AUDITORY EVENT-RELATED POTENTIALS AND REACTION-TIME DURING DECOMPRESSION FROM HYPERBARIC TRIMIX CONDITIONS

Background: Auditory event-related potentials (ERP) and sensomotor rea ction time (RT) were investigated in divers during decompression from hyperbaric trimix conditions in order to assess the auditory informati on processing of the divers. Methods: Two passive series, 30 low (800 Hz) and 30 high (1200 Hz) tones were presented as well as one simple r eaction task (SRT) and one choice reaction task (CRT) series. In both task series, the subjects were instructed to press the button as quick ly as possible with the right-hand thumb after a low tone was heard. T he individual analyses of the decompression period ERPs and RT data we re compared with the pre-diving results for the series. Results: Despi te the interindividual differences, the sensomotor reactions were reta rded during the decompression period, most clearly in the CRT. A prolo ngation of the N2 and P3 latency in this series gives grounds to accep t that a cognitive slowing takes part in the longer reaction times dur ing decompression. The slowing of the auditory information processing during decompression manifests with task manipulation difficulties.