Disruption of Biological rhythms Flashcards
Shift work
Decreased altertness
Night workers often experience a trough of decreased alertness during their shifts, this occurs between 12am-4am when cortisol and temperature is lowest.
Shift work
Sleep deprivation
Workers who sleep during the day may experience sleep deprivation due to interruptions during the day. Day time sleep is reduced by 1-2 hours and REM is particularly affected. Making staying awake at night all the more harder
Shift work
Effects on health
It has been found that individuals who worked shifts for more than 15yrs are 3 times more likely to develop heart disease. Due to the effects of desynchronisation, shift work has been linked to a range of organ diseases.
Shift work
Evaluation
Shift work effects not just due to the disruption of biological rhythms.
The effects may be due to lack of sleep associated with going to sleep an unusual times.
Social disruption is a factor too, meeting and socialising is difficult,divorce rates may be as high as 60% among those as night-shift workers.
Shift work
Evaluation
Rotating shifts
Non-fluctuating shifts are less disruptive because you can get used to one sleep-wake cycle. More problems occur in those who partake in fluctuating shifts
Shift work
Evaluation
Are forward rotating shifts better?
Yes, they are better for the health of shift workers. An example of this is morning for 1 week, afternoon the next and night the next. Rotating workers through shift changed more quickly is better for health.
Jet lag
It is estimated that the dorsal portion of the SCN takes several cycles to fully synchronise. This is equivalent to one day to adjust to each hour of time change.
Jet lag
Performance decrement
American baseball teams when they have to travel from East to West (phase delay) play better than those who have to travel from West to East (phase advance) showing that phase advance has a greater influence on performance.
Jet lag
Evaluation
What else may jet lag be affected by?
Sleeping badly the night before travelling, travelling itself and holidays involving drinking alcohol or coffee, noise, annoying passengers can all contribute to jet lag.
Jet lag
Evaluation
Eating
Eating on the new time schedule can help entrain biological rhythms because our body clocks are reset by food intake.
Shift work
Evaluation
Individual differences
It was found that those who gave up shift work tended to have rhythms that changed a lot while those who were ‘happy shift-workers’ had unchanging rhythms.
Both
Real world application
Being able to find out the implications of shift work and jet lag may help avoid disasters
