Biological Rhythms

Question 1

Circadian rhythm definition

Answer 1

24hour ‘body clock’
Which gets reset by levels of light

E.g sleep wake cycle, dictates when humans and animals should be asleep and awake. Light provides the primary input to this system acting as an external cue for sleeping or weeking

Question 2

Circadian rhythm research

Answer 2

Micheal siffre

• spent most of his life in caves to see what would happen to his biological rhythms.
• isolated from cues no indication of time
• 61 days in his body clock slowed and he thought it was the 20th aug but it was 21st sept

Question 3

Evaluation - positive for shift work

Answer 3

Research has shown that extreme alternations in bio rhythms can have life long stress implications.

• reduced concentration after 6am
• can have positive economic implications as managers can better rota employees with this in mind

Question 4

Evaluation negative individual differences

Answer 4

CHRONO TYPES
Lark and owl.
Some people are morning people
Some people are evening people

• so there are innate differences in circadian rhythms
• not all research takes this into account

Question 5

Ultradian rhythms definition

Answer 5

Last fewer than 24 hours and can be found in pattern of human sleep.
Sleep stages

Question 6

Stages of sleep

Answer 6

• 1 and 2 are light sleep (alpha waves to theta waves)
• 3 and 4 are deep sleep (delta waves)
• 5 REM (dream) sleep body is paralysed to stop acting out their dream

Question 7

Randy Gardner research

Answer 7

Remained awake for 264 hours

• blurred vision and disorganised speech
• after he slept for 15 hours and recovered only 25% of lost sleep
• recovered 70% of Stage 4 and 50% of REM
• highlights flexibility in diff stages of sleep cycle

Question 8

Evaluation negative individual differences

Answer 8

Tucker et al 2007
Found difference in participants of duration of each stage (stage 3 and 4)
-due to innate individual differences in ultradian rhythms

Question 9

Infradian definition

Answer 9

Longer than 24 hours can be weekly, monthly or annually

Eg female menstrual cycle

Question 10

Research to support menstrual cycle as infradian

Answer 10

Women have an evolutionary advantage if they synchronise menstrual cycle so child care can be shared across multiple women who have babies @ same time