The visual system is sensitive to sudden change. If something distracting occurs while a person is performing a task—reading a newspaper, for example—this immediately captures one's attention. This sudden shift can be a distraction but it has been also thought to be a reflex of great importance as identifying and reacting to environmental changes quickly (when needed) can be imperative to survival. Saccadic latency, the time delay between the appearance of a target and the initiation of a saccade, is an important parameter for learning which occulomotor neurons and structures of the brain play what specific roles in saccade initiation. There is much research being conducted on the role of SEF in determining visually salient objects and occurrences, using saccadic latency as the parameter of interest.