phi phenomenon
noun
: apparent motion resulting from an orderly sequence of stimuli (such as lights flashed in rapid succession a short distance apart on a sign) without any actual motion being presented to the eye
Word History
Etymology
translation of German φ-Phänomen
Note: The term was introduced by the psychologist Max Wertheimer (1880-1943, born in Prague, Austria-Hungary, in the U.S. from 1933) in "Experimentelle Studien über das Sehen von Bewegung," Zeitschrift für Psychologie und Physiologie der Sinnesorgane, 1. Abteilung, Zeitschrift für Psychologie, Band 61, Heft 1 (April, 1912), pp. 161-265.
First Known Use
circa 1928, in the meaning defined above
Medical Definition
phi phenomenon
noun
ˈfī- 
: apparent motion resulting from an orderly sequence of stimuli (as lights flashed in rapid succession a short distance apart on a sign) without any actual motion being presented to the eye compare apparent motion