Here are some suggested books and films about this topic. Not all of them are easy to obtain, but we've tried to link places to find them.
2015 Reprint of 1934 Edition. Full Facsimile of the original edition. Not reproduced with Optical Recognition Software. Comprises Chapter XVI of Hall's "Man: The Grand Symbol of the Mysteries." Scientists refer to the pineal gland as the "atrophied third eye."
Strassman's research connects DMT with the pineal gland, considered by Hindus to be the site of the seventh chakra and by Rene Descartes to be the seat of the soul. DMT: The Spirit Molecule makes the bold case that DMT, naturally released by the pineal gland, facilitates the soul's movement in and out of the body and is an integral part of the birth and death experiences, as well as the highest states of meditation and even sexual transcendence.