Endocrine reactions and cognitive performance at 60 metres hyperbaric pressure

Endocrine reactions and cognitive performance were examined in a dive to 60 metres hyperbaric pressure ( N = 29). There was a significant increase for prolactine and growth hormone, and a significant decrease for epinephrine and testosterone. Memory was significantly reduced at 60 metres. The factor pattern of the endocrine postdive measures showed a cortisol, a catecholamine, and a testosterone factor similar to previous stress-studies at 1 atmosphere. Confirming previous studies there was a correlation between perceptual defense reactions as tested by the Defense Mechanism (DMT) and cortisol. DMT also correlated with performance on a reasoning test when learning was controlled. Furthermore, for the postdive samples there was a correlation between cortisol and performance on the arithmetic test, while prolactine correlated to memory reduction. These results indicate that the endocrine reactions and the reduction in cognitive performance is due to an effect of the emotional reaction to the dive situation in addition to direct effects of the nitrogen narcosis.