PYC4813 - Cognitive NeuroScience Assignment 2.

PYC4813 - Cognitive NeuroScience Assignment 2. The biology of sleep. Sleep is an essential and fascinating physiological process that forms part of our daily lives, as human beings it is commonly known that the average amount of sleep that we need is approximately 8 hours a day (Kalat, J.W., 2016). By means of our biological clock, which is our brains innate timing device, our bodies generate a biological rhythm that influences and controls our sleep-wake patterns and behaviours (Kalat, J.W., 2016). This biological rhythm is referred to as the circadian rhythm (Sue, D., et al, 2016). Our circadian rhythm produces a sleep-wake cycle of close to 24 hours and due to many different circumstances and conditions this 24-hour period is prone to readjustments every now and then (Kalat, J.W., 2016). Research has found that as a person sleeps they go through 5 stages over the course of 90 minutes (Kalat, J.W., 2016). These stages of sleep are important as each stage is characterised by different wave lengths and internal behaviours. When a person is asleep, they start at stage 1 and the gradually progresses to stages 2, 3 and 4, after 60 minutes the cycle reverses from stage 4 to stages 3, 2 and then REM (Kalat, J.W., 2016). Stage 1 is characterised by irregular, low voltage, rapid waves, and during this stage the individuals brain activity starts to decrease, their heart rate slows down, and breathing become regular and deep (Deventer, V.V., & Mojapelo-Batka, M. 2013). Stage 2 is characterised by sleep spindles and k-complex waves thus, this stage sleep is deeper and wave frequencies fluctuate (Deventer, V.V., & Mojapelo-Batka, M. 2013). Stages 3 and 4 are both characterised by slow, large-amplitude waves, as the 2 stages Page | 2 PYC4813 Assignment 2: work together. A person on stage 3 and 4 of their sleep would also show a decrease in brain activity, heart rate and breathing (Deventer, V.V., & Mojapelo-Batka, M. 2013). And the final stage of sleep is known as REM (Rapid eye movement) sleep, which is characterised by low amplitude and high frequency waves. REM sleep is a combination of light and deep sleep instead of either or, and a person at this stage of sleep shows signs of facial and eye movements as dreaming takes place at this stage of sleep (Kalat, J.W., 2016). The brain consists of various mechanisms that are responsible in forming our wakefulness, arousal and sleep patterns. Sleep relies on the decrease of sensory stimulation to the cerebral cortex, which is made possible by neurons found in the thalamus (Kalat, J.W., 2016). While arousal relies on the structure called pontomesencephalon which maintains wakefulness and alertness, the structure releases neurotransmitters such as acetylcholine and glutamate which increase the level of cortical arousal (Kalat, J.W., 2016). In relation to this research study, focus is placed on the duration and quality of sleep with reference to the relationship between the 2 variables. The duration of sleep is the number of hours a person is asleep for, which is determined by the time a person goes to bed to the time they get up the next morning and the quality of sleep is a subjective experience of how the person rates their sleep (Peuhkuri, K. 2012). Previous research by Mesas, A. E., et al (2011), have shown that short duration of sleep which is 5 hours and less, have been associated with poor qualities of sleep. Another focal point to this study includes the effect of stress has on the duration and quality of sleep, as stress points out to be an indicator of people falling in to depression and developing sleep disorders (Becker, B.N., et al, 2015). When a person is exposed to demanding social environment, work environment and home environment, this can result in an extreme level of stress causing them to not get enough sleep and in turn resulting in a poor quality of sleep (Becker, B.N., et al, 2015). Lastly, another interesting point of this study is to investigate if certain foods influence dreaming as proven research circulating those variables are insufficient. However, it has been documented that certain foods contain substances that influences our emotions, moods, memory and other aspects which causes us to feel tired or more alert, and in turn could probably influence the way we dream or remember our dreams (Carr, M., 2018). Page | 3 PYC4813 Assignment 2: Aim of the study. Research questions The following research questions highlighting this study are; a.) Is there a relationship between the quality and duration of sleep? b.) Does the level of stress have a negative effect on the duration and quality of sleep? and c.) Does the ingestion of dairy products and spicy food have an influence on dreaming? Research hypothesis The results of the study will be correlated with the following research hypothesis; a.) There is a positive relationship between the quality and duration of sleep. b) The amount of stress experienced demonstrates a negative effect on the quality and duration of sleep. And c) The ingestion of dairy products and spicy foods could possibly influence dreaming due the different substances they give off in the body. Methods Study design and sample To conduct this study a sample of 6 participants were recruited to test the above hypothesis which aims to investigate if there is a positive relationship between the quality and duration of sleep, if stress negatively effects the duration and quality of sleep and if the ingestion of dairy products and spicy foods influences dreaming. Participants that were selected had volunteered to take part in the study by means of an informed consent form that they had to read and sign, which also included the nature of the proposed study. Sample demographics varied along differences in age, gender, race, ethic background and so forth, although demographics where not relevant for the study. Procedure and instrument used for the study.