Investigating the Effect of Alcohol on Reaction Times

Investigating the effect of alcohol on reaction times

Setting the scene

Have you heard the slogan ‘don’t drink and drive’ before? In the UK, there are laws against people drinking alcohol and driving. If someone has been drinking alcohol they are more likely to have a road traffic accident.

In this investigation, you are going to compare the reaction times of people who haven’t been drinking alcohol (your class) with people who have been drinking alcohol, using secondary data.

Aims

In this practical you will:

§  investigate the cause of a drink-driving accident

§  compare reaction times of people who have drunk varying amounts of alcohol.

You will be working scientifically to:

§  make and record observations and evaluate the reliability of the method

§  present data using appropriate tables and graphs

§  interpret observations to identify patterns and draw conclusions.

Equipment and materials

§  metre ruler

§  graph paper

Prediction

Predict how the consumption of alcohol affects reaction times.

Method

1 Work in pairs for this experiment.

2 Use your right hand for this experiment if you are right-handed, and left hand if you are left-handed.

3 Position yourselves as in the image. The person standing up is the experimenter, and the one sitting down is the subject.

4 The subject sits sideways at the bench with their arm over the edge.

5 The experimenter should hold the metre ruler vertically between the subject’s first finger and thumb, with the zero opposite the thumb.

6 The experimenter should drop the ruler without warning.

7 The subject should catch the ruler between their thumb and finger as quickly as possible.

8 Record the catch distance to the nearest centimetre.

9 Record results in a suitable table.

10 Swap over so the subject now becomes the experimenter, and vice versa. Repeat the experiment.

11 Repeat twice per person.

Results

§  Design a suitable results table to record your results.

§  Include a final column for the average catch distance (cm).

§  Add rows to your table so that you can record results for you and five others in your class.

§  Don’t forget to include the units in your column headers.

Questions

1 Describe the link between catching distance and reaction time.

The police conducted an experiment to obtain similar data on catch distance for subjects who had drunk different amounts of alcohol in the hour before the test.

A large group of subjects was used for the sample group and the average catch distance was calculated. The data is shown below.

Calculate the average catch distance (cm) for the six results you have collected and complete the table below.

2 Plot a suitable graph to present the data above.

3 Describe the relationship between the units of alcohol consumed and catch distance.

4 Explain, using scientific knowledge, why alcohol has this effect on reaction times.

5 Use your answer to Question 4 to suggest a reason why people who have drunk alcohol are more likely to have a road traffic accident.

Extension

1 Suggest a reason why the police sample group contained a large number of people (100 in each category).

2 Currently, in the UK it is legal to drink one unit of alcohol and still drive. Using the information here, suggest a reason why one unit of alcohol is classed as legal.

© Oxford University Press 2014 www.oxfordsecondary.co.uk/acknowledgements

This resource sheet may have been changed from the original.