One explanation for the universality of these symbols is that they are entopic images - artifacts of the eye and visual system that are perceived during trance/

One explanation for the universality of these symbols is that they are entopic images - artifacts of the eye and visual system that are perceived during trance/psychedelic states. Maybe associated with a widespread shamanic religion of this time period? http://entheology.com/research/entoptic-imagery-and-altered-states-of-consciousness/ http://entheology.com/research/entoptic-imagery-and-altered-... https://en.wikipedia.org/wiki/The_Mind_in_the_Cave https://en.wikipedia.org/wiki/The_Mind_in_the_Cave