Contingent negative variation and evoked potential amplitude as a function of inspired nitrous oxide concentration.
P Fenwick, J Bushman, R Howard, I Perry, T Gamble
Electroencephalography and Clinical Neurophysiology October 1979 DOI: 10.1016/0013-4694(79)90163-9 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Sample size | 9 |
| Population | Nine human subjects inhaling nitrous oxide in oxygen |
| Intervention | Nitrous oxide |
| Dose | 10%, 20%, 30% and 40% nitrous oxide in oxygen |
| Measures | CNV (contingent negative variation), cortical evoked potential, reaction time |
| Key findings | Cortical evoked potentials decreased rapidly with increasing nitrous oxide concentrations, confirming earlier work by Lader and Morris (1974). Contrary to prediction, the contingent negative variation remained surprisingly well preserved up to the borders of unconsciousness, and CNV amplitude showed little correlation with attention, arousal or reaction time. |
Abstract
Nine subjects were given to breath 10%, 20%, 30% and 40% nitrous oxide in oxygen. The inhaled gas concentrations were monitored by a mass spectrograph. At each gas concentration the CNV was measured in a standard long S1-S2 CNV paradigm to a click and tone with a mandatory button press at S2. The results confirmed the previous observations of Lader and Morris (1974) that the cortical evoked potential decreases rapidly with increasing concentrations of nitrous oxide. The CNV, however, against prediction remains surprisingly well preserved up to the borders of unconsciousness. In this situation there is little correlation between CNV amplitude and attention, arousal or reaction time.