An ambiguous figure that can be perceived either as three cubes or as five cubes depending on how the perspective cues are interpreted (see illustration). See also perspective reversal. [Named after the US-born German/British psychologist Edward Wheeler Scripture (1864–1945) who published it in 1895]
Scripture's blocks. A is identical to B but inverted, as can be confirmed by inverting the page. If one of the groups is seen as three blocks, then the other will be seen as five, and whenever one of the images appears to flip over, so does the other.