Alterations of source and connectivity EEG patterns under simulated deep-SEA condition

New wireless technologies can overcome technical and safety problems of older ones for recording biological signals in hyperbaric chamber. In an application of a Bluetooth system, we measured the electroencephalographic (EEG) activity in professional divers in a hyperbaric chamber to determine how oxygen affects the brain activity. The cortical sources and the connectivity of the EEG rhythms were estimated in three conditions: breathing air at sea level; breathing O₂ at a simulated depth of 18 msw; breathing air at sea level after decompression. The oxygen condition was characterized by an amplitude increase in the alpha and beta sources in the parietal and occipital areas and decrease in the occipital delta and theta sources for at least 20 mins, with a parallel disconnection of the frontal-parietal links in the early minutes of O₂ breathing. These results may be relevant for establishing a reference point in future studies on oxygen-sensitive subjects.