The nature of sleep and lifespan changes Flashcards
Infancy
Babies tend to sleep for about 16hrs a day but not continuously. Their sleep cycles are shorter and include 2 stages; active sleep and quiet sleep. By the age of 6 months, a circadian rhythm has been established, the periods of deep sleep lengthen and there is a reduction in active sleep.
Explain the evolutionary approach towards babies sleep patterns
Babies sleeping during the day allows the parents to get on with chores, enhancing survival. Babies have smaller stomachs so need to be fed regularly.
Why do infants have a higher amount of REM sleep?
Because of the immaturity of the brain, REM sleep is related to the amount of learning that is taking place. REM sleep produces neurotransmitters and consolidates memories. This is supported by premature babies who spend a lot of their time in REM sleep.
Childhood
Children sleep for around 12hrs a day and have more REM sleep still. Boys sleep more than girls but both their overall need for sleep decreases. During childhood, it is not uncommon for children to experience a variety of parasomnias.
Adolescence
Need for sleep increases. Circadian rhythms change so teenagers feel more awake at night and struggle to get up early. One feature of REM sleep is that in males it is often accompanied by orgasm and ejaculation.
How can adolescence sleep be explained in hormone changes?
Hormones are released at night which causes sleep patterns to be disturbed leading to sleep deprivation. Hormonal changes can cause upset to the circadian clock which is described as delayed sleep phase syndrome. Because of this, it has been suggested that schools start their days later to accommodate for this.
How is research in this area culturally biased?
Assumptions are based on American and British samples. Research has found differences in sleeping patterns across 11 countries. One important factor for this was the amount of nights spent outside of the home. (go to sleep lack and lack sleep due to waking early) Sleep deprivation is thus influenced by cultural practices.
Adulthood and old age
‘Normal’ sleep is around 8 hours with 25% spend in REM sleep. There is an increase in disorders such as apnoea and insomnia. Older people have more difficulty going to sleep and wake up more frequently. Older people experience a phase advance with them feeling sleepier earlier and waking up earlier.
Why might too much sleep be a bad thing for adults?
There is an increased mortality risk associated with too much sleep. Research found that those sleeping for 8 hours had a 15% increase in risk of death and the risk was over 30% for those sleeping more than 10hrs. However, this is correlational data as other factors could have influenced their rates.
Older people having reduced sleep may be due to physiological changes
Sleep apnoea or illness can cause an older person to have trouble sleeping. Deep sleep is reduced in older people and so are more easily woken which could be a factor why they have trouble sleeping.
How can poor sleep be explained by old age?
The reduction in SWS leads to a reduction in the production of growth hormones which can explain some of the symptoms associated with old age e.g lack of energy.
IDA-real world application
There have been suggestions that teenagers should start school later to accommodate delayed sleep phase syndrome. The effects of ageing could be reduced by improving the ‘hygiene’ of sleep. E.g. no naps
