We often hear about people suffering from insomnia or sleep deprivation, but oversleeping also appears to have many side-effects. Sleep plays an important role in life as much as oxygen, water and food for survival. It is known that sleep impacts the body and psychological well-being of a person, which have been highlighted in many sleep-studies.
According to a study published in ‘Wiley Interdisciplinary Reviews: Cognitive Science in 2010’, sleep plays a major role in the consolidation of recollecting memories and also helps in insightful and reasonable thinking.
Sleep also have phases which might be physiologically and neurochemically different, like rapid eye movement (REM) and non-rapid eye movement (non-REM) sleep. These phases are followed by an advanced transformation in the patterns of neural activity and releasing neurotransmitters, which balances the release of hormones moderated by the lateral and posterior hypothalamus. The hormones include histamine, norepinephrine, serotonin and acetylcholine.
The changes in neurological functioning while sleeping shows to have massive effects on mood, memory and cognition. A study published in JAMA Network Open revealed the link between sleep and cognitive function, and the amount of sleep required per day for an optimal cognitive performance.
The team analysed the date collected from two random groups of participants comprising 28,756 individuals, in which some are living in England and are 50 years or older, while the others are living in China who are 45 years or above. The participants were accumulated from the English Longitudinal Study of Ageing (ELSA) and the China Health and Retirement Longitudinal Study (CHARLS) between 2008 and 2017 approximately.
The study was finalised on the readings based on about 20,065 participants (9,254 from ELSA and 10,811 from CHARLS). The sleep duration was self-reported by the members, while the cognitive evaluation was conducted in the form of questionnaires to examine memory, executive performance and orientation.
The researchers observed that people who slept four hours or less every night experienced a quicker cognitive decline. They also found a similar speed of cognitive decline among the participants who slept 10 hours or more every night. This signifies that both, sleeping too much and sleeping too little, are statistically associated with quicker cognitive decline.
The study also indicated that an average sleep duration of seven hours per night is the ideal amount of sleep duration.