Consciousness and Anesthesia

By M. Alkire, A. Hudetz, Giulio Tononi. Science, 2008

1,208 citations recorded by the source corpus.

When we are anesthetized, we expect consciousness to vanish. But does it always? Although anesthesia undoubtedly induces unresponsiveness and amnesia, the extent to which it causes unconsciousness is harder to establish. For instance, certain anesthetics act on areas of the brain's cortex near the midline and abolish behavioral responsiveness, but not necessarily consciousness. Unconsciousness is likely to ensue when a complex of brain regions in the posterior parietal area is inactivated. Consciousness vanishes when anesthetics produce functional disconnection in this posterior complex, interrupting cortical communication and causing a loss of integration; or when they lead to bistable, stereotypic responses, causing a loss of information capacity. Thus, anesthetics seem to cause unconsciousness when they block the brain's ability to integrate information.

Subfields: Anesthesiology and Pain Medicine, Developmental Neuroscience, Psychiatry and Mental health

View Paper: https://www.semanticscholar.org/paper/b3cf089a45f03703ad1ba33872866f40006912e3

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Anesthesiology and Pain Medicine

1. Giulio Tononi

In Developmental Neuroscience

1. Giulio Tononi

In Psychiatry and Mental health

1. Olaf Sporns
2. Quentin Noirhomme
3. Giulio Tononi
4. Audrey Vanhaudenhuyse
5. Melanie Boly
6. Steven Laureys
7. Michael D. Greicius
8. E. Bullmore

Citations in the corpus

• Beta-band oscillations--signalling the status quo? (2010, neutral): “States of low arousal, such as deep sleep or anaesthesia, in contrast, are characterized by spatially less specific, global synchronization of slow oscillations [13,15].”
• Signature of consciousness in the dynamics of resting-state brain activity (2015, background): “According to these theories, the functional networks that support consciousness must display both global integration—evidenced as a strong coupling between long-distance brain regions—and a large repertoire of heterogeneous functional states of activity (44).”
• Consciousness as Integrated Information: a Provisional Manifesto (2008, result): “Similar changes are seen in animal studies of anesthesia (Alkire et al., 2008).”
• A Theoretically Based Index of Consciousness Independent of Sensory Processing and Behavior (2013, background): “This aspect is relevant because hypersynchronous or widespread cortical activations can be observed when consciousness is lost during anesthesia (1, 41), NREM sleep (21, 42), and generalized seizures (43, 44).”
• Complex brain networks: graph theoretical analysis of structural and functional systems (2009, background): “…is involved in self-referential processing, imagery and memory 61 , and its deactivation is associated with anaes-thetic-induced loss of consciousness 62 . an intriguing hypothesis suggests that these functional aspects can be explained on the basis of its high centrality in the cortical network.”
• Breakdown of within- and between-network Resting State Functional Magnetic Resonance Imaging Connectivity during Propofol-induced Loss of Consciousness (2010, background): “The role of thalamocortical connectivity in anesthesia-induced loss of consciousness is widely discussed in neuroscience literature.(9,14,62) We show that decreased thalamocortical connectivity in default network and bilateral executive-control networks correlates with propofol-induced decrease of c”
• Electroencephalogram signatures of loss and recovery of consciousness from propofol (2013, background): “These highly structured oscillations could provide a means to disrupt integrated information processing within the brain (56) as well as anterior–posterior cortical feedback (41, 57, 58), both of which are considered crucial for conscious processing (56, 59).”
• Experimental and theoretical approaches to conscious processing. (2011, background): “These data suggest that in humans, the early stage of anesthesia correlates with cortical disruption, and that the effects on the thalamus are indirectly driven by cortical feedback (Alkire et al., 2008).”
• Recovery of cortical effective connectivity and recovery of consciousness in vegetative patients (2012, neutral): “BRAIN”
• AVMA Guidelines for the euthanasia of animals (2013, positive): “Further, the abrupt loss of consciousness that occurs at a critical concentration of anesthetic implies that the integrated repertoire of neural states underlying consciousness may collapse nonlinearly.(44) Cross-species data suggest that memory and awareness are abolished with less than half the co”