Many individuals experience sleep interruptions, consequently negatively affecting their daytime cognitive function. Sleep interruptions occur when the amount of sleep is inadequate in order to support attentiveness, functioning, and the health of individuals (Richards & Pao, 2014). Sleep interruptions occur when an individual’s sleep cycle is disrupted multiple times throughout the night, these interruptions lead to insufficient sleep. Interrupted sleep, also known as fragmented sleep or disrupted sleep, contributes to insomnia and sleep deprivation, which both produce various negative effects (Suni & Wright, 2022). The recommended amount of sleep for young adults and adults is 7 to 9 hours each night (Hirshkowitz et al., 2015). Consequently, individuals sleeping less than 7 hours a night may experience adverse effects, such as compromised functioning (Watson et al., 2015). The ideal amount of sleep has been recognized to be 7.16 hours per night in order to achieve the best cognitive performance (Wild et al., 2018). Furthermore, individuals who acquire less than the optimal amount of sleep, between 7 and 8 hours nightly, experience noticeable impairments to their cognitive functioning (Wild et al., 2018).
There are various studies to suggest that sleep deprivation and daytime cognitive performance is correlated, and have a negative impact on the latter. It is known that the human frontal lobes are vulnerable to sleep deprivation. This is demonstrated in a study done by Verweij et al., (2014), which followed eight subjects during a day after normal sleep and during a day following total sleep deprivation. The findings of their studies concluded that the functional connectivity of prefrontal cortical areas was most strongly affected by sleep deprivation. These results confirm findings from previous studies, that have shown sleep deprivation to greatly affect cognitive functions (such as working memory) mediated by the prefrontal cortex (Verweij et al., 2014).
We will outline a study designed to demonstrate the negative effect sleep interruption has on daytime cognitive function to prove that sleep interruption does not enhance daytime cognitive function. The appropriate study population for this research will include undergraduate university students in their first to fourth year. The inclusion criteria for this population will include individuals that regularly sleep 7-9 hr per night. They must also be nonsmokers and consume 3 or fewer cups of coffee per day (or equivalent to <300 mg of caffeine). The exclusion criteria includes individuals with a history of sleep disorders, failing a toxicology screen for stimulants or recreational drugs, and a history of chronic pain (pain lasting >6 months). The study is designed as a randomized control study and should be conducted in an inpatient clinical research suite.
The purpose of this controlled study is to test whether sleep interruption has an impact on daytime cognitive abilities. It will also evaluate how sleep loss due to disruption versus loss due to restriction impacts cognitive function. The study takes place over 5 nights. Night 1 will serve as the baseline; all subjects will be allowed an 8-hour undisturbed sleep opportunity. Once the baseline is set on night 1, all healthy subjects are randomly assigned to one of three groups: the control group (8 hours of uninterrupted sleep), the Forced Awakening group, and the Restricted Sleep Opportunity group. The study will examine the prevalence of sleep interruption and its impact on daytime cognitive function. Each participant will complete two tests designed to measure aspects of cognitive function during the day. Cognitive ability will be operationalized using two cognitive function tests that will assess attention, reaction time, and memory. The case-control study enables researchers to obtain findings that provide temporal evidence that sleep disturbance does negatively impact cognitive function.
