This requires the application of information from memory to interpret the sensory input. Response selection slows under choice reaction time when there are multiple possible signals. Conversely, practice decreases the required time. Once a response is selected, the responder must perform the required muscle movement. For example, it takes time to lift the foot off of the accelerator pedal, move it laterally to the brake and then to depress the pedal.
Several factors affect movement times.
In general, more complex the movements require longer movement times while practice lowers movement times. Finally the Yerkes-Dodson Law says that high emotional arousal, which may be created by emergency, speeds gross motor movements but impairs fine detailed movements. Time Mechanical devices take time to actuate, even after the responder has acted. For example, a driver stepping on the brake pedal does not stop the car immediately. Instead, the stopping is a function of physical forces, gravity and friction.