What's in a Brain?
Like the Earth's crust, the brain has its own specialized surface called cortex. Instead of plants, animals, and ecosystems found on Earth, in cortex you find neuron cell bodies, and synapses, the connections between neurons.
In much the same way that a mountain has more surface than a flat area of land, cortex is folded, allowing more to fit within the skull. Higher order animals have more folded brains and thus more cortex. More cortex means more neurons, which most researchers think results in greater intelligence.
Different regions of cortex are connected by axons, in a region of the brain called white matter. The brain is about 50% white matter and 50% cortex.
Functional maps of cortex reveal that different regions of brain specialize in certain types of information processing. For example, motor cortex transfers intent to move into physical movement and auditory cortex relays hearing to the rest of the brain.
Animals with super senses tend to have more cortex devoted to their special ability. Consider man's BFF: dogs. They have relatively 40 times more brain devoted to smell than humans.
If an animal has amazing vision, chances are it has a high proportion of cortex devoted to vision. Amazing hearing? Auditory cortex. Infrared vision? A totally new part of the brain that isn't present in animals that cannot see in infrared. Next time you're watching a nature show or encountering a cool creature in the wild, think about which specialized functional regions of cortex are prominent based on the animal's special abilities.
Not all cortex is specialized and tied to specific sense. Intelligent animals tend to have relatively more areas of generalized cortex, the most important of which is called prefrontal cortex (PFC). PFC is found behind the forehead and is active during a myriad of complicated activities ranging from introspection to problem solving. Many researchers hypothesize that a sense of self is stronly linked to activity within PFC.
We know a great deal about the brains, yet we are still unable to answer many of the most interesting questions relating the brain to the mind. While the brains of humans, certain apes, mice, and c. elegans are well studied, we know next to nothing about the brains of most animals on Earth. It’s therefore critical to support conservation not only to preserve these wonderful critters, but also so that we can potentially learn more about ourselves from the vast diversity of Earth. We've learned more about the brain in the past two decades than in all of human history. There has never been a more fruitful time to study the brain. Perhaps future discoveries will come from you!
The citizen science game Eyewire invites anyone, anywhere to help map the brain. This free, online game crowdsources neural reconstructions through the format of a 3D puzzle game.
Solve puzzles to map neurons. Hundreds of thousands have signed up. Eyewirers have even charted new circuits and even discovered 6 new types of neurons. Join us at eyewire.org!