Inducing jet lag in the laboratory: patterns of adjustment to an acute shift in routine.
Eight middle-aged males were studied in a temporal isolation experimental lasting 15 d. After 5 d and nights of entrainment to his own habitual routine, each subject experienced an acute, unheralded 6-h phase advance in routine, accomplished by truncating his sixth sleep episode. For the remaining 10 d of the study, subjects were held to a routine 6-h phase advanced to the original. Significant symptoms of jet lag appeared in mood, performance efficiency, sleep, and circadian temperature rhythms. When plotted as a function to "days post-shift," some variables (temperature phase, percent rapid eye movement sleep) showed a fairly monotonic recovery to baseline levels. However, other variables (actual sleep duration, percent slow wave sleep, motivation loss, subjective sleepiness) showed a zig-zag recovery pattern, suggesting the interaction of two competing processes, and reinforcing the need for greater sophistication in the development of jet lag coping strategies.
Monk
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Sleep Evaluation Center, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, PA 15213.
Moline
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Graeber
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D000328:Adult; D000339:Affect; D001831:Body Temperature; D002940:Circadian Rhythm; D006801:Humans; D008297:Male; D008875:Middle Aged; D012107:Research Design; D012890:Sleep / Q000502:physiology; D012892:Sleep Deprivation / Q000502:physiology*; D013647:Task Performance and Analysis; D014195:Travel