Anesthesia, neural information processing, and consciousness awareness

Consciousness and Cognition 9 (3):387-395 (2000)
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.
Keywords *Consciousness States  *General Anesthetics  *Neurons  *Reticular Formation  *Thalamus  Neuroanatomy  Neurophysiology
Categories (categorize this paper)
DOI 10.1006/ccog.1999.0420
 Save to my reading list
Follow the author(s)
Edit this record
My bibliography
Export citation
Find it on Scholar
Mark as duplicate
Request removal from index
Revision history
Download options
Our Archive

Upload a copy of this paper     Check publisher's policy     Papers currently archived: 30,370
External links

Setup an account with your affiliations in order to access resources via your University's proxy server
Configure custom proxy (use this if your affiliation does not provide a proxy)
Through your library
References found in this work BETA

View all 10 references / Add more references

Citations of this work BETA
Anesthesia-a Descent or a Jump Into the Depths?R. A. Veselis - 2001 - Consciousness and Cognition 10 (2):230-235.

Add more citations

Similar books and articles
Neural Darwinism and Consciousness.Anil K. Seth & Bernard J. Baars - 2005 - Consciousness and Cognition 14 (1):140-168.
Why the Neural Correlates of Consciousness Cannot Be Found.Bernard Molyneux - 2010 - Journal of Consciousness Studies 17 (9-10):168-188.
Added to PP index

Total downloads
29 ( #181,739 of 2,193,768 )

Recent downloads (6 months)
1 ( #290,980 of 2,193,768 )

How can I increase my downloads?

Monthly downloads
My notes
Sign in to use this feature