Human reaction time: practical | Biology | Quizalize & Oak National Academy

Starter quiz

If an insect flies towards our eye, we blink to protect our eye. Which common life processes enable us to react in this way?

excretion

growth

movement ✓

reproduction

sensitivity ✓
The ______ system of the human body enables us to detect and react to changes in our internal or external environment.

'nervous' ✓
A change in our environment that is detected by our nervous system is called __________.

an effector

a receptor

a response

a stimulus ✓
The eye contains sensory __________ that detect light. This enables us to see an insect flying towards us.

detectors

receptors ✓

reactors

stimuli
When sensory receptors in the eye detect light, they transmit impulses along sensory ______ in the peripheral nervous system.

'neurones' ✓
We blink in response to an insect flying towards our eye. Match each keyword to the correct structure.

effector

⇔

Muscles in the eyelid that contract to make us blink. ✓

motor neurone

⇔

Nerve cell that transmits impulses from the CNS to the eye. ✓

spinal cord

⇔

Structure in CNS, receives nerve impulses from receptors in the eye. ✓

Exit quiz

What is the correct definition of reaction time?

The time taken for a nerve impulse to travel along a motor neurone.

The time taken for a nerve impulse to travel along a sensory neurone.

The time taken for a stimulus to be detected by receptors.

The time taken to react to a stimulus. ✓
Some students plan investigations into reaction time in a human participant. Whose investigation would be considered ethical?

Andeep: Poke them with a sharp pin and time their reaction to the pain.

Izzy: Time how long it takes for them to say “on” when a lamp is switched on. ✓

Jun: Compare their reaction times before and after eating a large dose of sugar.
Put the method steps in order to describe how to measure the reaction time of a test subject using the ruler drop test.

1

⇔

Hold ruler with the 0 cm end aligned with the subject’s thumb and forefinger.

2

⇔

Without any countdown, let go of the ruler.

3

⇔

The subject must catch the ruler as quickly as they can.

4

⇔

Record the distance at which the ruler was caught.
The ruler drop test can be used to investigate reaction time. In one test, the person catches the ruler at a distance of 33 cm. Use the table to convert this result to a reaction time.

'0.26' ✓
The test subject caught the ruler at 52 cm with their left hand, and at 59 cm with their right hand. Which hand had the fastest reaction time?

Both hands had the same reaction time.

The left hand had the fastest reaction time. ✓

The right hand had the fastest reaction time.
The test subject caught the ruler at 52 cm with their left hand, and at 59 cm with their right hand. What can you conclude about whether they are left-handed or right-handed?

It’s not possible to conclude this from the results.

The left hand appears to be their dominant hand. ✓

The right hand appears to be their dominant hand.

Worksheet

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Lesson Details

Key learning points

Some factors affect human reaction time (e.g. the time taken to catch a ruler after it is dropped).
Writing a testable prediction or hypothesis about the effect of a factor on human reaction time.
Identifying independent and dependent variables, range of values to test, and which factors to control and how.
Safe use of apparatus, and safe and ethical use of human test subjects.
Interpret data from measurements of human reaction time.

Common misconception

Describing and identifying independent, dependent and control variables and following a method with care and accuracy are skills that take time to build and need frequent revisiting.

The variables in the practical and the method are outlined and discussed. Considerations on the ethicality of the experiment due to human subjects, and the presence of anomalous data, are also covered in detail.

Keywords

Reaction time - The time taken to react to an event.
Ethical - Something that is morally good and does no harm.
Variable - Something that can be changed, measured or controlled in an experiment.
Prediction - A scientific prediction is a testable statement about a possible outcome of an experiment.