How does your brain work?

In How Your Brain Works, authors Greg Gage and Tim Marzullo uncover the hidden electrical world inside your nervous system using DIY, hands-on experiments, for all ages

We are in the midst of Brain Awareness Week, dedicated to celebrating this most complex organ in the human body. And the workings of the brain are indeed mysterious: What are neural signals? What do they mean? How do our senses really sense? And how does our brain control our movements? 

Neuroscience researchers Greg Gage and Tim Marzullo wrote How Your Brain Works for readers to explore those very questions, offering a practical guide—accessible and useful to readers from middle schoolers to college undergraduates to curious adults—for learning about the brain through hands-on experiments. 

How Your Brain Works allows anyone to participate in the discovery of neuroscience. Gage and Marzullo help readers to learn: 

  • What does our brain do when we exercise or hold our breath?
  • How do our brains tell our bodies to jump, dance, or sing?
  • How does the brain get your attention?
  • How long does it take the brain to decide?

In honor of Brain Awareness Week, try out this easy experiment from How Your Brain Works to gain a better understanding of the brain’s reaction time:

Have your friend sit at a table with their dominant hand exposed over the edge, and have them make a pinching hold with their fingers. Grab a hold of the ruler by pinching it on the short side near the 30 cm mark and hold it upright such that the 0 cm end is just between your friend’s fingers.

Tell your friend that when they see you release the ruler, they are to pinch shut and grab it as fast as possible. Try not to make any sounds, gestures, or other hints that you are releasing the ruler. They have to react to the visual stimulus of seeing the ruler being released. Record the centimeter mark where they pinched the ruler, and repeat this a few times.

Once you have the measurements, we just need to do some math. The formula below consists of three variables: y = the distance you measured in centimeters; g0 = the acceleration due to gravity constant (981 cm/sec2); and t = time in seconds.

Since we are looking for the time (t), we can rearrange the equation using some algebra to look like:

Let’s do some math.

How fast was your friend? The typical reaction time of humans is between 0.15s and 0.3s. In the 2016 Olympic Games, Usain Bolt had a reaction time of 0.155s.

Excerpted from How Your Brain Works by Greg Gage and Tim Marzullo. Copyright © 2022 by the MIT Press. All rights reserved. 

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