Experiment: How Fast Your Brain Reacts To Stimuli
How fast do you think you are? Do you know what a reflex and a reaction are? This lesson plan tells all about the quickness of your nervous system and the muscular system, which the nervous system innervates.
What will you learn?
In this experiment you are going to be introduced to what a reflex and reaction are and how we go about measuring them. Do not worry we won't be throwing soccer balls at your face. . . yet!
Note: Backyard Brains has released a digital reaction timer that uses your body's electrical signals to measure your reaction time! If you enjoy this experiment and want to take it to the next level, check out the Backyard Brains Reaction Timer!
The speed of your reactions play a large part in your everyday life. Fast reaction times can produce big rewards, for example, like saving a blistering soccer ball from entering the goal. Slow reaction times may come with consequences.
Reaction time is a measure of the quickness an organism responds to some sort of stimulus. You also have "reflexes" too. Reflexes and reactions, while seeming similar, are quite different. Reflexes are involuntary, used to protect the body, and are faster than a reaction. Reflexes are usually a negative feedback loop and act to help return the body to its normal functioning stability, or homeostasis. The classic example of a reflex is one you have seen at your doctor's office: the patellar reflex.
This reflex is called a stretch reflex and is initiated by tapping the tendon below the patella, or kneecap. It was first independently described in 1875 by two German neurologists, Wilhelm Heinrich Erb and Carl Friedrich Otto Westphal. In their original papers Erb referred to the reflex as the "Patellarsehnenreflex" while Westphal denoted it as the "Unterschenkelphanomen". Thankfully, we now refer to it as the patellar reflex.
This reflex is also known as a "reflex arc". It is a negative feedback circuit that is comprised of three main components: