> CNNs have trouble distinguishing things like a spiral from a set of concentric circles because locally they look the same. So does the human visual system; s

> CNNs have trouble distinguishing things like a spiral from a set of concentric circles because locally they look the same. So does the human visual system; see e.g. https://en.wikipedia.org/wiki/Fraser_spiral_illusion https://en.wikipedia.org/wiki/Fraser_spiral_illusion .