Sleep Deprivation and Circadian Rhythms

The science behind sleep deprivation and circadian rhythms has advanced over time, meaning that the neurobiological pathways that drive human alertness and performance have become better understood. In this portfolio, it will discuss the state of the science regarding sleep and performance relating to doctors and how the use of light therapy can help overcome sleep deprivation for doctors.

Sleep deprivation is an acute or chronic lack of sufficient sleep resulting from disruption to the natural sleep wake cycle. Doctors and nurses regularly work long shift schedules where they are often required to work beyond their hours. For example, the BMA UK-wide quarterly survey results published showed that 74% of GP’s, 65% of consultants and 70% of trainees often worked outside of their regular hours in the last month (British Medical Association 2017).

Numerous theories have been developed and planned by psychologists to describe the function of sleep. Oswald et al (1966) believed the role of sleep is to restore the body during stages of inactivity so that sufficient biological functioning is guaranteed. Specifically, Oswald suggests that NREM sleep (Non-REM) restores biological processes that have worsened throughout the day and REM sleep (Rapid Eye Movement) replenishes and restarts brain processes by the process of protein synthesis. Animal studies of sleep deprivation backs up the restoration theory as they show that biological functioning worsens if an animal is disadvantaged of sleep. However, results of human studies are as not strong and do not seem to support the idea that biological functioning is disturbed if a human is deprived of sleep.

Research supports the idea that sleep has the role to restore and replenish biological functions and processes. However, research of sleep deprivation in humans do not so far specify that it causes serious biological malfunctions and how cell repair has been shown to carry on for 24 hours a day, meaning it is not confined to sleep periods. Tripp et al (1956) further supported this theory by attempting to stay awake for 8 days. Tripp slept for longer than normal which resulted in hallucination where the brain worked too hard as it did not have time to replenish itself. Many ethical and methodological issues were involved in this study.  Majority of the research was conducted on males resulting in the sample being androcentric and not generalised to females. The experiment was undertaken in a controlled environment using drugs and help of other individuals to help keep him awake. Therefore, the findings are not ecologically valid as it does not reflect a real-life situation.

However, this is beneficial as the controlled settings enabled a clear origin and effective relationship to be recognised. Moreover, it was a case study in which it would prompt qualitative data, but it is also ideographic as it is only based on an individual, preventing it from being generalised to the wider population. The validity of these findings can be challenged as there was a vast amount of issues that were arisen. By using the self-report method, it enables the research findings to social desirability and open to bias, thus reducing objectivity. This is shown in Webb and Bonnet’s research (1978). Participants reported feeling satisfactory with no opposing effect after partial sleep deprivation which contrasts to how most individuals would feel if they were put into this situation. This implies that the participant’s may have wanted to come across more capable than they were just to amaze the researcher.

The hibernation theory (Webb 1974) suggests sleep evolves by enabling organisms to have a better chance of survival in a antagonistic environment. Precisely, Webb believes sleep has evolved due to animals conserving energy and those who conserve energy are more prone to survival compared to animals that do not. Hence, they are more likely to pass energy on to the next generation. Examples to support this theory is the rate of heat loss, diet etc. In terms of rate of heat loss, the smaller the animal is, the faster it will lose heat therefore they will sleep more compared to larger animals due to heat loss being an important factor of the waste of energy.

This theory consists of many evolutionary issues that could possibly affect sleeping patterns. For example, prey animals are at a bigger risk of attack compared to predators. There is no variation in sleep patterns that cannot be described by using evolutionary concepts. However, at the same time there is no way of determining which factors are important resulting in the theory being unfeasible therefore it cannot be a scientific theory. Furthermore, it does not discuss why sleep is universal as it can be possible to find evidence of animals that do not sleep. Most of the research is grounded from animal studies therefore meaning that the findings cannot be practical to humans due to variations in sleeping patterns and environmental patterns. Due to this theory not being a representation of human sleep it shows that evolutionary theories are quite difficult to validate as they lack experimental backing and scientific validity due to it being planned in retrospect.