Hello Learning123,
In my EMDR sessions a few years ago, used hand held pulsing devices, and headphones. The beats in the headphones and the pulses in the hand held devices were synchronized. My therapist and I used a protocol before and after each session, establishing a "safe place". In EMDR I was allowed to "surf around" through two distinct instances of trauma. One from age 4, the other from about age 8 or 9. The sessions helped me find memories and emotions, processing grief related to the events.
EMDR is used and mentioned with a cautionary note. It can "un-cork" a lot of stuff all at once. It is recommended - I believe - for single instance type trauma. Still, to a degree, EMDR helped me. Am a CPTSD sufferer. I still have to work on healing my trauma. And I still have to manage (or attempt to cure) my massive life-long anxiety disorder; PTSD.
If you do a web (google) search for EMDR a lot of stuff comes up. If you go into You Tube, and do a search such as: emdr sessions, there are video's. Hope this helps give you a picture of EMDR. Good luck and best wishes on your path to a better life.