Read First

Abstract

● Some of them can be found on many Websites and seem to be treated as if they were in the public domain; typically, we added "Source: unknown" to these images ● Other images are taken from books, such as Roger Shepard's book Mind Sights: Original Visual Illusions, Ambiguities, and Other Anomalies. Of course, the copyright belongs to the respective authors. ● The remainder of the images has been redrawn by us according to originals found in journals or textbooks; these images are not in the public domain but you may ask us for permission to use them.