Your Thinking Brain

Part of the Brain: The Inside Story exhibition.

The Thinker by Rodin Bronze and marble sculpture, 1902

"I think; therefore, I am." --Rene Descartes, French mathematician and philosopher (1596-1650)

If there is one thing that makes you different from other animals, it is your ability to think. Humans don't just react to the world as it is: We reflect on the past, imagine what could be, and then plan ways to make our thoughts become reality. Our brain's advanced outer layer, or cortex, enables us to remember past events and predict the future consequences of our actions before we make decisions. We can think about thinking, and use language to exchange these thoughts with others.

How it Works

Your brain is key to your intelligence. There are many different ways to define and measure intelligence, though, because it involves many kinds of thinking and uses many parts of the brain. Intelligence includes things like processing speed, memory, empathy, creativity, and connectivity--and the ability to knit these all together. Where does your unique, individual intelligence come from? Some of your abilities are encoded in your DNA. But your brain is also shaped by your individual experiences--the interaction between your genes and your environment.

Here are some critical functions that your thinking brain oversees:


The human brain is built for language. But language doesn't just communicate our thoughts. Language also helps make those thoughts possible--by providing the concepts we think with and rules for linking them together. What differentiates our ability to use language from the ways in which other animals communicate?



Memories are the refiring of the same neurons that fired when you first had a particular thought or experience. You can actually see changes in the neurons when memories form. Synapses can grow stronger as you learn. But memories are often messy and unreliable. So why, then, do memories exist?


The powers of your brain are astonishing. You can live in the moment, reflect on the past, or imagine the future. You can allow your thoughts to wander in new directions--or train them to shut out the world and focus within. How does your brain help you reason, plan, make choices, and set your mind on your goals?