There are many levels of spirit over-shadowment, from light inspiration to deep transformation and altered states of consciousness.
All modalities listed above are forms of spirit over-shadowment, this is when a spiritual being who works with you, as you develop your mediumship, step into your auric energy field and harmonize spirits frequencies with yours.
Then spirit, your loved ones, guides and helpers will use the consciousness of the medium for the purpose of sharing knowledge. Depending on the level of attunement along with the level of over-shadowment the medium has achieved, this will determine, to what degree the spiritual being will be able to use you as an instrument for direct communication.
There are many levels of spirit over-shadowment, from light inspiration to deep transformation and altered states of consciousness.
Through this connection, established between the and the spirit communicator, one develops a rapport between both of your energetic fields. The trance medium through years of dedicated practice allows the conscious mind to take a back seat and connects with the intelligence of spirit. As this connection strengthens, the subconscious mind will vibrationally link together with the spirit intelligence. Then using the physical attributes of the medium, the spirit communicator will begin the direct influence and direct a communication with those on the earth plane.
Trance is the art of suggestion and inspiration; it relies on direct and indirect communication, which includes metaphors, emotional tone and imagery. When we consider consciousness as a spectrum from a state like a deep sleep to alert wakefulness, one can begin to appreciate how we go up and down the scale and just what a complicated procedure this form of mediumship can be.
Spirit will also use the medium in this form when they want to put pen to paper in written form, by impressing the medium with thoughts and ideas. Many of our great artists have been used as instruments in this way and given us great works in verse and song as well as poetry and our most sacred and ancient texts.