1. 1. BIORHYTHMS
   
2. 2. Are you a Lark or an Owl???
   Owls often skip breakfast, and they're always rushing to get to work in the morning.If you're an owl, you'd struggle to be a milkman.Most college students and 20-somethings are owls. They need multiple alarm clocks to get up in the morning!
   Larksrarely nap, and prefer to exercise in the morning.They are most productive late morning, and go to sleep on average 2 hours before owls, falling asleep faster.If youre a lark, you wouldnt enjoy a job as a night-time bartender.
   
3. 3. Our body and behaviour goes through VARIOUS DIFFERENT CYCLES that last for varying DURATIONS.
   These may be SYNCRONISED with ENVIRONMENTAL CONDITIONS.
   Eg. We our SLEEP/WAKE CYCLE runs with the DAY/NIGHT CYCLE.
   
4. 4. CIRCADIAN RHYTHM
   Lasts about 24 HOURS.
   SLEEP/WAKE CYCLE.
   Synchronised with DAY/NIGHT.
   
5. 5. BODY TEMPERATURE
   Lowest in the evening when it drops to approx. 36.7 degrees and highest at mid afternoon when it rises to 37.1 degrees.
   Mid afternoon is associated with;
   HIGHER RESPIRATION
   HIGHER BLOOD PRESSURE
   
6. 6. ULTRADIAN RHYTHM
   A cycle that occurs more than once in 24 hours.
   EXAMPLE
   The Sleep Cycle
   e.g stage 1,2,3,4,3,2, REM etc
   
7. 7. The use of an electroencephalogram (EEG) can show the electrical activity of the brain.
   There are different patterns of activity at different times during sleep (Rechtschaffen & Kales, 1968).
   
8. 8. Each sleep cycle, from NREM to REM sleep, lasts approx. 90 MINUTES.
   NREM REM NREMREMNREM REM
   90 mins90 mins90 mins
   
9. 9. INFRADIAN RHYTHMS
   Last over 24 HOURS.
   E.g. MENSTRUAL CYCLE
   These cycles are internally managed but can also be effected by external factors.
   It can synchronise with the cycles of other women, if living in close proximity!
   
10. 10. Infradian rhythmscan occur as a result of seasonal changes.
    For example, migration and hibernation are called circannual rhythms.
    
11. 11. What type of bodily rhythmsare these?
    
    The sleep-wake cycle over one-day
    Eating several times a day
    Body temperature rises in the morning and drops later at night
    Menstrual cycle (approx every 28 days)
    
    Seasonal Affective disorder
    Migration in birds
    Sleep stages that occur every 90 minutes
    Smoking a cigarette the nicotine effect
    
12. 12. What determines the length of these rhythms??
    Body Size?
    Age?
    Lifestyle?
    (NATURE VS NURTURE) (Discuss)
    
    There are clearly individual differences in Biological Rhythms!
    In built stopwatch?
    Owls or larks?
    
13. 13. Built in stopwatch Experiment
    Sometimes it seems as if time flies bysometimes it drags on forever.
    How good are you estimating time?
    Do you have a built in stopwatch?
    Estimate the length of a period of time, e.g. one minute.Tell Xto count to 60 by ones at a rate of one per second.When say GO start your timer.When Xgets to 60, stop the timer.How close was your X?
    
14. 14. WHAT CAUSES THESES CYCLES/ RHYTHMS?
    INTERNAL FACTORS?EXTERNAL FACTORS?
    For each piece of research you discuss, not only should you use general AO2, but also say whether they are evidence for INTERNAL or EXTERNAL FACTORS!
    VITAL!
    
15. 15. For example, what factors control our sleep/wake cycle?
    
16. 16. SLEEP WAKE CIRCADIAN RHYTHM - INTERNAL BODY CLOCK
    Or ENDOGENOUS PACEMAKER.
    The suprachiasmatic nucleus (SCN) in the hypothalamus is a bundle of nerves with an inbuilt circadian rhythm. This is a particularly important endogenous pacemaker.
    
17. 17. Evidence for this comes from studies in which the SCN has been cut in hamsters to result in disrupted circadian rhythms (Menaker et al., 1978).
    
18. 18. EXTERNAL FACTORS
    Or EXOGENOUS ZEITGEBER.
    LIGHT!
    Flashes of light are enough to 'reset' the internal clocks of animals living in the dark (Aschoff, 1979).
    
19. 19. THE SCN HAS CONNECTIONS TO THE PINEAL GLAND......
    
20. 20. One blind man needed to take stimulant and tranquilizing drugs to maintain a 24 hour cycle!
    WHY?
    
21. 21. Here are some important points to note:
    Each cycle lasts for about 90 minutes.
    The amount of Stage 3 & 4 sleep decreases each cycle.
    The amount of REM sleep increases each cycle.
    
22. 22. EATING PATTERNS
    Approximately every 5 HOURS.
    Breakfast (8am), Lunch (1pm), Dinner (6pm)
    These RHYTHMS can be destroyed by LESIONING part of the HYPOTHALAMUS.
    
23. 23. REMEMBER.
    ENDOGENOUS PACEMAKER internal timekeeper
    EXOGENOUS ZEITGEBER external factor effective biorhythms
    ZEITGEBER time-giver.
    
24. 24. EXAMPLE OF AN INFRADIAN RHYTHMS
    What are the ENDOGENOUS PACEMAKERS involved in the MENSTRUAL CYCLE?
    
25. 25. HORMONES
    Menstrual cycle roughly 28 days
    OESTROGEN and PROGESTERONE released by the ENDOCRINE glands.
    
26. 26. These hormones cause the release of an EGG and engorge the LINING of the WOMB.
    If the egg is not fertilised, the lining of the womb is shed.
    
