Abstract
[Purpose] To examine autonomic nerve responses during a psychological stress task and subsequent breathing. [Subjects and Methods] Slow and normal breaths were measured randomly at more than two days apart. The Uchida-Kraepelin test was executed for 15 minutes as a psychological stress task after a 5-minute rest sitting on a chair. Subsequently, slow breathing or normal breathing was carried out for 5 minutes. Salivary alpha-amylase and heart rate variability were analyzed as autonomic nerve responses. [Results] Salivary alpha-amylase increased with stress, and decreased with slow breathing. The HF and LF/HF ratio were synchronized with neither stress nor slow breathing. [Conclusion] The findings of our study suggest that salivary alpha-amylase is a more sensitive test of psychological stress than heart rate variability.
