Biology - 10 The Human Nervous System - Required Practical 7: Reaction Time

Aims:

  • plan and carry out an investigation into the effect of a factor on human reaction time

Risk Assessment:

  • a laboratory may contain dangerous chemicals or apparatus

Safety:

  • use a space that is not used for dangerous chemicals

  • move away any dangerous or delicate apparatus

Equipment:

  • at least 2 people

  • metre rule

  • chair

  • table

Control variables:

  • starting distance between thumb and forefinger

  • measuring from the top of the thumb

  • conditions in room (e.g. lighting, noise)

Independent variable:

  • the person being tested

  • the state of the person being tested e.g.:

    • caffeine

    • sugar

    • practice

    • hand used

Dependent variable:

  • reaction time

Method:

  1. Person A sits on the chair with the forearm of their dominant arm overhanging the edge of the table

  2. Person B holds the metre rule suspended between person A’s thumb and forefinger. Person A is told the ruler will be dropped. Person B then drops the ruler at a random time, and person A must catch it as quick as possible

  3. The length of ruler that fell is measured from the top of the thumb and converted to a reaction time using a conversion chart

  4. Repeat steps 1 - 3 roughly 10 times and find the mean

  5. (OPTIONAL) Change the condition of person A with

    • caffeine

    • sugar

    • practice

    • hand used

  6. Repeat steps 1 - 4 and compare the two means to see the effect of the factor

Calculations/graphing:

n/a