Name 3 Psychologists who investigated the

effects of Shift Work?

(B, T&W, K)

Boivin et al.

Tilley & Wilkinson

Knuttsson et al.

How did Boivin  et al. investigate Shift Work?

Found that night workers often experience a Circadian 'trough' of decreased alertness. Cortisol levels are lowest after midnight when core body temperature is also low, which could explain this.

How did Tilley & Wilkinson investigate Shift work?

Found that Daytime sleep tends to be 1-2 hours shorter than nocturnal sleep, mainly due to the increased amount of interruptions during the day - such as noise. Poor daytime sleep also makes it more difficult for shift workers to then stay awake at night.

How did Knuttsson et al. investigate Shift work?

Found that individuals who had worked shifts for more than 15 years are 3 times more likely to develop heart disease than non-shift workers.

Name 2 Psychologists who investigated the

effects of Shift work?

(W, R)

Winter et al.

Recht et al.

How does the Dorsal SCN affect/cause

Jet Lag?

It takes several cycles to fully resynchronise to abrupt environmental changes.

How does Winter et al. investigate 

Jet Lag?

Calculated that it takes 1 day to adjust to each hour of time change.

What are some symptoms of Jet Lag?

Nausea, Disorientation, Fatigue, Loss of appetite, dizziness.

How did Recht et al. investigate

Jet Lag?

Analysed US baseball results over a 3 year period and found that teams which travelled east to west, performed better and won more of their games than those travelling west to east. This is due to 'phase delay' because it easy to stay up late than it is to get up earlier.

Name the 5 methods of 

treating Jet Lag?

(Initials: RS, FWS, AL, M, SC)

Rotating Shifts

Forward Rotating Shifts

Artificial Lighting

Melatonin

Social Customs

How might Rotating Shifts reduce the

harmful effects of Shift work/Jet Lag?

Non-changing shifts (eg. always working at night) has been proven to be less disruptive as it gives the individual time to adjust to a single unchanging pattern.

How might Forward-rotating shifts reduce

the harmful effects of Shift work/Jet Lag?

Follows the logical order of the day (phase delay) and so seems easier and is less harmful to the body. For example, a shift in the morning for one week, then a shift in the afternoon for one week followed by a shift at night for one week.

How might Artificial Lighting be used to reduce the

harmful effects of Shift work/Jet Lag?

Boivin et al. investigated whether artificial lighting could reset rhythms. He split male participants into four groups who were kept on inverted cycles (awake at night). Each group was exposed to varying degrees of brightness in artificial lighting. The group with the brightest light proved to advance hours earlier than all the others, which proves the effectiveness of using artificial lighting.

How might Melatonin be used to reduce the harmful

effects of Shift work/Jet Lag?

Taking melatonin before going to bed has been proven effective for helping individuals sleep as it is the natural hormone for inducing sleep.

How might Social Customs be used to reduce the

harmful effects of Shift work/Jet Lag?

Eating at the right times and sleep when the clocks says it is late, whilst in a new place with a different time zone can help adjust to a new rhythm as you are accepting external cues.

What are 2 IDA criticisms of research into

Shift work/Jet Lag?

(Initials: ID, LE)

Individual Differences

Lab experiments

Why might Individual Differences be an issue for 

research into Shift work/Jet Lag?

Research has shown that individuals whose rhythms change the least, cope better with shift work/jet lag. Thsoe whose rhythms are constantly changing, cannot adjust to a new rhythm and so cope less easy.

Why might the use of Lab experiments be an issue for

research into Shift work/Jet Lag?

Studies such as Boivin et al.'s are effective because it means that variables are controlled and so cause and effect is well demonstrated. However, this is also a weakness as it means the study lacks ecological validity as results may not be the same in real life.

Name the Psychologist who put forth the theory of

Rotating Shifts?

(Initials: G)

Gold et al.

Name the Psychologist who put forth the theory of

Forward rotating shifts?

(Initials: B)

Bambra et al.