Response

The response is the action that follows. Human reaction time is the interval between the stimulus occurring and the person beginning their response. It includes the time needed to detect the change, process the information and initiate an action.

Human reaction time is the interval between a stimulus occurring and the start of a response. For example, the stimulus might be a ruler being released and the response might be the fingers closing to catch it. The delay exists because the stimulus must be detected, information must be processed and a response must be produced.