A Hypnomat is a specialised chamber used to subject a Space Marine to hypnotic sights and sounds in order to train him to use his newly implanted gene-seed organs and control his metabolism. The hypnotherapy begins during Phase 6 of the Space Marine's initiation protocols.
The Hypnomat is also used to implant memories and reshape an Astartes' personality to meet the psychological demands and stresses of constant warfare. Its use is a key stage in the creation of a Space Marine.
- Dark Imperium: Plague War (Novel) by Guy Haley, Ch. 3