Fig 6. Time course of the SPLF on human RR-interval series with1-min increment (red solid line) and 5-min increment (green dotted line).

M and N labelled on the signal represent Meditation and Non-meditation state, respectively. It can be seen that 1-min-increment-based HRV analysis measure gives an earlier responses to the changes of meditation states than 5-min-increment-based measure.