Procotol by Somadatta, 1982
Ring of Smoke
"Since I have begun to practice more intensively on the forehead region, a new form of tunnel phenomenon occurred: repeatedly, rotating ‘rings of smoke’ appeared. Firstly there was one ring to see which rotated clockwise with one or two turns in a second, and which seemed to be of smokey or vaporous consistency – thus, it had no definite shape. Its colour was always white. Mostly this ring-shaped form – that seemed to come from the forehead region – was circular, but on one occasion it was definitely longitudinal-oval. The rotating movement was there everytime. These rings seemed to float in the space independently from each other.
Exercise: imagining a rotating Ajna Chakra"