Decoding the Brain

STEPS TO UNDERSTANDING BRAIN ACTIVITY AND HOW THE MIND WORKS

- Abha and Deepa Jain

Your brain looks like a pinkish-brown blob of gelatin and may seem just as silent. Don't be fooled by this apparent quietness, though. Around 86 billion nerve cells called neurons form the building blocks of this organ-and they speak. They converse when you're playing, eating, or just sitting still. Some jabber while you sleep, too.

But neurons don't communicate with sound, as you do when you talk. They speak through tiny bursts of electrical energy called action potentials or spikes.

Neurons in the brain send and receive signals using action potentials. It's almost like a language. Neurons in your eyes, ears, and skin produce action potentials in response to lights, sounds, and touch, respectively. And neurons don't just speak to one another. Many relay messages to and from your muscles, telling them whether to contract or relax. Through spikes, neurons in your brain control your whole body, from head to toe.

Coding With One Letter?

All spikes aren't identical. The duration of the signal ranges between one to several hundred milliseconds. (One millisecond equals a thousandth of a second.) Spikes also travel at different speeds. Some spikes plod along. Others whir faster than race cars.