(P) Investigating Reaction Time

• Reaction time is the time it takes to respond to a stimulus. It can be affected by factors such as age, gender, or drugs
• Caffeine is a drug that can speed up a person's reaction time. The effect of caffeine on reaction time can be measured
• 1. The person being tested should sit with their arm resting on the edge of a table (this should stop them moving their arm up and down durinig the test)
• 2) Hold a ruler vertically between their thumb and forefinger. Make sure that the zero end of the ruler is level with their thumb and finger. Then let go withought giving any warning
• 3) The person being tested should try to catch the ruler as quickly as they can - as soon as they see it fall
• 4)Reaction time is measured by the number on the ruler where it's caught. The number should be read from the top of the thumb. The further down the ruler it's caught (i.e. the higher the number), the slower their reaction time
• 5) Repeat the test several times then calculate the mean distance that the ruler fell
• 6) The person being tested should then have a caffeinated drink. After 10 minutes, repeat steps 1 to 5
• 7) You need to control any variables to make sure that this is a fair test. E.g., you should use the same person to catch the ruler each time, and that person should always use the same hand to catch the ruler. Also, the ruler should always be dropped from the same height, and you should make sure that the person being tested has not had any caffeine before the start of the experiment
• 8) Too much caffeine can cause unpleasant side-effects, so the person being tested should avoid drinking any more caffeine for the rest of the day after the experiment is completed