The Essay Explores The Link Between Sleep And Cognitive Functioning.

Understanding the Effects of Poor Quality Sleep

Gosselin et al., (2019) stated in his paper that the poor quality sleep affects the immune system of the body. It also affects the cognitive abilities of the body and weight management. Sleep can affect the psychological wellbeing of every person. Disturbed sleep affects the brain health of the elderly mainly creating obstructive sleep apnea (OSA) which causes sleep apnea and has neurocognitive consequences in older adults. OSA effects in multiple cognitive domains like attention, vigilance and working and episodic memory. It also affects executive functioning. The paper claims that the link between cognitive decline and OSA due to sleep disturbance has in the recent past drawn attention and is being extensively researched on. Thus, the link between sleep disturbance induced OSA and disturbance in cognitive functioning is still weak.

Supporting the conclusions drawn by Gosselin et al., (2019), the present paper conducted by Muehlroth, Rasch & Werkle-Bergner, (2020) supported that sleep helps in stabilization the newly acquired information and this process is called memory consolidation in elderly. Unlike the other papers, Muehlroth, Rasch & Werkle-Bergner, (2020) in their paper stressed that sleep physiology has the power to affect memory consolidation resulting in lower episodic memory performance in healthy older individuals. Thus, the paper concluded that the effect of age on sleep and memory is not comprehensive yet. Supporting conclusions drawn by Klinzing, Niethard & Born, (2019), Muehlroth, Rasch & Werkle-Bergner, (2020) also argued that sleep oscillations which occurs during deep NREM sleep, leads to reactivation, integration, and redistribution of memory traces. 

Unlike Gosselin et al., (2019) who have discussed the effect of sleep on the cognitive disturbance of elderly people, De Bruin et al., (2017) have discussed the effect of sleep deprivation on cognitive functioning of Adolescents. Through a systematic review, articles based on adolescents of the age group 10-19 years were included in the paper and the effect of sleep manipulation was analysed. Sleep manipulation includes sleep extension, sleep improvement and sleep restriction. It was concluded that sleep disturbance like in the older adults, also affects  psychomotor vigilance tasks in adolescents. It was also concluded that sound and adequate amount of sleep improves memory consolidation. The paper however had only a limited number of participants and thus in the figure researches, a larger sample size can help find a generalised conclusion.

Schoch et al., (2019) has stressed on a unique aspect of cognitive mechanisms related to sleeping and memory consolidation associated with it. The paper has aimed at analysing the effect of dreams on memory consolidation during sleep. The paper stated that collecting dream reports includes waking up subjects from sleep. Through this system, the relationship between dreams and memory consolidation during sleep is studied. The paper included a word-picture association after a night with and without waking up subjects from their sleep. This study concluded that the method of waking up students to check the memory consolidation during sleep is effective as there was effective memory consolidation when dreams were collected during the night. 

According to Klinzing, Niethard & Born, (2019) sleep affects the long-term memory formation and consolidation during sleep. The evidence from neurophysiology and behavioural studies conducted on humans and rodents have shown formation of long-term memory during sleep. Long-term memory is fostered by sleep. The paper has highlighted three features. The paper had discussed that there are thalamic contributions towards memory consolidation during sleep. Spindle activity is linked with sleep-dependent memory enhancement and in humans it occurs during the non-REM sleep stage. The paper has, through the narrative discussion, discussed the idea of dictating use of thalamus in the memory consolidation during sleep. The paper concluded that sleep aids abstraction and schema-like information. This aspect has not been stressed on by Gosselin et al., (2019) and De Bruin et al., (2017).

The Impact of Sleep Deprivation on Cognitive Functioning

Hu et al., (2020) though worked on the memory consolidation during sleep like Klinzing, Niethard & Born, (2019), targeted towards a different aspect. According to the paper discusses Targeted memory reactivation (TMR). It is a method which is employed to conduct manipulation of memory processing during sleep. TMR has a crucial role for sleep-based memory consolidation and resulting neural mechanisms which are affected by sleep deprivation or lesser amount of sleep among adolescents and older adults. The paper has concluded through the involvement of effective sample size, that TMR has the power to influence memory storage during non-rapid-eye-movement sleep. The paper also concluded that this method is useful to understand neurocognitive mechanisms of memory consolidation that occurs during sleep which can be affected by sleep deprivation.

