Electrocardiogram recordings from eight healthy adults without prior meditation experience, collected as part of a larger randomized controlled trial, showed that an eight-week mindful-attention meditation intervention increased heart rate variability (HRV) and decreased the LF/HF ratio, indicating improved autonomic function and more predominant vagal tone. These changes were not seen in the control group. A marked increase in respiratory sinus arrhythmia (RSA) occurred during meditation compared to rest. The authors suggest RSA may be a useful marker of the meditative state and encourage further research on HRV measures as indicators of autonomic health after meditation.
Body odours from people in emotional states can influence others, a phenomenon known as emotional contagion. This pilot study tested whether adding emotional body odours to mindfulness meditation reduces anxiety more than mindfulness alone. Ninety-eight women with Social Anxiety Disorder attended two mindfulness sessions while exposed to fear, joy, neutral body odour, or clean air. The primary hypothesis was not supported: there was no significant interaction between odour type and time on anxiety reduction. However, effect sizes suggested a greater decrease in state anxiety for the fear-odour group, and participants exposed to any body odour rated the practice as significantly more helpful. A larger trial is recommended.