Vigilance: discussion of related concepts and proposal for a definition

Abstract We reviewed current definitions of vigilance to propose a definition, applicable in sleep medicine. As previous contained terms such as attention, alertness, and arousal, we addressed these concepts too. defined alertness quantitative measure the mind state governing sensitivity stimuli. Arousal comprises stimulus-induced upward change irrespective subsequent duration increased level alertness. Vigilance is capability be sensitive potential changes one's environment, ie reach above threshold for certain period time rather than itself. It has temporal dimensions. Attention adds direction towards stimulus requiring cognitive control: it involves being prepared process stimuli coming from an expected direction. Sustained attention corresponds which some purposefully maintained, adding factor definition attention. differs sustained that latter addition implies cognitively directed well specification duration. Attempts vigilance, however, are often fact measurements