According to Koyanagi et al., (2019) there is an effective relation between adult-born neurons and memory consolidation during sleep. The paper has discussed the missing links that have not been discussed by earlier research papers like that of Klinzing, Niethard & Born, (2019) and Hu, et al., (2020). Koyanagi et al., (2019) discussed past articles to conduct the research. The paper stated that though the functions of sleep are yet to be established effectively in promoting memory consolidation during sleep. Lack of sleep impairs hippocampal-dependent memory and not hippocampal-independent tasks. Sleep deprivation results in significant stress and affects the role played by non-hippocampal brain regions. These aspects are important for cognition. Memories get replayed in the hippocampus during sleep and thus cognitive mechanisms are related to sleeping. 

Just like Koyanagi et al., (2019) discussed hippocampal Contributions towards sleep, Antony & Paller, (2017) also discusses the contribution of Hippocampus in Declarative Memory consolidation that occurs during sleep. Human brain faces information storage challenges when it has to form new useful memories by writing over old ones. Cognitive aspects like memory consolidation takes place effectively during sleep and that has been concluded by the paper by Antony & Paller, (2017). Cognitive psychological models that discuss retrieval have stressed on the role of context on the memory retrieval process. Successful retrieval of a memory occurs when mental context is connected with the situation of the learning process. Thus, role for sleep is effective in stabilizing new declarative memories

Cunningham & Payne, (2017) stated unlike other researches that emotional experiences have a place effectively in an individual's memories. Earlier researches have concluded that emotion causes neurochemical and neurophysiological reactions in individuals and it benefits memory consolidation. The present paper indicates that sleep leads to long-term consolidation of emotional information in memory. The paper has concluded that effective sleep will result in memory development. Emotional experiences affect the critical components of every one’s life narrative. The authors have concluded that REM sleep is important for consolidation of emotional memory. The paper also concluded Slow Wave Sleep (SWS) and REM sleep serves complementary functions and it facilitates emotional memory consolidation during sleep. 

Competition between memories can make memories weak. Memories compete among them during sleep according to Antony et al., (2018) and that weakens the memories. The paper investigated a unique concept like memory competition during sleep by presenting human participants with auditory cues which are related to two distinct picture-location pairs which were presented to the participants during their sleep. Competition during learning was promoted among the participants by manipulating them to rehearse the pictures with similar either competitively or separately. The paper concluded that competition if occurs between memories in an individual during the  learning process, the cognitive ability gets effectively consolidated during sleep.

References

Antony, J. W., & Paller, K. A. (2017). Hippocampal contributions to declarative memory consolidation during sleep. In The hippocampus from cells to systems (pp. 245-280). Springer, Cham.

Antony, J. W., Cheng, L. Y., Brooks, P. P., Paller, K. A., & Norman, K. A. (2018). Competitive learning modulates memory consolidation during sleep. Neurobiology of Learning and Memory, 155, 216-230.

Cunningham, T. J., & Payne, J. D. (2017). Emotional memory consolidation during sleep. Cognitive neuroscience of memory consolidation, 133-159.

De Bruin, E. J., van Run, C., Staaks, J., & Meijer, A. M. (2017). Effects of sleep manipulation on cognitive functioning of adolescents: A systematic review. Sleep medicine reviews, 32, 45-57.

Gosselin, N., Baril, A. A., Osorio, R. S., Kaminska, M., & Carrier, J. (2019). Obstructive sleep apnea and the risk of cognitive decline in older adults. American journal of respiratory and critical care medicine, 199(2), 142-148.

Hu, X., Cheng, L. Y., Chiu, M. H., & Paller, K. A. (2020). Promoting memory consolidation during sleep: A meta-analysis of targeted memory reactivation. Psychological bulletin, 146(3), 218.

Klinzing, J. G., Niethard, N., & Born, J. (2019). Mechanisms of systems memory consolidation during sleep. Nature neuroscience, 22(10), 1598-1610.

Koyanagi, I., Akers, K. G., Vergara, P., Srinivasan, S., Sakurai, T., & Sakaguchi, M. (2019). Memory consolidation during sleep and adult hippocampal neurogenesis. Neural regeneration research, 14(1), 20.

Muehlroth, B. E., Rasch, B., & Werkle-Bergner, M. (2020). Episodic memory consolidation during sleep in healthy aging. Sleep Medicine Reviews, 52, 101304.

Schoch, S. F., Cordi, M. J., Schredl, M., & Rasch, B. (2019). The effect of dream report collection and dream incorporation on memory consolidation during sleep. Journal of sleep research, 28(1), e12754.