The Gateway Tapes were developed by the Monroe Institute (TMI). The Monroe Institute is a renowned institute for consciousness studies since its formation. The Gateway Tapes were designed to instigate states of hemispheric synchronization, also known as Hemi-Sync. Robert Monroe claimed that the technique synchronizes the two hemispheres of one's brain, thereby creating a 'frequency-following response' designed to evoke certain effects. Hemi-Sync has been used for many purposes, including relaxation and sleep induction, learning and memory aids, helping those with physical and mental difficulties, and reaching altered states of consciousness through the use of sound.
In 1983, Lieutenant Colonel Wayne M. McDonnell submitted a classified report titled "An Analysis and Assessment of Gateway Process." This was the US Army's and CIA's investigation into the practical applications of the Gateway Tapes. If agents could be quickly trained to have out-of-body experiences, and the results could be dependably replicated, it would be an invaluable tool for intelligence-gathering and espionage.
However, the McDonnell's report explores the theoretical framework that may allow for supernatural events like remote viewing or out-of-body experiences to occur. He explores biomedicine, quantum mechanics, theoretical physics, and Newtonian physics, in an attempt to identify how these events could occur. His grand theory explores ideas like the holographic world, the manifestation of will, and more.