AuthorDawson, Spencer Charles
AdvisorAllen, John J.B.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractPeople with insomnia overestimate how long it takes to fall asleep and underestimate the total amount of sleep they attain. While memory is normally decreased prior to sleep onset, this decrease is smaller in insomnia. Insomnia generally and the phenomena of underestimation of sleep and greater memory prior to sleep area associated with arousal including cortical, autonomic, and cognitive arousal. The goal of the present study was to simultaneously examine arousal across these domains in relation to memory and accuracy of sleep estimation. Forty healthy adults completed baseline measures of sleep, psychopathology, and memory, then maintained a regular sleep schedule for three nights at home before spending a night in the sleep laboratory. On the night of the sleep laboratory study, participants completed measures of cognitive arousal, were allowed to sleep until five minutes of contiguous stage N2 sleep in the third NREM period. They were then awoken and asked to remain awake for fifteen minutes, after which they were allowed to resume sleeping. For the entire duration that they were awake, auditory stimuli (recordings of words) were presented at a rate of one word per 30 seconds. Participants slept until morning, estimated how long they were awake and then completed memory testing, indicating whether they remembered hearing each of the words previously presented along with an equal number of matched distracter words. Memory was greatest for words presented early in the awakening, followed by the middle and end of the awakening. High cortical arousal prior to being awoken was associated with better memory, particularly for the early part of the awakening. High autonomic arousal was associated with better memory for the late part of the awakening. Cognitive arousal was not associated with memory. Longer duration of sleep prior to being awoken was associated with better memory for the middle of the awakening. Better memory at baseline was associated with better memory, specifically in the middle of the awakening. Contrary to expectation, memory for the awakening was not associated with accuracy of the perceived length of the awakening. The present study found complementary associations between cortical and autonomic arousal and memory for an awakening from sleep. This suggests that decreasing arousal in both domains may reduce the discrepancy between subjective and objective sleep in insomnia. This also suggests the initial magnitude of decrements in cognitive performance after being awoken are related to deeper proximal sleep initially, while speed of improvement in cognitive performance is related to longer prior sleep duration.
Degree ProgramGraduate College