AQA GCSE Biology · 8461
Specification 4.5.2.1 · Paper 2
Revise: Investigating Factors Affecting Reaction TimeReaction time is the interval between a stimulus and a response. In a ruler-drop test, seeing the ruler begin to fall is the stimulus; closing the thumb and first finger around it is the response. Receptors in the eyes detect the movement, and the nervous system coordinates the hand muscles that catch the ruler.