Cognitive Performance, Circadian Rhythms and Circadian Type

The body's 24-hour clocks regulate when we feel sleepy or alert. In shift workers, these biological clocks become misaligned due to sleep and wake which occurs in opposition to the light-dark cycle. Misaligned rhythms lead to reduced cognitive performance and increased fatigue, which can result in significant workplace accidents. Some individuals adapt to shift work better than others, though the mechanisms driving this individual difference are not well known. Subjective assessments of Circadian Type may be one way of identifying an individual's propensity to adapt to shift work, and may me a cost-effective way to assess the biological rhythms that regulate the circadian system.