Phi Phenomenon

Modified: 2024-06-12 10:02 PM CDST

• Would you like to take in a phi phenomenon tonight?
  • What might that question entail?
  • Well, it could be an invitation to a movie.
  • Movies consist of the rapid presentation (24 frames/sec or higher) of still pictures.
  • We perceive motion from that rapid succession of pictures.
  • That is one example of the phi phenomenon.

• The QuickTime movie on the main page shows a much simpler version of the phi phenomenon.
  • Two yellow circles flash on and off alternately.
  • Yet we see a yellow dot sliding back and forth across a green background.
  • At the end, another example of perceived motion occurs.
  • The words "The End" appear to approach the viewer.
• Both examples show how the brain is taking visual information and interpreting it as movement. Special effects in movies, i.e., "Anaconda," "Fourth of July," and "Godzilla" exploit the built in perceptual rules we possess.