This technique, formalized in the 19th century, was created in its modern form by Milton Erickson and aims to create a modified state of consciousness that allows the client to fix his conscious attention on just one point, so that all unconscious stimuli no longer affect him.

Part of his mind can then live in a trance, being able to pick up on helpful suggestions that the therapist makes, while his rational mind can rest.

This state allows him to get in touch with past events in order to be able to overcome the negative effects they may have on his present life.