Correlation between age and sleep

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Correlation between age and sleep

Psychology A level coursework

by Bozena Ewertowska

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The area of study was duration of sleep. The aim of this activity was to measure the correlation between sleep and age. Past research has shown a negative correlation, which means as we grow older we have less sleep.  

The research method was survey, and a sleep diary was used to collect the data. Sleep diary were recorded over seven consecutive days.

There were 26 participants, males and females, aged 17 – 53. The participants were chosen using opportunity sampling.

Weak correlation has been found on scattegraph but the correlation was not significant (p=0.05, critical value = 0.331, observed value = - 0.250). Therefore the null hypothesis was retain. There is no correlation between age and sleep.

Further analysis of sleep duration in age group showed that the higher needs for sleep are required by young people, age group 17 – 20, 20 – 30. Duration of sleep’ people over 30 are the lowest, just around 6 hours. This could be related with family and work responsibility associated with this age. People in age 40 – 53 sleep longer as they are more aware of the influence of sleep hygiene for our health.

This suggests that is not the need for sleep but the ability to sleep is reduced.  Must be that others than only ageing changes factors are affecting the human been ability to sleep.  Further research should be conducted so we could find how age, socio-economic circumstances and health status are associated with human  sleep quality.

1. Introduction

The need for sufficient, sound sleep has worldwide importance. As industries around the world are increasingly implementing shift work (round-the-clock) schedules, millions of people are changing their sleeping habits. In addition, due to the sleep disorders mentioned below, as well as, to fast-paced lives, many people go without adequate sleep. These habits can have serious consequences. For instance, automobile accidents increase dramatically among people with sleep disorders. Sleep disorders also cause problems in the workplace that effect society as a whole.

It is commonly know and proofed that not getting enough sleep can affect different people in different ways and depends very much on our daily routine. It can make us irritable, worried or nervous, unable to concentrate or cope with even the simplest of tasks. We may find ourselves feeling drowsy during the day, becoming forgetful or more accident prone than usual. Often people who are suffering from insomnia may feel short tempered and more likely to become impatient with others.

That is why study on sleep quality is such important.

1.1. Background research

Through out previous research it has been found that there is a significant negative correlation between sleep and age. But to understand the correlation firstly we need to understand sleep.

Study conducted by Dement and Kleitman (1957) helps us to understand more about sleep. Falling asleep is not a passive activity. Our healthy (and normal) sleep consists of two basic stages: REM (rapid eye movement) and non-REM. The non-REM stage is further broken down into four sub-stages, with the first stage reflecting the beginning of sleep. During stages three and four, delta sleep occurs. Delta sleep is our deepest and most restorative sleep stage. After the fourth stage of non-REM, we enter REM, where dreams occur.

The progression through the stages is marked by decreasing frequency and increasing amplitude of the EEG (electroencephalograph). REM sleep is characterized by fast, desynchronized EEG activity resembling the awake stage. These cycles continue throughout the night, the SWS (slow wave sleep) period getting shorter and the REM period getting slightly longer as the night progresses. REM is also identifiable by the loss of muscle tone, our bodies are effectively paralyzed.

Later research by Habsom (1987) showed the relationship between REM and non-REM over a lifetime. Each sleep is about 60 minutes in early infancy and increases to 90 minutes during adolescence.  

A. study conducted by researchers at the University of Chicago, in particular Dr Eve Van Cauter, found a strong link between sleep and aging. She found that sleep deteriorates at two points in a person's life - between the ages of 16 and 25 and again between the ages of 35 and 50. While the total time of sleep may remain the same she reports that the quality of sleep deteriorates, with less and less time being spent in a state of slow wave or deep sleep. The study shows that total deep sleep decreases from nearly 20% of a normal nights sleep for those under 25 to less than 5% for those over 35 years of age. There seems to be a relationship between the amount of human growth hormone secreted in the body and the quantity of deep sleep.

Research conducted by The National Foundation of Sleep in US demonstrates that our sleep needs remain constant throughout adulthood. According to opinion of the researchers it is a common misconception that sleep needs decline with age. Changes in the patterns of our sleep – what specialist call "sleep architecture" – occur as we age and this may contribute to sleep problems.  As people age they tend to have a harder time falling asleep and more trouble staying asleep than when they were younger.

In addition to changes in sleep architecture that occur as we age, other factors affecting sleep are the circadian rhythms that coordinate the timing of our bodily functions, including sleep. For example, older people tend to become sleepier in the early evening and wake earlier in the morning compared to younger adults. This pattern is called advanced sleep phase syndrome. The sleep rhythm is shifted forward so that 7 or 8 hours of sleep are still obtained but the individuals will wake up extremely early because they have gone to sleep quite early. The reason for these changes in sleep and circadian rhythms as we age is not clearly understood. Many researchers believe it may have to do with light exposure.

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Compared to normal sleep cycles the elderly have more fragmented poor quality sleep. Slow wave sleep is reduced indicating poor rejuvenation of tissues as growth hormone secretion is reduced. There is an increased in stage 1 and 2 sleep with more fragmented REM sleep indicating more dreaming. Age related changes in sleep are due to weaker circadian regulation of sleep and wakefulness. Manipulation of the circadian timing system, rather than the sleep homeostat, offers a potential strategy to alleviate age related decrements in sleep and daytime alertness levels. [Kales and Kales. 1974). In summary the aged can experience the following: ...

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