Department of Psychology, The Pennsylvania State University, University Park 16802, USA.
BACKGROUND: The purpose of this study was to see if slow deep breathing, a non-pharmacological procedure known to increase parasympathetic nervous system (PNS) activity, would prevent the development of gastric dysrhythmias and symptoms of motion sickness when subjects were exposed to a rotating optokinetic drum. METHODS: Participating in this study were 46 healthy males and females aged 17-26 who were pre-tested in the rotating drum and found to be susceptible to motion sickness. They were randomly placed into one of the following three conditions: Slow Deep Breathing (n = 18), Counting Breaths (subjects were asked to count their breaths and asked for the count every 3 min, n = 16), and Control (subjects breathed normally, n = 12). Electrogastrograms were recorded from all subjects during a 6-min baseline and a 16-min rotation period. Subjects were asked about their symptoms every 3 min. RESULTS: A significant difference in percent tachygastria from baseline to rotation was found between the three conditions. Percent tachygastria increased during rotation for the Counting Breaths group and the Control group, but remained the same as baseline for the Slow Deep Breathing group. The Slow Deep Breathing group (5.3) reported significantly fewer symptoms than the Counting Breaths group (9.0), but not the Control group (7.8). CONCLUSION: In conclusion, slow deep breathing in a situation previously demonstrated to provoke tachygastria prevented the development of gastric dysrhythmias and decreased symptoms of motion sickness.