Author: Maddie Van Beek

Most of the time, people don’t associate video game players or “gamers” with sports, but do you think that your time spent playing video games might improve your reaction time? Having a good reaction time is definitely a part of being a good athlete! For example, a baseball player must react quickly in order to hit a fastball!



Can you react quickly enough to hit a 90mph fastball?
https://www.exploratorium.edu/baseball/reactiontime.html


How can you test this theory out? Before we get experimenting, let’s learn a little more about reaction time.


In simple terms, a reaction is when you detect something, process it, and respond.

​Basically, reaction time is how it takes one to respond and make a decision to a stimulus.

​A stimulus is any change inside or outside the body. In response to any stimulus, the following happens:



Sensory neurons detect the stimulus ----> Sensory neurons send the message to other neurons, which go to your brain and spinal cord ----> Brain interprets the message ----> Message received by motor neurons ----> Motor neurons tell muscles how to respond



Now that you know a little science behind reaction time, let’s get testing!


YOU WILL NEED:
* Meter stick
* “Gamers” to test
* “Non-gamers” to test
* Table or countertop

Here’s what to do!
1. Test yourself. Sit down at a table or counter with your arm resting on the surface. Your hand should be just off the edge of the counter.

2. Have a friend hold the meter stick so the end that says 0 is right in between your thumb and forefinger. View the image above for reference.

3. Have your friend drop the stick. Pinch the stick as quickly as you can. Record the number that your thumb/forefinger is closest to. The lower the number, the better your reaction time. Do this two more times and record your reactions.

4. Add all three reactions together and then divide by 3 to get your average reaction. For example, if you got 8 cm, 4 cm, and 7 cm, you would add them together first. 8 cm + 4 cm + 7 cm = 19 cm Then you divide the sum by three to get your average. Round to the nearest tenth of a centimeter. 19 cm / 3 = 6.33 cm

5. Once you’ve tested yourself, find your subjects! You should have an equal number of gamers and non-gamers. Shoot for ten total subjects or more. The more subjects you have, the more accurate your results will be.
6. Repeat steps 1-4 for each subject.
7. Analyze your results. Does it appear that gamers have quicker reaction times than non-gamers?
8. Find the average reaction time for each group. Do this by adding together the average reactions of each non-gamer and then dividing by the number of non-gamers. Do the same for the gamers. Compare averages.


Alternatively or in addition, you could try out this computer-run reaction test: http://www.humanbenchmark.com/tests/reactiontime


If you decide to use the computer test, make sure you have good internet connection and use the same computer and mouse for each subject.


Extension: Test other subject groups that might have differences in reaction time. Example: Contact sports players vs. Runners


For other experiments that test the brain, check out:

http://www.discoveryexpresskids.com/blog/mind-games-how-optical-illusions-can-fool-your-brain
http://www.discoveryexpresskids.com/blog/are-you-right-side-dominant-or-left-side-dominant-find-out
http://www.discoveryexpresskids.com/blog/how-does-smell-affect-your-taste
http://www.discoveryexpresskids.com/blog/remember-this-test-your-memory


If you’re looking for activities that get you active, check out:

http://www.discoveryexpresskids.com/blog/running-for-your-heart
http://www.discoveryexpresskids.com/blog/how-physically-fit-are-you
http://www.discoveryexpresskids.com/blog/why-is-heart-health-so-important


References
http://www.sciencebuddies.org/science-fair-projects/project_ideas/Sports_p009.shtml#summary
http://www.scientificamerican.com/article/bring-science-home-reaction-time/
http://slideplayer.com/slide/4497621/

Do you need to wear glasses?  If you do, things probably look a little fuzzy when you take your glasses off.  If you don’t, you’re lucky!  But why do some people need to wear glasses, while others don’t?  What makes the eyes of these people different?

First, let’s take a look at how our eyes work.  The eye is basically a ball filled with a jelly-like substance called the vitreous humor.  At the front of your eye (the part you can see when you look in the mirror) is a thin, rounded dome of tissue called the cornea; this is like a window that lets light pass through the eye.  Once past the cornea, the light passes through the pupil (the black part of your eye), an opening surrounded by the iris (the colored part of your eye).  Inside the pupil is the lens, which focuses the entering light on the tissues at the back of your eye which are called the retina.  The retina turns the light into an electrical signal, which is transmitted by the optic nerve to the brain; the brain then interprets these electrical signals, allowing us to see all the things around us.

So what’s happening if things look blurry to you without glasses?  It depends on which things you see as being blurry.  If you see things far away from you as blurry, but things close to you are in focus, you are nearsighted.  Nearsightedness (or myopia) is generally caused by one of two things: either the eye itself has become too long, causing the focus of the light to fall in front of the retina; or the lens or cornea has become excessively curved, and so does not focus the light at the appropriate distance.  If you are nearsighted, your glasses have concave lenses—that is, they are thinner in the middle than at the edges.  This helps the light focus on the retina as it should.

