A psychomanteum is a mirrored room specially set up to communicate with the spiritual realm. Reflective objects or surfaces, such as blood or water, were considered a conduit to the spiritual world in ancient times.
Sometimes described as an apparition booth, the psychomanteum dates back to ancient Greece, where a person would gaze into a still pool of water. This silent and steady gazing into a reflective pool would produce apparitions or visions. In 1958, the Classical Greek archaeologist Sotiris Dakaris found accommodation near the Dodona oracle spoken of by Homer and Herodotus, where supplicants would wait their turn at the oracle in complete darkness. An extensive maze led to a long central apparition hallway where the experience took place. There Dakaris found the remnants of a bronze cauldron ringed with a banister which made it appear that the people who were seeing the apparitions would be gazing at the cauldron.
The room is set up to optimize psychological effects such as trance. Its key features are low light or near darkness, flickering light, and a mirror. The dimness represents a form of visual sensory deprivation, a condition helpful to trance induction, the undifferentiated color without horizon producing the Ganzfeld effect, a state of apparent blindness. The Ganzfeld experiment replicates the conditions of a psychomanteum where a state of trance may be induced by a uniform field of vision. In the way of strobe or flashing light, stimulus is provided by indirect, moving light in the psychomanteum. Flickering candles or a lamp are sometimes recommended to induce hallucination. It is supposed the indeterminate depth of the mirror’s darkness allows the eyes to relax and become unfocussed, a state that reduces alertness.
Dr Raymond Moody, author of the 1981 book about near death experiences Life After Life, included the psychomanteum in his research in trials of 300 subjects which he recorded in his 1993 book, Reunions. Moody viewed the room as a therapeutic tool to heal grief and bring insight.