Question

"When the lights are turned on in a sequence, they appear to move". This phenomenon is known as:

• A. Autokinetic effect
• B. Phi-phenomenon
• C. Muller-Lyer illusion
• D. Perceptual set

Hint:

Think of old movie theater marquee signs with chasing lights. Those lights aren't actually moving; they are just blinking in sequence. That's a perfect real-world example of the Phi-phenomenon.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The question describes an illusion of apparent motion, where a sequence of stationary stimuli gives the impression of movement.
Step 2: Detailed Explanation:
(A) Autokinetic effect: This is the illusion that a single, stationary point of light in a dark room is moving. This is not caused by a sequence of lights.
(B) Phi-phenomenon: This is the illusion of movement created when two or more adjacent lights blink on and off in quick succession. The perception is of a single light moving between the two locations. This is the basis for motion pictures and many animated signs. It perfectly matches the description.
(C) Muller-Lyer illusion: This is a famous optical illusion concerning the perception of length, where lines with arrowheads pointing inwards or outwards appear to be of different lengths.
(D) Perceptual set: This is a predisposition to perceive things in a certain way, based on expectations and prior experiences. It is a top-down processing influence, not a specific visual illusion of motion.
Step 3: Final Answer:
The phenomenon of perceiving motion from a sequence of flashing lights is called the Phi-phenomenon.