Measuring Reaction Time Practical

Learning Objectives

• Understand how to measure a person's reaction time.
• Familiarize with the details of the practical experiment.

Experiment Method

Participants

• Requires two people: Person 1 (subject) and Person 2 (tester).

Setup

1. Positioning:

   • Person 1 sits on a stool with good upright posture.
   • Place the forearm of the dominant arm across the table, with the hand overhanging the edge.
   • For right-handed individuals, the dominant arm is the right arm.

2. Ruler Drop Test:

   • Person 2 holds a ruler vertically with the 0 cm mark between Person 1's thumb and first finger.
   • Person 2 instructs Person 1 to prepare for the catch.
   • At a random time, Person 2 drops the ruler.
   • Person 1 catches the ruler with their thumb and first finger as quickly as possible.
   • Person 2 records the measurement on the ruler at the level of the top of Person 1's thumb.

3. Repetition:

   • Person 1 has a short rest.
   • Repeat the test several times to calculate a mean reaction time.
   • Afterward, switch roles to measure Person 2's reaction time.

Variables

Independent Variable

• The person having their reaction time tested (Person 1 or Person 2).

Dependent Variable

• The measured reaction time.

Control Variables

• Starting distance between thumb and first finger must remain constant.
• Always measure the ruler at the top of the thumb.
• Keep conditions in the room consistent (lighting, background noise).

Additional Investigations

• Investigate various factors affecting reaction time:
  • Practice Effects: Catching the ruler multiple times to see if reaction time improves.
  • Dominant vs Non-Dominant Hand: Test reaction time with both hands to compare results.
  • Chemical Effects: Examine the impact of caffeine by having the test subject drink cola before testing, while controlling for other chemicals by using caffeine-free cola as a comparison.

Safety Considerations

• Check for any medical issues (e.g., allergies, heart conditions) before administering caffeine.
• Conduct tests in a lab where hazardous chemicals are not present.

Additional Resources

• Questions on this practical can be found in the vision workbook linked in the video.