BrightKidz Library
Subjects
Three senses all reporting to the same brain Three senses arranged down the left hand side. At the top an eye, an almond outline with a round pupil. In the middle an ear. At the bottom, for touch, a fingertip pad with the loops of a fingerprint on it, resting on a small ridged surface. A dotted line runs from each of the three across the picture to a brain on the right, so all three messages arrive at the same place.

Super Senses: You're Amazing

About 4 minutes

Sight, hearing and touch all work the same basic way: something from outside you — light, sound waves, or pressure — meets a body part built to pick it up, and that body part turns the signal into something your brain can use.

Sight: Seeing the World

Light bounces off objects and lands inside your eyes, where special cells sort it into colors. Your brain takes it from there and works out what you are looking at. Blinking keeps the whole system clean and wet.

Hearing: Listening to Sounds

Sound travels as waves, like ripples spreading across a pond, and your ears turn each wave into a message your brain can read. Loud sounds and quiet sounds are simply bigger and smaller waves. Your ears also work out which direction a sound came from, using the tiny gap between it reaching one ear and then the other.

Touch: Feeling Everything

Your skin is covered in nerve endings that report hot, cold, soft, and rough to your brain. Your fingertips have far more of these nerve endings packed into the same area than the rest of your skin, which is why they can tell you the most.

Every sense ends up in the same place

Here is the part that surprises people. Your eyes do not see, and your ears do not hear. They collect, and they send. The seeing and the hearing happen in your brain.

Pick a sense to see what it collects, and what it sends on.

  • Sight — light bounces off an object and lands in your eye. Special cells there sort out the colors, and your brain works out what you are looking at.
  • Hearing — sound arrives as waves, like ripples in a pond. Your ears turn those waves into messages, including which direction they came from.
  • Touch — nerve endings all over your skin report hot, cold, soft and rough. Your fingertips are packed with them, which is why they feel so much more than the rest of you.

Try it: three quick experiments

You need nothing at all for these. Do them in order.

  1. Depth. Hold one finger up at arm's length. Close one eye, then swap eyes. Watch your finger jump sideways. Each eye sees a slightly different view, and your brain uses the difference to judge how far away things are.
  2. Direction. Close your eyes and stay still while someone quietly taps somewhere in the room. Point at the sound before you look. You are using the tiny gap between the sound reaching one ear and then the other.
  3. Touch alone. Still with your eyes shut, have someone hand you an everyday object. Name it using your fingertips only. Notice how much you can tell — weight, temperature, texture — with one sense switched off.

Next time you catch something out of the corner of your eye, or point at a sound before you look, notice that your eyes and ears never actually did the seeing or hearing. Your brain did, using nothing but the signals they sent it.