Effects of 0.65 MPa helium - oxygen exposure on memory and spatial reasoning of divers

Abstract

Objective To observe changes in the memory and spatial reasoning of divers under a pressure of 0.65 MPa and to further investigate effects of hyperbaric exposure on the psychological performance of divers. Methods Seven divers were tested for their memory and spatial reasoning with the spatial memory span test and spatial reasoning test before and during exposure to 0. 65 MPa helium-oxygen mixture. The memory and spatial reasoning indices obtained were used to compare different results between the two conditions. Results The results obtained from the two tests indicated that memory and spatial reasoning indices of the 6 divers (with only one exception) were influenced by 0.65 MPa exposure, and statistical difference could be seen between pre-exposure and post-exposure (P < 0. 05). Spatial reasoning test showed that there were obvious individual differences in divers. The score obtained under 0.65 MPa exposure was generally lower than that under normal pressure. Conclusions The memory and spatial reasoning of divers under helium-oxygen hyperbaric exposure dropped to some extent, whose mechanism remained to be explored. Key words: Diver; Heliox saturation; Memory; Spatial reasoning; Mental rotation