27. 27. NEXT JOB..
    Answer questions on pages 34 and 35 using the FLANAGAN article.
    
28. 28. FOR EVERY PIECE OF RESEARCH you must do TWO THINGS;
    Decide whether it is evidence for EXOGENOUS ZEITGEBER or ENDOGENOUS PACEMAKER.
    Try and EVALUATE the study itself.
    
29. 29. SIFFRE (1975)
    Lived in a cave with no external time cues.
    NO NATURAL LIGHT, NO CLOCKS (i.e. no means of telling the time)
    
30. 30. He kept a detailed PHYSIOLOGICAL record of his bodily processes using scientific equipment (AO2) and found that his sleep wake cycle was still CIRCADIAN.
    It had extended to 25 hours but once extended remained on a 25 hour cycle.
    WHAT DOES THIS SUGGEST?
    
31. 31. SIFFRE AO2?
    
32. 32. FOLKARD et al (1985)
    Isolated his participants from EXTERNAL TIME cues.
    Exposure to light was also CONTROLLED.
    They gradually reduced the ppts daily cycle by REDUCING both LIGHT and DARK.
    
33. 33. AO2 FOLKARD (page 34)
    FOLKARD et al (1985) Used 12 PARTICIPANTS Small sample size.
    LIGHT CUES were controlled but what about OTHER EXOGENOUS ZEITGEBERS? E.g. Social cues that can effect our CIRCADIAN RHYTHMS
    
34. 34. It was found this did have an effect.
    CYCLES reduced to 23 HOURS.
    HOWEVER, further reductions in light and dark led to return to a NORMAL CIRCADIAN CYCLE.
    What does this suggest?
    
35. 35. Siffre(1975) ENDOGENOUS PACEMAKER or EXOGENOUS ZEITGEBER?
    Folkard et al (1985) ENDOGENOUS PACEMAKER or EXOGENOUS ZEITGEBER?
    
36. 36. BIOLOGICAL CLOCK
    Bundle of nerves in the SCN (located in the HYPOTHALAMUS)
    Connected to the EYE and the PINEAL GLAND.
    SCN receives information from the EYE and passes this on to the PINEAL GLAND.
    
37. 37. The PINEAL GLAND secrete the hormone MELATONIN which leads to a decrease in LEVELS of AROUSAL. i.e. we get tired!
    
38. 38. The effect of MELATONIN and the identification of the SCN in the HYPOTHALAMUS has been the result of scientific methodology. (AO2)
    
39. 39. IF THERE IS A LACK OF DAYLIGHT, THIS INFORMATION IS SENT TO THE PINEAL GLAND.
    THIS LEADS TO RELEASE OF THE HORMONE, MELATONIN.
    THIS DECREASES AROUSAL and MAKES US SLEEPY.
    
40. 40. Heard of Seasonal affective disorder?
    What is it?
    How might the amount of Melatonin released cause SAD?
    
41. 41. In humans, the increased levels of melatonin in autumn appears to lead to a form of DEPRESSION.
    This is known as SAD (seasonal affective disorder).
    This can be treated by exposure to a bright light for several hours per day.
    
42. 42. DAMAGE to the SCN?
    If connections to from the EYE to the SCN are damaged, or the SCN itself is damaged CIRCADIAN RHYTHMS disappear completely.
    WHAT DOES THIS SUGGEST?
    
43. 43. Evaluation of research studies into Circadian rhythms
    - What PRACTICAL APPLICATIONS? could we gain from studies such as these(how useful is this stuff really???)
    - Deciding the BEST TIME TO STUDY.
    - Addressing SHIFT WORK and JET LAG.
    
44. 44. GENERAL AO2
    CIRCADIAN RHYTHM (SLEEP WAKE CYCLE)
    Reaction to manipulation of SLEEP/WAKE CYCLE may depend on whether youre an OWL or a LARK.
    
45. 45. RECENT RESEARCH
    Suggests we have two distinct biological clocks.
    That which governs the SLEEP WAKE CYCLE.
    That which governs BODY TEMPERATURE.
    We know this from experiments of light deprivation.
    
46. 46. ZEITGEBER
    TIME GIVER!
    
47. 47. ENDOGENOUS PACEMAKERS can be influenced by EXOGENOUS ZETIGEBERS.
    What is an EXAMPLE?
    How might this be ADAPTIVE or USEFUL?
    
48. 48. OTHER EXAMPLES of EXOGENOUS ZEITGEBERS
    TIDES the menstrual cycle is linked to the LUNAR CYCLE.
    TEMPERATURE
    AVAILABILITY OF FOOD
    PHEROMONES.
    
49. 49. Duffy et al (2000) found EARLY RISERS prefer 6am-10pm cycles and LATE STARTERS prefer 10am-1am cycles.
    
50. 50. What are PHEROMONES?
    Chemicals that trigger a response in the same SPECIES.
    http://www.troohealthcare.com/pheromone-fragrances-10/troo-attraction-pheromone-perfume-11.html
    
51. 51. RUSSELL et al (1980)
    As previously discussed the MENSTRUAL CYCLE is primarily governed by.WHAT?
    RUSSELL et al (1980) collected daily samples of WOMENS SWEAT.
    This was applied to the upper lips of FEMALE PARTICIPANTS.
    
52. 52. They found the MENSTRUAL CYCLES of DONORS and PPTs BEGAN TO SYNCHRONISE.
    Why was this?
    
53. 53. AO2
    Pheremones are not CONCIOUSLY detectable which makes detection difficult.
    Could it have been something else contained in the SWEAT?
    
54. 54. AO2
    SYNCHRONISATION Why might this be of use?
    Russell found 4 of the 5 women in the experimental group were synchronised. AO2?