End bits of biopsych

Campbell and Murphy

15 ppts in lab, woken up at various times and had light shone on back of their knees

Circadian rhythms disrupted by up to 3 hours

Suggests light is powerpuf exogenous zeigeber and don’t necessarily need to rely soley on visual input

Shih-YU LEE

Mothers with premature babies can have more sleep distrubances due to strees and dim lighting. - Desynchronises circadian rhythms.

Mothers given bright light therapy for 3 weeks and sleep monitored.

Mothers reported better sleep in length and quality.

Bright light therapy

Done for 30 mins in 1st waking hour

Blue-green light slightly softer thab full daylight.

PPts wears visor screen

Helps reset melatonin function

Steel et al

Monitored individuals living in artic with costant daylight for 6 weeks.

Ppts kept sleep logs

Found 5/6 developed free-running cycles, longer than average 24 hr cycle

Sleep patern individual

Positive for exogenous zeitagebers

P - Real life app to jet lag

E - Can be serious condition causing mood, sleep and appetite disturbance

E - Burgess found exposure to bright light on long flight decrease time needed to adjust

L - Can enterain circadian rhythms to fit into new zones

Negative for EZ

P - Influences overstated

E - Miles et al. Circadian rhythm was 24.4 hrs dispute social cues not being adjusted

E - Some people in arctic show normal sleep paterns

L- Suggest Ezs may have little effect on bio clock

Infradian rhythms

Rhythm in cycle more than 24 hours

Menstrual cycle 28 days

Levels of oestrogen cause ovary to develop egg and release it

Progesterone causes womb lining to thicken, ready for pregnancy

If pregnancy doesn’t occur than egg absorb and lining leaves body

McClintock and Stern

10 yr longitudinal study

29 women with history of irregular periods

Samples of pheromones gathered from donors under their armpit

Rubbed on upper lip of ppt (daily)

68% women’s cycle synchronised to donor’s

Reinberg

Woman spent 3 months in cave with dim light

Menstrual cycle shortened to 25.7 days and took yr to retun to normal outside of cave

Seasonal affective disorder

Diagnosed as mental disorder in DSM-5

Form of depression, with persistnet low mood and lack of activity

Utlradian rhythms

Rhythm in cycle less than 24 hours

Typically lasts around 90 minutes

Most will go through 4-5 cycles a night

Different stages with different levels of brainwave activity

Measured using EEG’s

Sleep cycle

5 stages of sleep

Stage 1 - light sleep, easily woken. Alpha brain waves

Stage 2 - Theta Brain waves ( even slower)

Stage 3 - Delta brain waves (slower and deeper)

Stage 4 - Deepest stage of sleep

Stage 5 - REM. Dreams occur

Dement & Kleitman

9 ppts in sleep lab

Recorded brain wave activity using EEG

REM activity correlated with experience of dreaming

PPts work during REM and were able to recall dreams in detail

Negative of Ultradian rhythms

P - Methodological issues WIth D&K

E - Sleeping in different bed in different environment changes sleeps

E - Means that they might have a better sleep in one environement then another

L - Lack reliability

Positive for UR

P - Practical application

E - Light therapy developed because of sleep research

E - Resets levels of melatoning, helping sleep

L - Useful for treating SAD, found to be successful in up to 60% of cases

Positive for IR

P - Evidence for SAD

E - Terman found rate of SAD more common in New Hampshire than Florida

E - Significant difference but correlation data doesn’t show cause + effect

L - Could be lifestyle differences

Negative for IR

P - Methological issues

E - Relaint on self-report data

E - Case study evidence and small sample. not generalisable

L - Potential confounding variable