Fig 7. 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 a 5-min-increment-based measure was hardly to capture the happenings of 2-min non-meditation state among the meditation states, 1-min-increment-based measure could clearly catch the short-time changes of meditation state.