I suppose more edumacated people have already made this connection, but it seems like Van Gogh’s art and megalithic art share a connection.
Laurie Darcus has written about the art on megalithic tombs:
Lewis-Williams and Dowson (1993), and Eichmeier and Höffer (1974) (cited in Lewis-Williams 1993: 55) have established a neuropsychological model where during altered states of consciousness, geometric entopic phenomena (often referred to as phosphenes), intrinsic to the human nervous system, are “seen” by those in the altered states. The theory has been successfully tested both under laboratory conditions and in ethnographic situations, and the stage I entopic component of the neuropsychological model seems universal.
Laurie Darcus on megalithic art
She concludes that it’s hard to say that the megalithic art is from transitory altered states of consciousness, as the chiseling of the stone would obviously span a much longer time than being high off a magic mushroom from the fields of Newgrange.
But interestingly she concludes that it does seem that this old art comes from the subconsciousness, and that societies would then build up meaning from the shapes afterwards.
I’ve no particular knowledge on Van Gogh’s un-average state of conciousness, other than the documentary Van Gogh: Painted With Words documentary that I’d highly recommend.