This thesis covers several steps in the process of validating the Sustained Attention to Response Task as a measure of vigilance in patients with excessive daytime sleepiness. It comprises a review... Show moreThis thesis covers several steps in the process of validating the Sustained Attention to Response Task as a measure of vigilance in patients with excessive daytime sleepiness. It comprises a review of the currently circulation definitions of vigilance and a proposal for a covering definition; an extension of previous vigilance measurements in narcolepsy and other patient groups with excessive daytime sleepiness; an assessment of factors possibly influencing SART results, such as task repetition, napping, time of day, and test instruction; and the value of the SART as a treatment efficacy measure in narcolepsy and obstructive sleep apnoea. Show less
We reviewed current definitions of vigilance to propose a definition, applicable in sleep medicine. As previous definitions contained terms such as attention, alertness, and arousal, we addressed... Show moreWe reviewed current definitions of vigilance to propose a definition, applicable in sleep medicine. As previous definitions contained terms such as attention, alertness, and arousal, we addressed these concepts too. We defined alertness as a quantitative measure of the mind state governing sensitivity to stimuli. Arousal comprises a stimulus-induced upward change in alertness, irrespective of the subsequent duration of the increased level of alertness. Vigilance is defined as the capability to be sensitive to potential changes in one's environment, ie the capability to reach a level of alertness above a threshold for a certain period of time rather than the state of alertness itself. It has quantitative and temporal dimensions. Attention adds direction towards a stimulus to alertness, requiring cognitive control: it involves being prepared to process stimuli coming from an expected direction. Sustained attention corresponds to a state in which some level of attention is purposefully maintained, adding a time factor to the definition of attention. Vigilance differs from sustained attention in that the latter in addition implies a direction to which attention is cognitively directed as well as a specification of duration. Attempts to measure vigilance, however, are often in fact measurements of sustained attention. (C) 2021 The Authors. Published by Elsevier B.V. Show less
