BP - Biological rhythms

Question 1

what is a biological rhythm

Answer 1

a change in the body processes of behaviour in response to cyclical changes within the environment

Question 2

what is a circadian rhythm

Answer 2

a 24h cycle e.g. sleep-wake cycle

Question 3

what is an infradian rhythm

Answer 3

a cycle longer than 24h

Question 4

what is an ultradian rhythm

Answer 4

a cycle less than 24h

Question 5

what is SAD (seasonal affective disorder)

Answer 5

• a depressive disorder with a seasonal pattern of onset
• triggered by winter months when daylight hours are limited as prolonged melatonin secretion causes serotonin production
• circannual rhythm

Question 6

AO3 of SAD

Answer 6

• practical application through light phototherapy which uses a lightbox to induce melatonin release
• relieves symptoms in 60% of sufferers
  X however a similar study recorded the placebo effect from 30%

Question 7

what occurs during stages 1 and 2 of sleep

Answer 7

light sleep
easily woken, waves become slower as sleep deepens
theta and alpha waves

Question 8

what occurs during stages 3 and 4 of sleep

Answer 8

deep sleep
slower waves and increased amplitude, difficult to wake
delta waves

Question 9

what happens during stage 5 of sleep

Answer 9

REM
the body is paralysed but brain activity is the same when awake
dreaming occurs

Question 10

what is the research into sleep (D+K 1957)

Answer 10

Dennet and Kleitman
- monitored sleep patterns of 9 adults by EEG, controlled caffeine and alcohol
- found REM activity highly correlated to dreaming - participants woken during REM gave highly vivid description
- small sample size but has been replicated

Question 11

what is the menstrual cycle

Answer 11

an infradian rhythm experienced by women

Question 12

research into the menstrual cycle (S+M)

Answer 12

Stern and McClintock
AIM: investigate the influence of other women’s pheromones on the menstrual cycle
PROCEDURE: 29 women with a history of irregular periods, 9 provided pheromone pads from armpits when on their periods and the other 20 women smelt them
FINDINGS: 68% of the women experienced cycle changes

Question 13

evaluation of research into menstrual cycles

Answer 13

X small sample size, self report so low internal validity
X previous research showed no synchrony
X menstrual synchronisation is not an adaptive strategy