Plexing was a Betazoid relaxation technique that consisted of the stimulation of neural pressure points to relieve anxiety.

One plexing method that was effective for Humans is stimulation of the nerve cluster behind the carotid artery that stimulated a part of the brain that released natural endorphins. Troi taught this technique to Lieutenant Barclay in 2369, to help him with his fear of transporters. (TNG: "Realm of Fear")

After Troi saw Captain Picard, Data, and Geordi La Forge "frozen in time" she was stressed and performed plexing on her own. (TNG: "Timescape")