L4 Individual Differences Flashcards
(19 cards)
What happens to sleep latency across the lifespan?
There isn’t much difference looking at it generally
It takes infants a bit longer to get to sleep, they can be challenging sometimes
This drops off in adulthood, but then increases again in adulthood
What happens to wake after sleep onset (WASO) across the lifespan?
This is very low in childhood
It increases as you get older, especially after 45, could be due to a whole range of reasons e.g. a weak bladder
What happens to REM sleep across the lifespan?
Children spend quite a lot of time in REM sleep
Drops off a little in adulthood but not too much
What happens to deep sleep across the lifespan?
Spend quite a lot of time in deep sleep as children, this could be linked to development
This reduces in adulthood and reduces even further into the elderly population
Doesn’t necessarily mean they don’t need deep sleep but could be due to brain structure changes
What happens to stage 1 and 2 sleep across the lifespan?
There doesn’t seem to be much difference
What is sleep like in newborns?
Haven’t developed regular circadian cycle, don’t use light as cues so can sleep anytime
Spend 16-18 hours a day sleeping, each episode lasting 2 cycles (50-60 mins each)
Sleep onset is through REM interestingly and spend more time in it compared to adults
Spend a lot of time in stage 3 (deep) sleep
Wake up a lot during the night e.g. for a feed
What is sleep like in the first year?
CRs begin to arise around 2-3 months and begin to use cues, have more of a routine and sleep for longer periods
Sleep onset is now through N-REM but still spend a lot of time in SWS due to development
Have more REM than typical adult still
Cycles are still around 50-60 minutes
TST reduces slightly to 14/15 hours a day, can sleep in the evening with daytime naps
Sleeping through the night for 8 hours is a major milestone achieved by most infants by 6-9 months
What is sleep like in young children (1-5 years)?
TST decreases as they get older, adjusting to physical and social factors e.g. nursery and school.
Sleep cycles start to look more typical (90 minutes)
REM decreases but still happens in first half of the night as well
What is sleep like in teenagers?
Complex relationship due to all the changes in puberty
Have a biologically delayed CR and need around 9-10 hours of sleep
BUT they don’t get that due to a delayed CR and school times preventing that
Sleep patterns vary a lot in teenagers e.g. sometimes not tired enough to sleep at 11 pm so will nap the next day
Also more likely to stay up using phones, games etc which emit blue light - blocking melatonin and delaying sleep even more
More mature children go through puberty earlier and show a later timing of melatonin secretion onset and offset
What have studies of teenagers’ performance shown?
Schools started at 10am instead of 9am at an Oxford school
Performance has been tested at 10am and 2pm and found that amount of correct answers was higher in afternoon testing - due to a delayed CR? (Kelley et al., 2015)
But would require drastic change in society if we were to act on this
What is sleep like in adults?
Reduced REM sleep in older adults, dotted throughout the night not just in the 2nd half
A lot less SWS is observed in the elderly population - links with memory consolidation and implications for neurodegenerative disorders
Shorter cycles in the elderly and more cycles overall - accompanied by lots of awakenings
What are melatonin levels like across age?
Reduced melatonin levels as you get older, biggest increase in 5-10 year olds
Still see increases but not as much - has implications for sleep latency and WASO problems
What are the findings for genes in chronotype preference?
CLOCK genes One of these genes is called Period3 Proposed that: Homozygous PER3 5/5 = Morning type Homozygous PER3 4/4 = Evening Type
Outline the Morningness-Eveningness trend
Seen in levels of body temperature as well
Morning type’s temperature drops around 10/11pm and increases again at 6am
Evening type’s temperature doesn’t drop until later in comparison and picks up around 8/9am
Pattern is similar but there’s a noticeable shift
What did Maire et al. (2014) find?
looked at differences in intentional sleep episodes and melatonin levels in M/E types
Morning types have higher unintentional sleep episodes
These patterns map almost directly onto melatonin levels when melatonin levels are peaking that’s when the UISEs happen
Why do some people need more sleep?
Not a definite answer but is suspected to be something to do with adenosine which builds up during the day as a by-product of ATP
Some people might be more sensitive to adenosine and respond to it differently - potentially sleeping longer as a result?
Research is still investigating
How can the body clock be adjusted medically?
By ingesting melatonin can advance the body clock and delay it in the second half of sleep
What are good about lab experiments in sleep?
You can standardise conditions for sleep e.g. noise levels, temperature, comfort etc.
Can also systematically investigate the separate effects upon sleep and sleep architecture of time of day and time awake
How can you measure chronotype preference?
Using a widely used questionnaire (lark or owl)
