Disruption of Biological Rhythms


Environmental factors influencing biological rhythms tend to change slowly, allowing the internal pacemakers to keep up. However, if the zeitgebers change quickly, problems can occur. Such problems include poor attention, slow reaction time and impaired reasoning skills and can arise from two features of modern life; shift work and jet lag.





Shift working involves regular changes to the hours of work. This leads to impaired performance and potentially dangerous situations. Frequent shift changes (weekly) are the hardest to readjust to, so longer periods of readjustment (every three weeks) are better for the workforce and, consequently, production (Czeisler et al., 1982).






Jet lag occurs when flying to different time zones (particularly from West to East). The symptoms are thought to be caused by melatonin release being out of step with the new environmental conditions. This results in drowsiness during the day and insomnia at night. Evidence suggests that melatonin supplement pills taken in the evening may reduce the effects of jet lag (Blakemore, 1988).

Here is a summary of this Quick Learn. Drag and drop the terms so they have the correct definition: