Sleep's Importance in Cognitive Tasks

 On average, a person spends a third of their life sleeping. From extensive research, we know that the brain is anything but inactive during sleep, as it works as a repair mechanism that is essential for maintaining mental and physical health. Despite this, a large amount of the population suffers from not having adequate sleep and therefore faces drawbacks in their daily lives such as poor cognitive performance and memory deficits. Hence, understanding the effects of sleep on the brain’s ability to recall and perform at optimum levels is a widely researched topic in neuroscience and medicine.

The University of Birmingham conducted a study that aimed to compare the individual performances of “night owls” to those who prefer to start their days early, called “morning larks”. To follow the neurological differences, the brains from the two groups were monitored by an fMRI. Specifically, the resting states of the individuals’ brains were monitored. The test was conducted by following 38 human test subjects who were grouped in either the early or late sleep cycles. By comparing the reaction time, attention levels and self-reported sleepiness throughout the day, researchers were able to conclude that the morning larks were experiencing higher cognitive functionality compared to the night owls. This was further confirmed by fMRI scans which showed that within the early sleep schedule group, there was a stronger connectivity between the medial prefrontal cortex and the posterior cingulate cortex of the brain. Therefore, higher cognitive performance and functional connectivity is found to be correlated to an early sleep schedule. The motivation of this research was to gain a better understanding of the effects of sleep and how external factors such as daily schedules can affect it.

The presentation given by Dr. Eitan showcased a clinical review called “State of the art on targeted memory reactivation: Sleep your way to enhanced cognition”. This study focused on the benefits of sleep when it comes to improving memory reactivation as sleep allows for memory consolidation. Furthermore, Dr. Eitan highlighted that cues given during sleep also prove to be beneficial in memory consolidation. It is suggested by the researchers that the reason sleep has this effect is due to the fact that it allows for hippocampal replay, where the neurons that are fired during a task are reactivated during sleep. Therefore, sleep is important to ensure that the brain can function at a high level when performing cognitive tasks such as recalling information. This research can prove to be especially useful for students who are constantly tasked with storing huge chunks of information and recalling it during exams.

         It can be concluded from both the studies that not only is sleep crucial for cognitive performance, but so is the timing of sleep. Hence, from looking at both studies, it can be argued  that for a population to perform to the best of their cognitive abilities, individuals must get an adequate amount of sleep to ensure hippocampal replay and memory consolidation. Furthermore, they must sleep early as well, so that there is stronger functional connectivity within the regions of the brain responsible for cognitive performance. It should be noted that this information in some ways stands to be contradictory and, in some ways, supportive of school timings. On one hand, traditional, early start timings of schools and corporate jobs allow for people to have an early sleep cycle schedule. However, this may also mean that individuals will get less sleep, especially students, as they are tasked with studying that can often go late into nights.  This means that the quality and duration of sleep may be affected, which will lead to cognitive deficits and poorer performance. Further research regarding sleep is needed. Perhaps, even restructuring of our institutions for the advancement of society through maximizing the benefits that come with experiencing optimum sleep.

University of Birmingham (2019, February 16). Brain Connections that Disadvantage Night Owls Revealed. NeuroscienceNews. Retrieved December 11, 2019 from

http://neurosciencenews.com/night-owl-brain-connections-10752/

Schouten, Daphne I., et al. “State of the Art on Targeted Memory Reactivation:

Sleep Your Way to Enhanced Cognition.” Sleep Medicine Reviews, vol. 32, 2017, pp. 123–131., doi:10.1016/j.smrv.2016.04.002.