ABSTRACT
Data are presented from human observers performing cognitive tasks under different levels of hypoxia equivalent to breathing air at altitudes ranging from 7,000 feet to 14,000 feet. Hypoxia was experimentally induced either by reducing the partial pressure of oxygen in a hypobaric chamber, or by requiring the subjects to breathe oxygen-deficient gas mixtures at sea level. Blood-oxygen saturation levels were continuously monitored using pulse oximetry. Normoxic control conditions were also conducted. Data, analysed using the theory of signal detection, show that hypoxia can selectively affect the two components of an observer’s decision-making behaviour - their sensory capability, and their preference (or, bias) for making one decision over another. It is concluded that the theory of signal detection makes a valuable contribution to the quantitative measurement of decision making in aviation environments.
