During the witchcraft persecutions in Europe, inquisitors
were said to have sometimes put an accused witch in a bag,
which was then strung up over the limb of a tree and set swinging.
When witches learned about this punishment they experimented
with it themselves and found that the sensory deprivation
or confusion of senses it caused induced hallucinatory
experiences. A similar technique has long been used by shamans
and dervishes and is sometimes known as dervish dangling.
It involves being suspended by a rope tied around the
Modern researchers have followed up on this insight and
developed, among other devices, the ASCID (Altered States of
Consciousness Induction Device). The ASCID was devised by
Robert Masters and Jean Houston of the Foundation for
Mind Research. This technological-age witches cradle is a
metal swing in which the subject stands while blindfolded and
wearing earplugs. The motion of the swing exaggerates the
slightest movement of the occupant. Profoundly altered states
of consciousness involving hallucinatory visions and sensations
often take place within 20 minutes.