In an apparent motion demonstration, two pictures are used. In one picture, a person's fist is located behind his head; in the other, the person's fist is located in front of their face at the same height. When slowly alternating between these pictures (less the five times a second), what apparent motion would result
A) The fist would appear to go around the side of the head.?
B) The fist would appear to "magically" pass through the head.
C) The fist would appear to smash the head.
D) No apparent motion would occur because the alternation is too slow.

Question

Quizplus · Accepted Answer

This type of illusion is called the phi phenomenon, and it causes the brain to perceive motion when there is none. In this case, the fist will appear to move around the side of the head as the two pictures switch back and forth.

In an Apparent Motion Demonstration, Two Pictures Are Used