Final answer:
The minimum amount of stimulus energy required to detect a given stimulus is called the absolute threshold.
Step-by-step explanation:
The minimum amount of stimulus energy required to detect a given stimulus is called the absolute threshold. It refers to the minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time. For example, the sensitivity of our sensory receptors allows us to detect a candle flame 30 miles away or the tick of a clock 20 feet away, under optimal conditions.