Fig. 2From: Exposure to blue light during lunch break: effects on autonomic arousal and behavioral alertnessDifferences between blue and orange lights in heart rate and heart rate variability (HRV) indices during light exposure (LitEx) and psychomotor vigilance test (PVT) after exposure in individual subjects (n = 8). Blu blue light, HF high-frequency component, LF low-frequency component, LF/HF LF-to-HF ratio in power, Org orange lightBack to article page