Results
Figure 3 provides simultaneous HRV and EEG power spectral density (PSD) data from a subject during the 5-minute period immediately prior to the FF-intervention and the 5-minute period immediately after the initial FF-intervention with continued focus on sincerely feeling a positive emotion. Note that, before the FF, the EEG data recorded from the CZ point has only nominal activity in the ~0.1 Hz range. However, after the FF intervention, when the subject is in the entrained state, the HRV entrainment signature suddenly appears in the EEG.

Further, we have also observed that when the entrainment state is practiced and maintained by a subject for increased time ratios, the very low frequency (VLF) peak can occur in the EEG even when in the absence of HRV entrainment. Figure 4 illustrates this point.

Figure 5 provides an example of a subject whose heart function is not fully entrained. Note that the three main HRV spectrum peaks (lowest plot) appear non-linearly amplified in both the respiration and PTT data. However, some, but not all, of the HRV peaks are present in the EEG data taken from various locations.

Figure 6 data is found when this subject is in the fully entrained mode. Figure 6a shows filtered EEG (CZ), respiration and HRV. Figure 6b shows PSD plots for each time wave while Figure 7c shows the cross correlations for each of the oscillator pairs, HRV and EEG, HRV and respiration, plus EEG and respiration. A high degree of coupling between these three biological oscillator systems is demonstrated when a strongly entrained heart function mode is present.

Figure 7 presents an example of entrainment between the HRV and EEG (CZ) while the respiration is not yet fully entrained to the HRV or EEG. It is, however, being "frequency-pulled" toward the HRV frequency. This illustrates the two-way interaction between respiration and heart function. It is well known that respiration affects heart rate; however, it is less well understood that heart rate also affects respiration via the baroreceptor system [22].

Figure 8 provides evoked potential plots from several specific brain locations. These all had a start time locked to the R-wave of the ECG. The bottom plot shows the ear-recorded pulse wave associated with this R-wave. Note that its maximum occurs 240 ms after the R-wave maximum.

Figure 9a shows an example of a waterfall plot of EEG (T6) evoked potentials for a 10 minute period. Each of the 38 traces in the plot consists of 180 trials. These evoked potentials were generated by averaging together background EEG synchronized to the peak of the R-wave of the ECG. During the first half of the plot the subject was in the normal state and then shifted to the entrainment state via the FF-intervention for the remainder of the time. Note that the first and last curves (Fig. 9b) of this waterfall sequence are significantly different from each other. The transition occurs at the FF point. These shifts in the EEG may be a key to understanding the shifts in perception and increased intuitive awareness reported by most people after practicing the Freeze-Frame technique.