One of the goals of many neurofeedback protocols is broadband global synchrony. Nested frequencies often lead to increased phase resets. Particular frequencies can be chose to increase long distance phase synchrony which result in increases in phase resets.
When we couple two different oscillators, their phase relationship can drift apart. A synchronized pulse can shift the phase of one or both of the oscillations, which can result in the oscillators going back in phase or phase-locking for a period of time.
Phase resets occur when the timing of the theta and alpha frequencies simultaneously increase or resets, 2-3 times the normal amplitude. It’s suggested that phase resets are a sign that emotional material is being processed. The subjective accounts are that there has been some type of insight or acceptance.