Human tracking performance changes during combined +Gz and +/- Gy stress

Area of Science:

• Human factors and performance under stress
• Aerospace medicine
• Physiological responses to G-force and radiation

Background:

• Understanding human performance limitations is crucial for aerospace safety.
• Previous research indicates G-force impacts cognitive and motor functions.
• The combined effects of G-force and radiation on performance are not fully understood.

Purpose of the Study:

• To evaluate roll-axis tracking performance under simulated aerospace stress conditions.
• To quantify performance decrements associated with +5 Gz and combined +5 Gz/+/- radiation exposure.
• To assess the adequacy of standard restraint systems in these environments.

Main Methods:

• Human subjects were exposed to static and dynamic stress environments on a centrifuge.
• Stress conditions included +5 Gz and combined +5 Gz with +/- 1 or +/- 2 Gray (Gy) radiation for 95 seconds.
• Roll-axis tracking performance and heart rate were monitored.

Main Results:

• Roll-axis tracking performance decreased by 19% at +5 Gz, 45% at +5 Gz/+/- 1 Gy, and 70% at +5 Gz/+/- 2 Gy compared to static conditions.
• Heart rate increased during stress conditions.
• No significant heart rate differences were observed between +5 Gz and +5 Gz/+/- 2 Gy conditions.

Conclusions:

• Combined +5 Gz and radiation exposure significantly impairs roll-axis tracking performance.
• Standard lap belt and shoulder harness restraint systems were adequate for the tested G environments.
• Further research may be needed to explore optimal restraint and protective measures for combined stressors.