Czeisler Et Al

Question 1

What was the aim

Answer 1

To test wether exposure to bright light would help nightshift workers adapt to daytime sleeping

Question 2

When was the experiment preformed

Answer 2

1990

Question 3

What was the method

Answer 3

Eight men cans to the laboratory to work “nightshifts” six consecutive evenings all were 22-29 years old and took place in summer months. The men had no prior experience to nightshifts and had not travelled recently they were also asked to abstain from alcohol and caffeine. They preformed cognitive tests and self report on mood and alertness. While in nightshifts they were exposed to very bright light and complete darkness during the day. (The control group had normal artificial light at night and normal light in the day). The core body temperature was recorded continuously.

Question 4

Findings

Answer 4

The experimental group had their circadian rhythms shifted by around 9 hours with their melatonin secretion being highest at 12 noon and slept two hours longer than the control group and their alertness was higher after exposure to the bright light than before.

Question 5

What was their conclusion

Answer 5

That with a proper routine of light and dark a person could experience a physiological adaptation to night work

Question 6

Evaluation strengths

Answer 6

Gave insight to the physiological effect of night working
Because it took place in a laboratory the factors were easily controlled which allows for a cause and effect relationship to be established

Question 7

Evaluation weaknesses

Answer 7

The sample size was small and age range was low therefore not applicable to wider population

Method lacks ecological variety as they had to complete lots of tests throughout the night

Several variables such as (time breakfast was ate or sleep time) was not controlled