For Real! Split-Second Decisions

Summer 2017

Think fast! If a baseball is headed for your head, your brain must process that and respond appropriately, and all this happens in a fraction of a second.

The time it takes for neural circuitry to do its part depends on a few things: the number of neurons in the brain message pathway (travel distance), the length of the neurons, and the neuron’s degree of myelination (sort of a turbo boost). Myelin acts as a blanket of insulation that wraps around segments of neurons for faster relay of information. In between each section of myelin are uncovered sections called nodes of Ranvier. (No, that’s not a mountain chain from a Tolkien novel.) As brain signals are transmitted, they jump from node to node along the long, thread-like part of the neuron called the axon. And that allows messages to arrive faster, sometimes at speeds of up to 268 miles per hour.

In our teens and 20s, our bodies enter the big leagues. They are pruning and myelinating brain connections into extra innings. All that revamping allows the brain to work many times faster than when we’re little kids.

Ever notice that some elite hitters are at the top of their game just before they retire? That’s because of another key player: prediction. From the mound, things happen so fast that a hitter only has the first few milliseconds of the pitcher’s release to judge what’s coming next. Experience teaches hitters how to read pitchers’ cues. That’s why some of the best batters get better with age.

Thank you to professors Alan Sved and Peter Strick who helped us think about all of this.

For Real! is Pitt Med's science section for preteens and the ever-curious. Is there a topic you’d like us to explore? Drop us a line: