Performance and Mood Following Variations in the Length and Timing of Sleep

ABSTRACT The relative effects of extended sleep, sleep deprivation, and shifts of accustomed sleep time on subsequent performance and mood were studied. Ten regular 2400–0800 sleepers worked on E‐paced addition and vigilance tasks, and completed an adjective check list to rate their mood following 2100‐0800 extended, 2100‐0500 advanced‐shift, 2400‐0800 habitual, 0300‐0800 deprivation, and 0300‐1100 delayed‐shift conditions of sleep. Accuracy and speed of response on the vigilance task were significantly poorer, and negative affect was significantly greater after the conditions of shifted sleep and altered sleep duration than after the habitual sleep condition. Changes in the mood and performance measures were unrelated to prior sleep length or any specific alterations in the electrophysiological patterns of sleep.