The effect of changing the intensity of a visual stimulus on reaction time was studied in 173 psychology undergraduates. This topic has proven beneficial to many worldwide implications, e.g. road safety. Each participant completed a computer-based task whereby they were to respond as quickly as possible to the appearance of either a light grey or dark grey circle against a black background. The number of participants with quicker response times to the more intense visual stimulus was significantly higher than any other proportion in the sample (p
