The uncanny refers to a feeling of non-familiarity which has a threatening and undermining aspect. Its use in this sense can be traced to Sigmund Freud, who introduces the term in a psychological study of terror. Freud describes as uncanny that which is on the limit of the familiar, and which thereby destabilizes clear boundaries. In uncanny situations, the strange infiltrates the familiar, questioning sanity, reason and selfassurance. The uncanny can be seen as one sensation invoked by horror films or déjà vu effects-a creeping feeling of something being not quite right.