Applying Recurrence Plots to Analyze Heart Rate Signals in Experienced Meditators

The current study analyses the dynamics of the heart rate signals during specific psychological states in order to obtain a detailed understanding of the heart rate patterns during meditation. In the proposed approach, we used heart rate time series available in Physionet database. The dynamics of the signals are then analyzed before and during meditation by examining the recurrence quantification analysis. The results show that the measures of recurrence plots are increased significantly during meditation (p<0.05), which indicates that the dimension of signals are decreased during meditation. In general, the results reveal that the heart rate signals of experienced meditators transit from a chaotic, highly-complex behavior before meditation to a low dimensional chaotic (and quasi-periodic) motion during meditation. This can be due to decreased nonlinear interaction of variables in meditation states and may be related to increased parasympathetic activity and increase of relaxation state.