Nature of Sleep

Question 1

How are circadian rhythms controlled?

Answer 1

By the SCN and fine-tuned by exogenous zeitgebers

Question 2

What happens during sleep during the night?

Answer 2

We do through 5 cycles, each one lasting about 90 minutes with REM increasing during the night

Question 3

How are the different stages and cycles of sleep distinguished?

Answer 3

Through EEG (brain waves) as frequency and amplitude differs

Question 4

Name 2 main differences in sleep among species

Answer 4

1) Time spent sleeping varies

2) REM absent in some like reptiles

Question 5

Name 2 things suggested about sleep

Answer 5

1) It is necessary for survival otherwise why would all animals do it?
2) Patterns of sleep are adaptive to each particular species otherwise why are the patterns so different?

Question 6

Explain a positive evaluative point about the nature of sleep

Answer 6

Objective evidence from EEG readings providing objective measures of sleep

Question 7

Explain 3 negative evaluative points about the nature of sleep

Answer 7

1) Sleep labs are reductionist as do not reflect many factors that can influence sleep in real life - lacks mundane realism, lack of generalisability and ecological validity
2) Individual differences - most 5 cycles and about 8 hours but some sleep less and much more so patterns vary between individuals
3) Self-report techniques vulnerable to bias due to researcher effects and ppt reactivity so may lack validity