In 1956 , British psychiatrist Lionel Penrose and his son , mathematician Roger Penrose , submitted a short article to the British Journal of Psychology titled `` Impossible Objects : A Special Type of Visual Illusion '' .
In 1956 , British psychiatrist Lionel Penrose and his son , mathematician Roger Penrose , submitted a short article to the British Journal of Psychology titled Impossible Objects : A Special Type of Visual Illusion .