Psychology / Unit 3: Sensation and Perception
3.6 Illusions and Perceptual Errors
Notes
- Illusions are misperceptions that show how the brain interprets the world. They are not signs of a faulty brain.
- The Müller-Lyer illusion: two lines of equal length look different because of arrow ends. The Ponzo illusion: converging lines make a far object look bigger.
- Phi phenomenon: stationary lights flashing in sequence appear to move (used in movie signs).
- Inattentional blindness: failing to notice an obvious object when attention is elsewhere. Change blindness: failing to notice a change in a scene.
- Context, culture and expectations can shape what we perceive.
Practice
A driver talking on the phone fails to notice a pedestrian in plain view. This is an example of:
Attention focused elsewhere caused her to miss a visible object.
A neon sign shows lights turning on one after another and looks like moving arrows. This is the:
Rapid sequential flashing produces apparent motion.
What do perceptual illusions mainly demonstrate?
Illusions show normal perceptual processes leading to errors.
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