Progressive Deterioration in Short Term Memory while Breathing Pure Oxygen at Normal Atmospheric Pressure

Twelve men performed a step tracking task involving short term memory while breathing pure oxygen from a demand-type oxygen mask, while breathing air from the mask, and in a control condition without the mask. A reliable progressive deterioration over 8 minutes was found while breathing oxygen, but not in the other 2 conditions. The progressive deterioration was particularly marked in the most difficult short term memory condition. It suggests that men should not breathe 100 oxygen at normal atmospheric pressure for periods longer than a few minutes if they must remain fully efficient.