An hybrid face presenting Margaret Thatcher (in Low Spatial Frequency) and Tony Blair (High Spatial Frequency) has been displayed in 1998 in the Scottish National Portrait Gallery in Edinburgh. If you squint, blink or defocus while looking at the pictures, Margaret Thatcher should substitute for Tony Blair (if this demonstration does not work, step back from the pictures until your percepts change). The inversion effect is more striking on the right than the left version of the Tatcher-Blair illusion, where the face of Margaret Tatcher blends in the background.
