Time estimation circadian rhythm in shift workers and diurnally active humans.

ABSTRACT

The ability of shift workers to estimate timer intervals of short duration was examined. The study included 22 shift workers and 10 diurnally working control subjects. A circadian rhythm in time estimates was documented in control subjects, but it was found to bed disrupted in shift workers. Spectral analysis revealed frequency or circadian component in time estimates to be lower among the shift workers. Furthermore, an interesting relationship was marked between time estimates and oral temperature in 4 control subjects and 6 shift workers in that the time of the closest estimation coincided with the peak time of their body temperature.