Stroboscopic motion consists of discrete, successive changes of stimulus positions which lead to the perception of continuous motion. It is the basis for perceived motion in movies (cinema). With increasing time interval, the percept changes to partial moving and “pure motion” (phi phenomenon) to optimal motion.

The flashing lights on a cinema marquee, which seem to move inward toward the lobby and entice us to follow them, are an example of apparent movement.

The stroboscope is a mechanical instrument that created an illusion of movement by quickly interchanging two faintly different pictures. This stroboscopic movement, also known as the phi phenomenon, compelled Wertheimer to ask how structuralism could explain the illusion of movement which he had observed.

When we look at something that isn’t moving, the motion neurons are all still firing, but the neurons sensing different directional motions are firing at the same rate, canceling each other out. The brain adapts, and it takes fewer neurons to make us aware of the same effect.

Reverse phi illusion is the kind of phi phenomenon that fades or dissolves from its positive direction to the displaced negative, so that the apparent motion human perceive is opposite to the actual physical displacement. Reverse phi illusion is often followed by black and white patterns.

Persistence of vision is the optical phenomenon where the illusion of motion is created because the brain interprets multiple still images as one. When multiple images appear in fast enough succession, the brain blends them into a single, persistent, moving image.

Phi phenomenon : The illusion of movement created by presenting visual stimuli in rapid succession.

Max Wertheimer (1880–1943), Kurt Koffka (1886–1941), and Wolfgang Köhler (1887–1967) founded Gestalt psychology in the early 20th century. The dominant view in psychology at the time was structuralism, exemplified by the work of Hermann von Helmholtz (1821–1894), Wilhelm Wundt (1832–1920), and Edward B.