The spirals from Newgrange. Those are indeed claimed to "resemble phosphenes" in Does the Nervous System Have an Intrinsic Archaic Language? which this person posted in another comment. They are neolithic, which is a very long way from paleolithic, not just in time but in development of ideas. The paper has another montage of images with the Gundestrup cauldron in it! That was made in the small hundreds AD. It's just a grab-bag of anything that looks shamanic to support the thesis "maybe they were tripping", about everybody everywhere throughout time, and yes, fair point, maybe they were tripping, it's worth bearing in mind. Also, maybe they were stupid. So what? Is this a solution to any problem?