DISSOCIATION OF THE BEHAVIORAL AND SUBJECTIVE COMPONENTS OF NITROGEN NARCOSIS AND DIVER ADAPTATION

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Authors
  1. Hamilton, K.
  2. Laliberte, M-F.
  3. Fowler, B.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
We investigated adaptation to nitrogen narcosis by compressing 11 highly experienced divers in a hyperbaric chamber to the equivalent of 54.6 meters of seawater once a day for 5 consecutive days. The behavioral component of narcosis was assessed with a serial choice-reaction time (RT) task, and the subjective component with a global magnitude estimate. Supplementary magnitude estimates were obtained with adjectives describing work effectiveness and body sensations. The results showed that there was no adaptation on the RT task, although learning was evident. In contrast, the global estimate dissociated from RT and showed clear adaptation by Day 3. The work effectiveness adjectives followed RT and did not show adaptation. Some body sensation adjectives showed clear adaptation, but others did not. These results lead to the conclusion that the anecdotal reports of adaptation by divers can probably be attributed to the subjective rather than the behavioral component of narcosis. Dissociation of these components suggests mediation by different brain mechanisms, and it is speculated that the gamma-aminobutyric acid/benzodiazepine receptor complex, which has been implicated in both the anesthetic and anxiolytic properties of agents such as nitrous oxide, may be involved.
Keywords
Gamma-aminobutyric acid;Hyperbaric chambers;Anxiolytic properties;Subjective ratings
Report Number
DCIEM-95-61 — Reprint
Date of publication
30 Jul 1991
Number of Pages
9
Reprinted from
Undersea & Hyperbaric Medicine, vol 22, no 1, 1995, p 41-49
DSTKIM No
95-05072
CANDIS No
154358
Format(s):
Document Image stored on Optical Disk;Hardcopy

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