Also known as apophany. Etymologically, both terms appear to stem from the Greek words apo (away from, apart) and phainein (to show, to make appear). It has been suggested, however, that apophenia results from a misspelling and that the proper term should be apophrenia, from the Greek words apo (away from) and phren (nerve, mind). Historically, the terms apophenia and apophany derive from the German neologism Apophänie, which was introduced in or shortly before 1958 by the German neurologist and psychiatrist Klaus Conrad (1905-1961) to denote an "unmotivated seeing of connections" accompanied by a "specific experience of an abnormal meaningfulness". Conrad uses the notion of apophenia in the context of a three-stage developmental model of "schizophrenia (consisting of trema, apophany, and apocalypse). As used in the conradian sense, and applied to the group of " sensory deceptions, it has been suggested that apophenia may be the neuropsychological substrate of "pareidolia, "auditory pareidolia, the "Dark Side of the Rainbow, and other "cognitive illusions. Today the term apophenia tends to be used in a much looser sense, not necessarily relating to psychiatric disease or to perception, to denote an excess of perceptual or heuristic sensitivity leading to the discernment of patterns or connections in random or otherwise meaningless data.
References
Conrad, K. (1958). Die beginnende Schizophrenie. Versuch einer Gestaltanalyse des Wahns. Stuttgart: Georg Thieme Verlag.
Sass, L.A. (1992). Madness and modernism. Insanity in the light of modern art, literature, and thought. Cambridge, MA: Harvard University Press.
Dictionary of Hallucinations. J.D. Blom. 2010.