In 1785 C.E., the French occultist Eteilla (Jean-Baptiste Alliette) became the first professional tarot diviner. He popularized the use of the tarot as a divinatory tool to a wide audience, and was the first to develop and publish a set of correspondences, linking the cards to astrology, the four classical elements (earth, fire, water, air), and the four humors (black bile, yellow bile, blood, and phlegm). These correspondences are still useful today.
Here's what happened: The experienced psychographers showed lower levels of activity in the left hippocampus (limbic system), right superior temporal gyrus, and the frontal lobe regions of the brain during psychography compared to their normal (non-trance) writing. The frontal lobe areas are associated with reasoning, planning, generating language, movement, and problem solving, which means that the mediums were experiencing reduced focus, lessened self-awareness and fuzzy consciousness during psychography.