What are brain waves?

Have you ever heard the term “brain-waves”? If you have, what comes to mind when you think of them? Do you think that they’re a made-up science fiction term? Well, they’re actually real! Neuroscientists can measure brain waves from different parts of the brain and analyze them to understand how one brain region functions or how multiple brain regions work together. Brain waves can even help us better understand different diseases and mental illnesses. 

What exactly are brain waves? Brain waves are measurements of voltage changes in the brain. These voltage changes come from the activity of the cells in the brain, mainly neurons. Neurons conduct electricity! Isn’t that so cool? That’s what makes neurons different from other cells in our body. Neurons receive information from other neurons and then they send an electrical signal down their axons, called an action potential. There are about 86 billion neurons in our brains. In order for you to see, hear, taste, walk, talk, sleep, think, feel emotions, and even breathe, different groups of neurons are constantly firing action potentials across your brain. When neurons are working together to do something, like figure out what you’re seeing, or keep your legs moving while you’re walking, they fire together. The activity of all of those neurons creates electricity in your brain that can be measured as brain waves! 

Brain waves are invisible, but scientists and engineers have invented ways of measuring them through computers, like the picture above. There are many ways to measure brain waves and they can be measured in both animals and humans. Neuroscientists can study brain waves inside animals’ brains to learn more about how the brain functions. Scientists and physicians can measure brain waves from the outside of a human’s head to learn how different parts of the brain work together, or even to learn more about diseases like epilepsy or depression. Neuroscientists use math, physics, statistics, and computer science to decode the information contained in a single brain wave. Then, they can compare information from brain waves from different parts of the brain to see if those brain regions are communicating. Neuroscientists can design experiments to test whether brain regions are involved in different functions from everything like vision to feelings and emotions. These experiments are important because the more we can understand how parts of the brain work, the more we can design medicines and treatments to help people with different neurological and psychiatric diseases.