VisionPerception
The Checker Board
Look at the two squares marked A and B on the checkerboard. Which one is darker?
Games & Experiments
Discover yourself through play
Twelve interactive experiments drawn from psychology, neuroscience, and physiology. Each one reveals something surprising about how your mind and body actually work.
Tap any image to enlarge it. Reveal the answer only after you have tried the challenge.
12 experiments
Cognition
The Bat and Ball
A bat and a ball together cost $1.10. The bat costs $1.00 more than the ball. How much does the ball cost?
PerceptionCognition
How Many F's?
Count every letter F in the following sentence — read it only once: "FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS."
Anatomy
Vein Valves
Hold your forearm horizontal with your palm up. Press a finger firmly on a vein near your wrist, then slide another finger up the vein toward your elbow. Release the lower finger. What do you observe?
MemoryPerception
Paint from Memory
Look at the image for exactly 30 seconds. Then close or cover it and try to draw what you remember — as accurately as you can. When you are done, compare your drawing to the original.
SensesAnatomy
Back Sensation
Ask a partner to lightly touch your back with either 1 finger or 2 fingers held close together — without telling you which. Eyes closed. Try to identify whether it is 1 touch or 2 across 10 attempts. Track your score.
VisionAnatomy
The Blind Spot
Close your left eye. Hold the image at arm's length and focus your right eye on the cross symbol (+). Slowly move the image closer to your face. At a certain distance, the dot on the right will completely disappear.
VisionPerception
Thumb View
Hold your thumb up at arm's length and focus on a small detail on your thumbnail. Now, without moving your eyes from that detail, try to read text in the surrounding area of the room. What do you notice about your peripheral vision?
VisionPerception
Mixed Images
Place a small mirror vertically at the center of the image, perpendicular to the page. Look at the reflection combined with the other half of the image. Move the mirror slowly to the left and right. What kinds of faces do you see?
VisionPerception
Eye Image Retention
Stare at the center of the image without blinking for 30 seconds. Then immediately look at a plain white wall or a blank piece of paper. What do you see?
VisionPerception
The Rotating Pink Dot
Watch the animation and focus on the cross in the center. After a few seconds, what color is the dot that appears in place of the missing pink dot?
Anatomy
The Knee Reflex
Sit on the edge of a chair so your lower leg hangs freely. Ask a partner to tap firmly just below your kneecap (patella) with the side of their hand. What happens?