Slides in this set

Slide 1

Preview of page 1

lo g i c a l
o f B io
ru p t i o n
D i s
th m s
o r K h an
By Mahno…read more

Slide 2

Preview of page 2

Shift Work & Shift lag
· Night workers are awake during the night, therefore sleep through most
of the day
· They often experience a circadian "Trough" of decreased alertness,
between midnight as cortisol levels are lowest, and at 4.00am where core
body temperature is lowest
· They often experience sleep problems because they finish work daytime
and external zeitgebers such as noise & light disrupt the quality of their
sleep. Also daytime sleep is usually 2/3 hours less than nocturnal sleep
period. REM sleep is affected as a consequence . This poor quality sleep
means they find it hard staying awake at night.
· Knutsson et al (1986) found individuals who worked more than 15yrs of
shift work were 3x more likely to develop Heart disease
· Martino et al ­ there is a link between shift work and organ disease…read more

Slide 3

Preview of page 3

· Shift work may also be linked to lack of sleep as a result of sleeping at unusual times
· Another reason may be due to social disruption as it is difficult to meet friends and
spend time with family when working on a shift-divorce rates amongst all night-shift
workers, is a high as 60%
· Research suggests rotating shifts are more harmful to the biological rhythms. Gold et al
found fluctuating shifts are less disruptive, as the individual gets used to the pattern
· Bambra et al (2008)- Following a logical shift pattern may be less damaging on the body
e.g. one week ­ shift in morning, second week- shift in afternoon, third week- shift at
night . Also rotating workers though shift e.g. every 3 to 4 days is better for health and
work life balance
· Artificial light- important in resetting the rhythm . Boivin et al- found exposure to very
bright light can advance the biological rhythm. Gronfier et al (2007) were able to
synchronize circadian rhythms longer than 24 hours through bright light pulses.…read more

Slide 4

Preview of page 4

· Herxheimer and Petrie (2001)- found where melatonin (a
hormone which induces sleep) was taken near to bed
time, it was effective in inducing sleep, however if it
was taken at the wrong time of the day it ,may delay
· Social customs synchronize biological rhythms , e.g.
when travelling it is vital to eat and sleep at the right
time .
· Fuller et al (2008)-Research suggests by fasting and
eating on a new tome schedule may actual synchronize
biological rhythms. Because food acts as an exogenous…read more

Slide 5

Preview of page 5

· Moore-Ede estimated that it has cost the US
$77 Billion , due to major accidents e.g. lorry
accidents , occurring from shift work. Therefore
research on Shiftwork and its effects on the
biological rhythm are important in advancing
new techniques to minimize such incidents e.g.
rotating shifts…read more

Slide 6

Preview of page 6

Jet travel & Jet lag
· Jet lag- physiological effects of disruption of circadian rhythms , characterized by
loss of appetite, nausea, fatigue, disorientation , insomnia or mild depression
· Our Biological rhythms are not able to cope with sudden or large changes
· The dorsal section of the Suprachiasmatic Nucleus takes several cycles to
resynchronize to abrupt changes in environmental changes, this is known as Jet lag
· Winter et al (2008)- found that this is equivalent to 1 day to adjust each hour of time
· Retch et al (1995)- Studied US baseball results over a 3 year period- Teams who
travelled east to west (phase delay) won an average of 44% of their games,
compared to teams travelling west to east (phase advance) only won 37% of games…read more

Slide 7

Preview of page 7
Preview of page 7


No comments have yet been made

Similar Psychology resources:

See all Psychology resources »