The effects of hypoxia on components of the human event-related potential and relationship to reaction time.

This experiment investigated the relationship between the increase in reaction time (RT) caused by hypoxia and the P300, N200, P200 and N100 components of the event-related brain potential. Eight subjects breathed air or a low oxygen mixture (65% arterial oxyhemoglobin saturation) and RT was collected to visually presented stimuli at two levels of stimulus intensity while ERPs were recorded. An hypoxia x stimulus intensity interaction was found for RT, P300 latency and N200 latency. P200 latency and N100 latency were unaffected by hypoxia. These results were interpreted in terms of Additive Factors Method logic to indicate that the preprocessing stage of stimulus evaluation is slowed by hypoxia and that both P300 and N200 index this slowing.