Implied herein is that b-endorphin may be more active after a rest period also. It is noteworthy that while hypnosis research has been conducted for over 200 years there are as yet no mathematically formulated functional relationships. This may be because until now hypnotic research has ignored the time parameter that has been of essence in the development of the mathematical approach in the physical and biological sciences where functional relationships between variables are measured over time. The inverse relationship between hypnotizability and natualistic trance time that has been independently validated in several studies by Rossi, Lippincott and Sommer would appear to be a basis for such a functional relationship between hypnosis and chronobiology. I would like to suggest we could support the use of time in hypnosis by noting historical information about the early use of rhythms in hypnotic induction.
Early texts have pictures of the use of the metronome and flashing lights for hypnotic induction.
Both of these methods, of course, are rhythmic methods of induction via the sensory modalities of sound and vision. Esdaile used periodic passes over the body for deep hypnotic induction for surgery. This, of course, is a rhythmic method of hypnotic induction that uses the tactile modality. This was as long as his study was conducted however. Hull notes that future research needs to extend this time beyond 10 minutes.