For over a century scientists and clinicians have proposed mechanisms to explain the phenomenon associated with hypnosis. The key theories of hypnosis, historical and current, are presented here. For the more recent models some knowledge of cognitive psychology is useful. Within psychology most current models of how the mind works what is termed 'executive function' make use of the concept of an executive control system (Norman & Shallice, 1980, 1986) (a description of what is meant by executive control is given on this page).
A key debate in hypnosis throughout the twentieth century has been between 'state' vs. 'non-state' theories, properties of these types of theories are given below. Recently attempts have been made to integrate findings from both of these positions.