Some animals, like earthworms, snails, and spiders, have nerves
but not actual brains. A one-year-old child's brain weighs about
2 pounds (950 g), ten times the weight of a dog's brain. The
primate cortex is so large that it has to be folded to fit
inside the skull. That's why the surface of the brain is
wrinkly. The nervous system runs on electricity, but the levels
are low. Brain signals involve less than one-tenth the voltage
of an ordinary flashlight battery. AT THE MUSEUM See how good
you're at recognizing emotions. How fast can you catch a falling
ruler? Measure your reaction time. Take the jellybean test to
see how your sense of smell enhances taste. Use Braille to
create a message for a friend. Explore your nerves by creating a
life-sized drawing. Try these trippy experiments to fool your
brain. Scientist Rob DeSalle answers kids' questions about the
brain! Test your sight and memory with these brain games.