Encoding and decoding of connected discourse during altered states of consciousness.
D. Edwards, J. A. Harris, R. Biersner
The Journal of Psychology 1976 DOI: 10.1080/00223980.1976.9921340 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 44 |
| Population | Male corpsmen in the U.S. Navy, ages 20-29 |
| Intervention | Nitrous oxide |
| Duration | 10-minute breathing period |
| Topics | Altered states of consciousness |
| Key findings | Nitrous oxide inhalation impairs verbal processing, with low semantic context causing the greatest performance deficits. |
Abstract
The following hypotheses were investigated in a study of memory recall and an altered state of consciousness: (a) A direct relationship was expected between the magnitude of correct responses and task complexity. (b) Semantic context variation was expected to cause greater impairment in verbal processing than variation in syntactic constraints. (c) Under N2O fewer correct responses in verbal processing were expected to be made. Forty-four volunteers, male corpsmen in the U. S. Navy between the ages of 20 and 29, were randomly divided into two equal groups: a nitrous oxide group and an air group. After breathing either N2O or air for 10 minutes, Ss were required to repeat pairs of taped sentences of high syntax/high semantic context to low syntax/low semantic context. Responses were scored for errors. All three hypotheses were accepted. Task complexity caused the greatest magnitude of errors. Ss were able to compensate for variations in syntax and in the gas state, but low semantic quality strongly affected performance. The factors interacted in powerful ways to produce differential response errors from a low error rate for air/high syntax/high context to a high error rate for N2O/low syntax/low context.
Comparable studies
Other randomized controlled trials on altered states of consciousness, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Changes in global and thalamic brain connectivity in LSD-induced altered states of consciousness are attributable to the 5-HT2A receptor Healthy human participants | 2018 | Double-blind, randomized, counterbalanced, cross-over study | n = 24 |
| Effective connectivity changes in LSD-induced altered states of consciousness in humans. Healthy participants | 2019 | Double-blind, randomized, placebo-controlled, cross-over study | n = 25 |
| Dose-related effects of salvinorin A in humans: dissociative, hallucinogenic, and memory effects. Healthy hallucinogen-using adults | 2013 | Double-blind, placebo-controlled study | n = 8 |
| High doses of dextromethorphan, an NMDA antagonist, produce effects similar to classic hallucinogens. Healthy volunteers with histories of hallucinogen use | 2012 | Randomized controlled trial | n = 12 |
| A placebo-controlled investigation of synaesthesia-like experiences under LSD. | 2016 | Within-groups placebo-controlled pilot study |