The similarities and differences between primary and secondary literature will be thoroughly compared in this essay through a secondary review article and primary research article both exploring the impacts of chronic sleep deprivation on the human brain. The topic falls under the discipline of neuropsychology as it examines changes in behaviour and cognitive ability as a result of chronic sleep deprivation.
The review article, ‘The sleep-deprived human brain’ synthesises existing knowledge of the consequences of sleep loss on the human brain. Neuropsychology encompasses the studies of changes in cognitive and emotional capacity in relation to brain disorders, and neuroscience involves the study of the nervous system. Both disciplines are identifiable in the article as it revolves around the brain, the vital organ of the central nervous system and effects regions of the brain associated with sleep deprivation, which causes changes in cognitive and emotional processing. It details a variety of impacts to our daily functioning, including attention, memory and decision-making, caused by respective changes in activity of specific regions of the brain. One of which is the prefrontal cortex (PFC), the region of the brain responsible for higher-order cognitive processes including judgement. Referencing a range of first-hand studies, the article explains that a sleep-deprived person experiences changes in the activity of the PFC and are likely to engage in risk-taking behaviour and impulsivity as they become less able to compare the high cost that comes with high reward. (Krause, et al., 2017) The extensive use of neurological terms makes the review mainly targeted towards scientists with a good neuroscientific background and are interested in current research of the consequences of sleep deprivation. This includes neurologists or sleep researchers to aid in clinical settings or inspire their own research into the topic. Although this review article contains simpler sentences in the abstract and a glossary to assist readers, it would still be difficult for an average person to comprehend.
This article is published in Nature Reviews Neuroscience, a peer-review journal specialising in the discipline of neuroscience. It solely publishes reviews in this area, associated with “understanding the structure and function of the central nervous system” and any relevant research to the brain and its impact on movement, cognitive behaviour, language or brain disorders. The journal targets all scientists specialising or interested in neuroscience internationally, serving as a platform that allows efficient communication of knowledge all over the world. (Nature Reviews Neuroscience, 2019)
The primary research paper ‘Impaired decision making following 49 h of sleep deprivation’ covers the experiments conducted on sleep-deprived participants undertaking the Iowa Gambling Task (IGT), a task that simulates real-world decision making. This research is significant to neuropsychology by providing evidence to support theories of the different regions of the brain responsible for certain behavioural changes and the factors that may affect it. This experiment focuses on how sleep deprivation affects the functioning of the PFC, which influences decision-making. The research aimed to investigate the effect of sleep loss on the quality of judgement and risk-taking, hypothesising that two nights of sleep loss would result in impaired decision-making and increased risk-taking behaviour, and would also align with the results of brain-injured patients in the prefrontal lobes. (Killgore, et al.,2006)
The results showed that after 49.5 hours of sleep deprivation, participants would gradually engage in riskier actions as they prioritised short-term high gains, with extremely high losses, eventually leading to a net debt. Whereas when well-rested, would gradually prioritise safer, short term low gains, leading to a net gain. This demonstrated that sleep loss affected the ability of participants to weigh the benefit of short-term reward against long term punishment, proving that sleep deprivation impairs decision making and increases risk-taking behaviour. Further, the trend of sleep-deprived participants was similar to that of the brain-injured participants, suggesting that sleep deprivation could heavily impact the functioning of the PFC. Therefore, the experiment was able to determine a correlation between sleep deprivation and impaired judgement as well as the connection between sleep deprivation and the PFC, proving the adverse implications of chronic sleep deprivation on our actions and behaviour. (Killgore, et al.,2006)
The primary article is one of many research papers referenced in the review to summarise the main impacts of sleep loss on the human brain. The IGT was one experiment used as evidence supporting the theory of limited perception of reward or punishment value following sleep deprivation. The results surrounding participants’ impaired judgement were explicitly mentioned, helping to validate the information presented in the review. However, the findings of the correlation to regions of the PFC were not mentioned, with the review referencing other experiments with greater detail into the more specific regions responsible for changes in decision-making. Thus, the primary article had a small but important contribution towards ensuring the academic quality and reliability of the review’s theory.
Both articles increased my awareness of the consequences of sleep deprivation and the effect it would have on my daily life, primarily influencing my concentration, judgement and ability to think. As I tend to sleep late every day, it was definitely an eye opener towards the damage that could occur from my unhealthy lifestyle choices. Although both articles include neurological jargon that made it difficult to understand, the review article was structured clearly with subheadings naming each consequence on behaviour and the research article had clearly stated the key points of their experiment in the introduction. This made it easier to identify the main points of the articles and gain a better general understanding of the topic overall.
Whilst secondary literature summarises findings from a variety of primary research to provide a general overview of the topic, primary literature details a scientist’s experiments focussing on a specific detail of the topic. This was explored in the essay as the review article provided a summary of the implications of sleep deprivation on cognitive and emotional processing, whereas the research article centred around only the effect of sleep loss on decision-making. Both types of literature work hand-in-hand to prompt further research into the area or create awareness into the neurological processes and implications of sleep deprivation. Thus, scientific literature is an important method of communication between scientists to share and improve knowledge and understanding of science and the world.