Visual recognition thresholds in a compressed air environment

An experiment was performed to determine the effects of different high-pressure air environments on human binocular visual recognition time as a function of stimulus size and type. Eight adult male volunteers were randomly exposed to high-pressure air environments in hyperbaric test chambers instrumented for visual studies. Analysis of variance for a three-factor repeated-measures design revealed significant main effects for the variables of stimulus size and pressure, indicating that recognition time (RT) increases as a function of decreasing stimulus size and increased pressure. A significant interaction was also observed between the independent variables of pressure and stimulus type with stimulus type having the greatest effect at low pressure. These results are discussed for their applicability to the design of underwater equipment, visual displays, and the occupational safety of underwater workers.