The human brain is a knot of 100 billion neurons and support cells. We can store a lifetime of memories there. We can use it to write sonnets and build airplanes. Sure, an elephant's brain is larger, weighs more, and has more neurons, but elephants also lack our abilities. Intrigued? Scientists sure are. That's one reason why they are mapping the human brain, a substantial project that could take decades to complete.
Brain mapping attempts to relate the brain's structure to its function, or finding what parts give us certain abilities. For example, what aspect of our brain allows us to be creative or logical? This is called localization of function.
In mapping brain functions, scientists use imaging to watch the brain working on various tasks. Charles Wilson, a neurobiologist at the University of Texas at San Antonio, explains localization of function this way:
There's part of the brain that has to do primarily with vision and other parts that have to do primarily with sound. Now, can we look in the vision section and say, Is there a special part of the brain that detects red objects and another that detects green objects? Or does the same area detect objects of both colors?
Brain mapping also looks from the outside in. It examines how our environment changes our brain's structure by studying, for instance, how the brain changes physically through the learning and aging processes. Brain mapping also examines what goes wrong physically in the brain during mental illnesses and other brain diseases.
Finally, brain mapping aims to give us a thorough picture of our brain's structure. Google Earth shows us satellite images of our planet and zooms in to continents, countries, states, cities, highways, streets and buildings. A complete structural map of our brain might be similar. It could show us our whole brain; all the regions, functional lobes, specialized centers, thick neuron "bundles" connecting brain parts, neuron circuits, single neurons, junctions between neurons and finally, neuron parts. Scientists are still developing the parts that might form this massive map.
Brain mapping is a collection of many different tools. Researchers must collect images of the brain, turn those images into data, and then use that data to analyze what happens in the brain as it develops.
Read on to learn how researchers map the brain.