Morse studied brainwave entrainment using audio and visual stimulation, known as audio-visual entrainment (AVE) and its effects on reducing stress during root canal dental work. He compared three groups of root canal patients: patients that received the typical instructions before the procedure (controls), patients that received 10 Hz visual stimulation and patients that received both the 10 Hz visual stimulation and relaxing music. He recorded the heart rate and GSR of participants during the root canal procedure. And as expected, all three groups experienced the most anxiety while receiving the "freezing" injection. However, the group that received visual stimulation and music had the lowest heart rate throughout the root canal procedure. Figure 1 shows the heart rate of the three groups. Notice the high heart rate in the control group compared to the much lower heart rate of the stimulation plus music group. The baseline of the GSR recordings in Figure 2 is the average of all three groups. The results are compared to that overall average and fluctuate above and below that average. Note that the stimulation plus music group was close to the average by the time they reached the drilling stage of the root canal whereas the controls continue to be anxious.