P300 and Heart Rate Variability Recorded Simultaneously in Meditation

Sympathetic activation is required for attention. Separate studies have shown that meditation (a) improves attention and (b) reduces sympathetic activity. The present study assessed attention with the P300 and sympathetic activity with heart rate variability (HRV). Forty-seven male subjects (group mean age +/- SD, 21.6 +/- 3.4 years) were assessed in 4 mental states: (a) random thinking, (b) nonmeditative focusing, (c) meditative focusing, and (d) defocused meditation. These were recorded on 4 consecutive days. HRV, respiration, and P300 event-related potentials (ERPs) were recorded before and after the sessions. Data were analyzed with repeated-measures analysis of variance followed by post hoc analysis. HRV showed a significant increase in low-frequency (LF) power, decrease in high-frequency (HF) power and an increase in average heart rate based on the average R-R interval after meditative focusing, compared with before. In contrast, the average heart rate decreased after defocused meditation compared with before. There was a significant increase in the P300 peak amplitude after meditative focusing and defocused meditation, with a reduction in peak latency after defocused meditation. These results suggest that after meditation with focusing, there was sympathetic arousal whereas after defocused meditation, there was a decrease in the average heart rate while participants carried out the P300 auditory oddball task sooner.