How much of the time individuals over 55 spend in bed is actually spent sleeping? This aspect of sleep appears to have a significant connection with certain cognitive skills, according to recent research by KU Leuven and UGent. Participants who spent a larger portion of their time in bed actually sleeping scored better on tasks requiring concentration, planning, and flexible switching. Contrary to previous assumptions, the researchers found no clear link between the total number of sleep hours and these specific cognitive functions.
Often, the emphasis is placed on the number of hours spent in bed, but sleep efficiency – the percentage of time in bed that one is actually asleep – provides a more accurate picture of sleep quality. Higher sleep efficiency means less time spent awake and worrying in bed.
For the study, 233 Flemish participants aged between 55 and 90 were surveyed. They wore a motion sensor on their wrist for a week to measure their sleep duration and efficiency, kept sleep diaries, and completed a series of cognitive tests. The results showed a consistent correlation: participants with higher sleep efficiency performed better on tests measuring executive functions. These functions include the ability to plan actions, control impulses, and switch between different tasks. This link remained significant even after accounting for factors such as age, education level, and physical activity.
The researchers emphasize the importance of looking beyond just the number of sleep hours. Sleep efficiency plays a crucial role in understanding the relationship between sleep and cognitive performance. However, the study indicates a correlation, not a causal relationship; it does not prove that improved sleep efficiency directly leads to better cognitive skills. The participants were generally relatively healthy, meaning the results may not be directly generalizable to individuals with severe sleep or cognitive problems.
While sleep duration in this study did not show a direct link to better cognitive skills, sufficient sleep remains essential. Good sleep hygiene is recommended to improve sleep quality. Recommendations include regular daytime physical activity, avoiding prolonged wakefulness in bed by engaging in quiet activities outside the bedroom, and creating a dark, quiet bedroom primarily associated with sleep. Maintaining a consistent daily wake-up time and seeking professional help for persistent sleep problems, such as cognitive behavioral therapy for insomnia, are also advised.
