White and Gray Matter

Have you ever wondered about the difference between gray matter and white matter in the human brain? Dr. Amen, using a computer analogy, put it this way: “White matter is the tissue through which messages pass between different areas of gray matter within the brain. The gray matter can be thought of as the actual computers themselves, whereas the white matter represents the network cables connecting the computers together.” Obviously, both are important to brain function. Using a highway metaphor, think of the brain’s white matter as a pathway that has been paved with myelin, the brain’s asphalt. Paving a road in the literal world makes it easier to navigate safely and typically allows for faster travel. A similar situation occurs in the brain. Estimates are that messages travel across brain pathways at speeds of 200 miles per hour, which breaks down to about 400 feet per second. Pretty amazing!