What is Phi Phenomenon?
The PHI Phenomenon is an optical illusion of seeing individual objects in constant motion when viewed quickly in succession. The PHI phenomenon explains why light bulbs arranged in a circle seem to spin when one light after another blinks only once.
Even with only two elements, the Phi-phenomenon can be observed more reliably if a negative interstimulus interval (ISI) is used; If the periods during which the two elements appear overlap slightly.
In that case, the viewer may see the two objects as stationary and unconsciously believe that the reappearance of the stimulus on one side means that the object previously displayed in that position has reappeared, as observed with beta movement, and that the object from the opposite side has just moved to a new position.
The Phi phenomenon played an important role in Gestalt psychology, as it changed the way perception is studied. Illusions such as the Phi phenomenon continue to help scientists find new ways to study the way the human brain and visual system understand and interpret information.