Effects of hyperbaric environment on the P300 component of event-related potentials

Hyperbaric chamber dives at 19 ATA with helium-oxygen were performed at the Japan Marine Science Technology Center, Yokosuka, from January 31 to February 2 in 1990. During simulated underwater experiments, event-related potentials were recorded in 2 divers for assessment of the cognitive function. Although the P300 amplitude of the potentials did not show any significant change, its latency was clearly prolongated and this prolongation continued to when the decompression reached to 70 m below sea level. These findings indicated that the hyperbaric environment corresponding to 180 m below sea level or less must cause some cognitive dysfunctions and that P300 is useful for early detection of those dysfunctions or HPNS.