcosis, on the other hand, explain losses of consciousness in terms of neural signal-suppressions, transmission blocks, and the disruptions of signal interpretation. While signal-suppression may account for the actions of some anesthetic agents, the existence of anesthetics, such as choralose, that cause both loss of consciousness and elevated discharge rates, is problematic for a general theory of narcosis that is based purely on signal suppression and transmission-block. However, anesthetic agents also alter relative firing rates and temporal discharge patterns that may disrupt the coherence of neural signals and the functioning of the neural networks that interpret them. It is difficult at present, solely on the basis of regional brain metabolic rates, to test process-coherence hypotheses regarding organizational requisites for conscious awareness. While these pioneering PET studies have great merit as panoramic windows of mind-brain correlates, wider ranges of theory and empirical evidence need to be brought into the formulation of truly comprehensive theories of consciousness and anesthesia.Reading list | Discuss | Edit | Categorize |My bibliography
| Export citation | Other links: linkinghub.elsevier.com dx.doi.org | Scholar | At my library 
Similar books and articles
The search for neural correlates of consciousness (or NCCs) is arguably the cornerstone in the recent resurgence of the science of consciousness. The search poses many difficult empirical problems, but it seems to be tractable in principle, and some ingenious studies in recent years have led to considerable progress. A number of proposals have been put forward concerning the nature and location of neural correlates of consciousness. A few of these include.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Other links: consc.net u.arizona.edu cs.colorado.edu | Scholar | At my library | More options ...
| | Other links: consc.net u.arizona.edu cs.colorado.edu | Scholar | At my library | More options ... In "Brainshy: Non-neural theories of conscious experience," (this volume) Patricia Churchland considers three "non-neural" approaches to the puzzle of consciousness: 1) Chalmers' fundamental information, 2) Searle's "intrinsic" property of brain, and 3) Penrose-Hameroff quantum phenomena in microtubules. In rejecting these ideas, Churchland flies the flag of "neuralism." She claims that conscious experience will be totally and completely explained by the dynamical complexity of properties at the level of neurons and neural networks. As far as consciousness goes, neural network firing patterns triggered by axon-to-dendrite synaptic chemical transmissions are the fundamental correlates of consciousness. There is no need to look elsewhere.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the ‘dynamic core’). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Other links: nsi.edu vesicle.nsi.edu ncbi.nlm.nih.gov linkinghub.elsevier.com dx.doi.org | Scholar | At my library | More options ...
| | Other links: nsi.edu vesicle.nsi.edu ncbi.nlm.nih.gov linkinghub.elsevier.com dx.doi.org | Scholar | At my library | More options ... As far as an adequate understanding of phenomenal consciousness is concerned, representationalist theories of mind which are modelled on the information processing paradigm, are, as much as corresponding neurobiological or functionalist theories, confronted with a series of arguments based on inverted or absent qualia considerations. These considerations display the following pattern: assuming we had complete knowledge about the neural and functional states which subserve the occurrence of phenomenal consciousness, would it not still be conceivable that these neural states (or states with the same causal r.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Other links: uni-bielefeld.de | Scholar | At my library | More options ...
| | Other links: uni-bielefeld.de | Scholar | At my library | More options ... From the assumption that the presence of consciousness is detectable, in the first instance, only from behavioral indicators, I offer a proof to the effect that, with respect to any theory T that states that some particular state or process is the neural correlate of consciousness, there are always rival neural correlates that, from T’s perspective, can never be empirically ruled out. That's because, with respect to these states, the means of detecting consciousness is disrupted along with the empirical test. Possible responses are discussed.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... O'Regan & Noë (O&N) are pessimistic about the prospects for discovering the neural correlates of consciousness. They argue that there can be no one-to-one correspondence between awareness and patterns of neural activity in the brain, so a project attempting to identify the neural correlates of consciousness is doomed to failure. We believe that this degree of pessimism may be overstated; recent empirical data show some convergence in describing consistent patterns of neural activity associated with visual consciousness.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Scholar | At my library | More options ...
| | Scholar | At my library | More options ... 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.
Reading list
| Discuss | Edit | Categorize | My bibliography | Export citation | Other links: linkinghub.elsevier.com dx.doi.org | Scholar | At my library | More options ...
| | Other links: linkinghub.elsevier.com dx.doi.org | Scholar | At my library | More options ... Discussion of Peter Cariani, Anesthesia, neural information processing, and consciousness awareness
 Back
All discussions
Start a new thread
|
There are no threads in this forum |
Nothing in this forum yet.
