The researchers report that a survey of more than 10,000 people over the age of 70 showed that people who slept more than nine hours or less than five hours a day had lower average cognitive levels than those who slept about seven hours a day
Accordingly, the researchers believe that in order to improve the cognitive ability of the elderly, it is necessary to use relevant tools to detect their sleep time, and to intervene in their sleep time to maintain an appropriate amount of sleep time
Those who sleep more than 9 hours or less than 5 hours a day are people over the age of 80.