If you see things near you as blurry, but things far away from you are in focus, you are farsighted.  Farsightedness (or hyperopia) is generally caused by one of two things:  the eye itself has become too short, causing focus of the light to fall behind the retina; or the lens or cornea is less curved than it should be, and so does not focus the light at the appropriate distance.  If you are farsighted, your glasses have convex lenses—that is, they are thicker in the middle than at the edges. 

So how can you tell how good your eyesight is?  One of the easiest and most popular tests of eyesight is called a Snellen Chart (named after Dr. Hermann Snellen who invented it in 1862 (1)). 

This chart is usually hung on a wall, and the person being tested stands 20 feet away.  They try to read as many of the letters in the chart as they can, covering up first one eye, and then the other.  If you can read the eighth row of letters without glasses, you have 20/20 (normal) vision.  If you can only read down to the fifth line without making mistakes, you have 20/50 vision—this means you can see at 20 feet away what a person  with normal vision could see at 50 feet away (2).  This is also called your visual acuity.  If you cannot even see the first letter at the top of the chart, you are considered legally blind!

TEST YOUR EYESIGHT!

NOTE: While this is an easy and usually accurate way to test your eyesight, it is NOT a substitute for getting your eyes checked by a professional!  Only an eye doctor can provide you with the correct prescription for glasses, or diagnose if you have any other problems with your eyes.

Here’s what you’ll need:

1.       Masking tape

2.       A tape measure at least 20 feet long

3.       An accurate Snellen Chart, which you can download and print by clicking here, or go to http://www.i-see.org/block_letter_eye_chart.pdf.

4.       A friend to help you

 

Here’s what to do:

1.       Download and print the Snellen Chart from the link above.  Be sure to disable the printer’s “Fit to Page” option.  The first page contains instructions, the last page we’ll get to later!

2.       Check t o be sure the chart has printed correctly—the letter ‘E’ at the top of the chart should be 3.49 inches (88.7 millimeters) high.

3.       Tape the chart on a wall at eye level, with the largest letter at the top.

4.       Measure 20 feet from the wall using your tape measure, and mark that spot with masking tape.

5.       First cover your left eye, and read the numbers on the chart aloud, starting at the top and reading every line until the letters are too small for you to read.  Have your friend keep track of which line you could not read.

6.       Now cover your right eye, and repeat step 5 with your left eye.

7.       When you have finished, ask your friend which lines were the smallest you could read. 

8.       To calculate your visual acuity for each eye, take the number to the left of the smallest print you could read for that eye, and put it under the number 20.  For instance, if the smallest line you could read was the seventh line from the top letter, your vision in that eye is 20/30—you can see at 30 feet what a person with normal vision can see at 20 feet. 

What is your visual acuity?  Do you wear glasses?  Do you think you should?  If you think you may need glasses, visit an eye doctor to have your eyes professionally checked!


MORE THINGS TO TRY!

The final page of the eye chart is called a Near Vision Test Card, and it tests how good your vision is close up.  Tape this page to a wall and stand 16 inches away, and see how many rows of letters you can read!

If you do need glasses, and you are nearsighted, here’s a really cool trick to try! 

Take a piece of paper (any piece large enough to cover your eye will do), and poke a small hole in it with a pen. 

Close one eye, and hold the paper up to your open eye. 

Look at something far away through the tiny hole in the paper.  Does it look more focused?


References for further reading:

1.       H. Snellen, Probebuchstaben zur Bestimmung der Sehschärfe, Utrecht 1862.

2.       "What Does 20/20 Vision Mean?"  Eye Care Associates of East Texas. http://www.eyecaretyler.com/2020.htm.  Accessed 28 May 2014.

With the Super Bowl airing today, and the Olympics starting on February 7 (next
Friday), there will soon be many highly fit individuals running, jumping, and
skiing their way across our television sets!  While I will certainly never be as
physically fit as an Olympic figure skater or skier, I would hope to achieve at
least an acceptable level for the average person. This brings up a
question...what exactly does it mean to be “physically fit”? 

By definition, physical fitness is, “a general state of health and well-being or specifically the ability to perform aspects of sports or occupations” (from the Wikipedia website on Physical Fitness).  So in general, to be physically fit means you should be able to perform your daily duties and actions without much difficulty and without getting too tired.  A person who has poor physical fitness will become tired from simple activities, such as climbing a staircase or walking from one room to another.  This can be due to several causes, such as poor diet, low physical activity, obesity (excess body fat), or a heart condition.  
 
