While I have previously wondered about the fabric shape, I don't think the similarity is great enough. Unless there is significant variation in brains, the silh

While I have previously wondered about the fabric shape, I don't think the similarity is great enough. Unless there is significant variation in brains, the silhouettes differ in way too many places and only really share a couple of major features. However, the shape is similar enough for me to accept anatomical inspiration. I could see him wanting to draw something around god, sketching a cloud, and then remembering the shape of a brain and going with that. If indeed the artist was fascinated with anatomy, it would make sense that anatomical shapes could be found all over his more freeform work.