Every day our brain helps us avoid dangers and think through complex problems. The brain processes our world through signals known as action potentials. Our increasing knowledge of how action potentials help in computing images and dispensing information may eventually lead us towards determining the speed of thought.

Our brain is made up of networks of neurons that send signals through action potentials (AP), which you can learn more about from this video from the Harvard Extension School. At any given moment, a neuron may be receiving signals or inputs from hundreds of other neurons around it. Signals sent though APs can occur at different speeds depending on the myelination of the axon. For instance, increased conduction velocity as a result of myelination. We can increase the speed of responses through practice and repetition. When we are learning to read, we think through every letter and pause to formulate the sound associated with it. Through practice, we can read words through sight recognition as quickly as a few tenths of a second. This is one way our brain learns to read. After learning new words, the brain sees them as pictures.

 Most of our rapid responses become instincts or quick reflexive movements. Imagine a batter waiting at the plate for a ball approaching as fast as 90 miles per hour in as little as four tenths of a second. The batter must visualize the ball approaching, identify the location and speed it is approaching and then determine whether or not to swing at the approaching ball. All of these thought processes can take up to 400 milliseconds leaving little time for error or extra thought. These responses become faster as we practice and repeat the act of hitting the ball.

 What if that fastball approaching has hit us in the past? When we are faced with a threatening or fearful stimulus, we can trigger activity in the limbic system. Some areas activated include the amygdala, where emotions like fear are perceived, the hippocampus, where memories are formed and recalled, and the inferior parietal lobe, which is involved in the interpretation of sensory information. Evolutionarily, fear is beneficial as it helps protect us from dangerous situations. Read this article to learn how our brain processes fear. The hippocampus, is our memory center and helps us remember a fearful stimulus if we encounter it again. We can also specifically encode contextual fear memories in our hippocampal-amygdala circuit, providing a specialized memory.

 Neurons are constantly communicating and coordinating the experiences of our daily lives. They allow us to breathe deeply, to read these words, and to hit a fastball approaching us. As we learn more about the intricacies of the brain, we get closer to quantifying the speed of thought. Perhaps you will be the one to solve this age-old question.

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