What makes a fit person’s body so different from that of an unfit person?  First, if a person is in better physical condition they will tend to have less body fat than a person who is in poor physical condition, and so will have less weight to move around during physical activity.  A lighter body will put less stress on their bones and joints, too. In addition, there are some differences between the bodies of a person in good physical condition and a person in poor condition which may not be so obvious.  These include cardiovascular and muscular fitness.

When a person is in good cardiovascular condition (that is, their heart and lungs are in good condition), the volume of blood their heart is able to pump with each beat increases, and so does the amount of blood in their body.  This means that every time their heart beats, more blood is carried to their muscles, bringing oxygen and nutrients and carrying away waste more efficiently.  This means that their heart will have to beat more slowly when they are at rest, and that it will return to resting rate more quickly after exercise,
because they can supply their bodies with oxygen and nutrients (and get it to return to normal) with fewer beats per minute. 

Think of a person’s body as a city, and their cardiovascular system as the streets and highways carrying people around to all the organs and tissues.  If a person is in good cardiovascular condition, their city streets and highways are wider and well maintained, and so more cars can get where they need to go faster.  If they are in poor cardiovascular condition however, the streets and highways are
narrow, and can carry fewer cars at one time.

When a person’s muscles are in good condition, the muscles have more fibers and more blood vessels, and can therefore supply more power.  Think of the muscles as like ropes or cables that move our bodies: if the ropes are bigger and have more fibers (that is, more fibers that make up the rope), they will be able to
lift and pull larger amounts of weight.  The added blood vessels allow more oxygen and nutrients to flow to the muscles too, allowing them to work more efficiently (like the wider streets and highways in our last example).  

So how can we measure just how physically fit we are?  Through a series of tests measuring
your heart rate in number of beats per minute, we can get a good idea of just how fit you are.


TRY IT!


Here’s what you’ll need:


1.   A stopwatch or a watch with a sweep second hand

2.   A clean table you can lie down on or a clean towel to lie down on the floor

3.   Enough space to jog in place


Here’s what to do:


First, measure your standing heart rate.

1.   Stand upright for 2 minutes.  Be sure to stand still!

2.   With your index and middle finger, find the pulse at your wrist or your neck below your jaw bone.

3.   Count the number of times you feel your heart beat in 15 seconds.  Time this with your watch or stopwatch, and write down the number of beats.

4.   Multiply this number by 4 to get the number of beats per minute.

5.   Find the number of beats per minute in Table 1 below, and record how many points you earned.  Be sure to write this down!

 Next, measure your resting heart rate.

5.   Lie down on the table or the floor on a clean towel for 2 minutes.

6.   Record your heart rate as you did for your standing heart rate by repeating steps 2-4 above.

7.   Find the number of beats per minute in Table 2 below, and record how many points you earned.  Be sure to write this down!

Finally, measure your heart rate just after exercise, and how long it takes to return to normal.

8.   Jog in place for 10 seconds.  Time this with your watch or stopwatch.

9.   As soon as you stop, immediately begin recording how many times you feel your heart beat in 15 seconds.  Write this number down.

10.  Continue recording how many times your heart beats every 15 seconds until the number is the same as when you took your standing heart rate in step 3.  Write each number down.

11.  Count how many numbers you had to write down, and divide that number by 4.  This is how many minutes it took for your heart rate to return to the normal standing rate. 

12.  Multiply the first number you wrote down immediately after exercise by 4 to get beats per minute.  Be sure to write this down!

13.  Find the number of minutes it took for your heart rate to return to normal in Table 3 below, and record how many points you earned. Be sure to write this down!  If it took longer than 2 minutes, give
yourself 6 points.

14.  Subtract your standing heart rate from your heart rate just after exercise.  This is your heart rate
increase after exercise.

15.  Finally, in Table 4 below, find your standing heart rate on the left, and use the heart rate increase after exercise value on the top to find your points.  Write this down!

16.  Add up all the points you earned (steps 5, 7, 13, and 15).  Use the scale below to determine your level of fitness.

 
Are you as fit as you thought?  If you are not, why do you believe that is?  Do you need to get more exercise, or eat healthier?  
 
If you are not as fit as you want, try increasing your physical activity over the next few weeks, and repeat the test in one month.  See if you can improve your fitness level!



References for more information:


CDC: Physiological Responses and Long-Term Adaptations to Exercise
(http://www.cdc.gov/nccdphp/sgr/pdf/chap3.pdf)


Vernier Software and Technology website
(http://www2.vernier.com/sample_labs/BWV-27-COMP-heart_rate_physical_fitness.pdf)

Wikipedia: Physical Fitness (http://en.wikipedia.org/wiki/Physical_fitness)