Persinger’s Helmet or ‘The God Helmet’ is a helmet that was created to test the creativity and the effects of subtle stimulation of the temporal lobes. Reports by participants of a "sensed presence" while wearing the God helmet brought public attention and resulted in several TV documentaries. The device has been used in Persinger's research in the field of neurotheology, the study of the neural correlates of religion and spirituality. The helmet, generates very weak fluctuating magnetic fields. These fields are approximately as strong as those generated by a hair dryer.
Persinger reports that many subjects have reported "mystical experiences and altered states" while wearing the God Helmet. His theory has been criticized by scientists and reports have had mixed opinions as and the effects reported by Persinger have not been replicated. The only attempt at replication has stated that the improper blinding of people could have resulted in similar effects to what has been described.
The God Helmet was not specifically designed to create visions of God, but to test Persinger's hypotheses about brain function. The first of these is the Vectorial Hemisphericity Hypothesis which proposes that the human sense of self has two parts, one on each side of the brain, that ordinarily work together but in which the left hemisphere is usually dominant. Persinger argues that the two hemispheres make different contributions to a single sense of self, but under certain conditions can appear as two separate 'things'. Persinger and Koren designed the God Helmet in an attempt to create conditions in which contributions to the sense of self from both cerebral hemispheres is disrupted.
Most reports from Persinger's lab consist of people sensing "presences"; people often interpreted these to be that of angels, a deceased being known to the subject, or a group of beings of some kind. There have also been reports in which the participant has experienced what they