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