Everyone who participates in our MEG studies gets to learn some awesome new things about the brain and how we can study it! See the questions below.
How do you tell what a brain is doing?
Since your brain is inside of your body, scientists can’t directly see what’s happening in your brain, so we have to study it indirectly. One way to study the brain is with tools like microscopes, like the kind you might have used in school. With a high-powered microscope, you can look at a brain’s individual cells, which are called neurons (NUR-ons). Another way to study the brain is with neuroimaging techniques, which let you actually measure the electric and magnetic fields that brains are always producing.
Why do brains produce magnetic fields? Are brains magnetic?
Magnetic fields are created when electric charges move. When you move a strong charge with a lot of motion, the magnetic field is stronger, and if you move a weaker charge with less motion, the magnetic field is weaker. Your brain is made up of around 100 billion (100,000,000,000) neurons, and each of those neurons talks to the others by sending little electric messages to each other. So when enough neurons work together to send a message, that small amount of electricity moving is enough to create a magnetic field.
If you’re interested in how magnetism works in general, see this explainer.
How strong are the magnetic signals my brain gives off?
For comparison, your heartbeat, which also generates a magnetic field, is a thousand times as strong. The earth’s magnetic field can be up to a million times stronger than your heartbeat. An ordinary refrigerator magnet is a thousand times stronger than the earth’s magnetic field. And technology like magnetic resonance imaging (MRI) uses magnetic fields which are 3 quadrillion (that’s 3,000,000,000,000,000) times stronger than the signal generated by your brain!
What does an MEG machine do?
Magnetoencephalography measures the tiny magnetic signals coming out of your brain. You can’t feel it, but your brain is constantly creating magnetic fields, because it’s always doing something, even if you’re just sleeping. Unlike in an MRI, MEG machines don’t actually produce radiation or magnetic fields — an MEG machine uses sensors to detect and amplify magnetic signals your brain generates. See “MEG for Kids” to learn more about how an MEG machine works.
