Sensation and Perception
Optical Illusions
Optical illusions can not only challenge your mind, they also reveal the inner working of the brain. Learn more about some of the most famous optical illusions and find out what these visual phenomena reveal about brain functions.
What is the Trichromatic Theory of Color Vision?
Color is one of the most pervasive perceptual qualities in our lives. But how to we perceive color? Learn more about the role the trichromatic theory of color perception plays in color vision.
What is the Opponent-Process Theory of Color Vision?
The opponent-process of color vision explains some aspects of color perception not covered by trichromatic theory. Learn more about the opponent-process and see examples of the theory at work.
How to Make Your Eye Feel Closed When it Isn't
Learn more about how to perform an intriguing illusion in which your eye will feel closed when it is actually opened.
John Krantz: Sensation and Perception Tutorials
Discover tutorials and demonstrations on a variety of topics in sensation and perception including linear perspective, figure-ground perception, spatial summation, and color aftereffects. These examples are a great resource for understanding different concepts involved in the perceptual process.
Color Matters
Find information about color and how it affects the brain, body, vision, design, and art.
Blind Spot Test
Experience your visual blind spot in action in this quick and easy test.
What Is an Afterimage?
Afterimages are a type of optical illusion that involves continuing to see something that is no longer there. Learn more about how afterimages work.
10 Cool Optical Illusions
Optical illusions can be fun, but they are also a great way to learn more about the brain and perception. Here are ten cool optical illusions to try.
The Müller-Lyer Illusion (How It Works)
In the Müller-Lyer Illusion, two lines appear to be of different lengths even though they are the same. Learn more about how this optical illusion works and what it reveals about the brain.
The Moon Illusion - Some Possible Explanations
Why does the moon appear larger when it's on the horizon than it does higher in the sky? Learn more about how this fascinating illusion works.
The Lilac Chaser Illusion
The lilac chaser illusion demonstrates a number of different things about the visual system and the brain. Learn more about how this fascinating illusion works.
The Negative Photo Illusion
The negative photo illusion is a fun and fascinating way to learn more about the brain and perceptual system. Check out the illusion and learn more about how it works.