Effects of Total Sleep Loss on Sleep Tendency

TLDR

Six young adults underwent two consecutive nights of total sleep loss while daytime sleep tendency was objectively measured every two hours using the Sleep Latency Test. During the sleep‑loss period participants exhibited marked declines in cognitive performance (Wilkinson Addition and Serial Alternation tasks), increased subjective sleepiness and negative mood, and sleep latency test scores fell to ~1 min and remained low until after two recovery nights, with performance and sleepiness recovering after one or two nights of sleep.

Abstract

Effects of two nights of sleep loss were assessed in six young adult (18—21 yr.) volunteers (2 women, 4 men). Performance on the Wilkinson Addition Test fell significantly below baseline values during the sleep-loss procedure and recovered after one or two full nights of sleep. Performance on a Serial Alternation Task also declined during sleep loss. Mood and sleepiness, assessed by subjective self-rating scales, showed a significantly less positive mood and a greater degree of sleepiness during sleep loss, with a recovery to baseline levels after one full night of sleep. Sleep tendency, measured at 2-hr. intervals during all waking periods, was assessed using an objective measure of latency to sleep onset, the Sleep Latency Test. The scores fell to about 1 min. at 0600 on the first night of sleep loss and remained at similarly low values Throughout the sleep loss period. After one night of recovery sleep the scores remained significantly below baseline levels, which were not achieved until after the second recovery night. The multiple sleep latency test appears to be a valuable operationally defined tool for measuring daytime sleepiness.