Sleepiness, alertness and performance during a laboratory simulation of an acute shift of the wake-sleep cycle.
Monitoring the presence of sleepiness on the job and its effects on performance is of primary importance for improving schedule systems of shiftworkers. Shiftworkers, often involved in night-time operations and irregular work schedules, frequently complain of nocturnal sleepiness especially in conditions of abrupt shift of the wake-sleep cycle. In this study, the authors evaluated the effects of a laboratory simulation of acute night-shift changes on sleepiness, vigilance and performance, using Maintenance of Wakefulness Test, Multiple Sleep Latency Test and three pencil and paper tests: Digit Symbol Substitution Test, 'Deux Barrages' Test and a 3-Letter Cancellation Task. All of the tests were administered four times at 2-hourly intervals during the night after daytime sleep. Results showed that the ability to maintain wakefulness and to perform simple visuo-attentive tasks is substantially spared during the night. On the other hand, sleep tendency and performance on a more complex and monotonous task (Letter Cancellation Task) reveal, respectively, increasing sleepiness and degrading performance.
Italian Air Force, DASRS-RMAS, Aeroporto Pratica di Mare, Pomezia, Rome, Italy.
S
S
Porcu
A
A
Bellatreccia
M
M
Ferrara
M
M
Casagrande
D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017286:Polysomnography; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012894:Sleep Stages / Q000502:physiology*; D013647:Task Performance and Analysis; D014851:Wakefulness / Q000502:physiology*; D014940:Work Schedule Tolerance / Q000502:physiology*