Changes in Risky Behavior in Long-Term Head-Down Bed Rest and Relation to Psychological Status

Area of Science:

• Human physiology and psychology
• Spaceflight analog research
• Risk assessment and behavior

Background:

• Investigating behavioral changes during simulated microgravity is crucial for astronaut health.
• Understanding psychological influences on risk-taking is vital for mission success.

Purpose of the Study:

• To examine changes in risky behavior during 90-day head-down bed rest (HDBR).
• To assess the influence of psychological factors (self-efficacy, stress, recovery) on these behavioral changes.

Main Methods:

• 36 healthy men underwent a 90-day HDBR protocol (-6° head-down tilt).
• Risk-taking behavior was measured using the Balloon Analog Risk Task (BART).
• Psychological status was assessed using general self-efficacy, stress, and recovery scales.

Main Results:

• Head-down bed rest significantly increased risk-taking behavior.
• Risk-taking propensity remained elevated post-bed rest, not returning to baseline.
• Higher stress levels correlated positively with risky behavior, while self-efficacy and recovery correlated negatively.
• Physical stress indicators (fatigue, somatic complaints, sleep quality) showed the strongest correlation with risk-taking.

Conclusions:

• Prolonged simulated microgravity and isolation sustain altered risk-taking tendencies.
• Changes in risky behavior during HDBR are strongly linked to physiological stress symptoms.
• These findings have implications for astronaut selection and psychological support during long-duration space missions.