Michael Harner on Extractions

From his FSS website:

Depossession is related to extraction but it's not the same thing. From a shamanic point of view, it's very important to get out of the Middle World when journeying for spiritual purposes. In the old days, shamans journeyed in the Middle World to see how relatives were doing at a distant place or to locate the herds of migratory animals. But most of our work today is in the Upper and Lower Worlds where shamans have voyaged since ancient times. Shamans often prefer not to draw on the spirits of the Middle World because many of them are confused and lacking in power. Going to the Upper or Lower Worlds, one reaches spiritual beings of compassion, power, and wisdom.

Shamans who do another type of healing help the dead as well as the living. These shamans are called "psychopomps," or conductors of souls. Remember, from a shamanic point of view, when you're comatose, you're dead. So the shaman, in the case of comatose persons, would seek them out and see if they wanted to come back. Shamanism is not a system that intends to keep people in this ordinary reality whether they like it or not, because the shaman knows that this is not necessarily the best reality. You make the journey for the person who is comatose to find out what they want. If they want to come back, then the job of the shaman is to bring them back. But if they want to go on—or, more commonly, if they're dying or already dead—then the job of the shaman is to get them to a place where they will be content and not have them stay here, adrift in the Middle World.