Researchers from Imperial College London conducted a study on the sleep patterns of over 26,000 UK adults to investigate how sleep duration and quality affect cognitive abilities. The study used data from the UK Biobank database and discovered that individuals who are night owls tend to perform better in cognitive tests compared to those who are morning larks.
Lead author Dr. Raha West noted that these sleep preferences, known as chronotypes, may have an impact on cognitive function. The study revealed that getting seven to nine hours of sleep each night is ideal for optimal brain function, enhancing memory, reasoning, and information processing speed. Sleeping less than seven hours or more than nine hours can negatively affect cognitive performance.
In general, quality sleep is essential for brain function regardless of whether you are a night owl or a morning lark. However, the researchers observed a significant difference in cognitive performance between different chronotypes. Night owls consistently outperformed morning larks in cognitive tests, with evening types scoring 13.5% higher in one group and 7.5% higher in another. Even intermediate sleepers, who do not have a strong preference, scored between 6.3% and 10.6% higher than morning types.
These differences in cognitive performance remained significant even after accounting for factors such as age, gender, lifestyle habits, and chronic diseases. Younger and healthier individuals generally performed better on cognitive tests, as expected.
Dr. West emphasized that the study’s findings do not mean all morning people have worse cognitive performance. Instead, it highlights a trend where evening types may have better cognition overall. The research suggests that aligning with your natural sleep tendencies can benefit cognitive health. Making small adjustments to your sleep habits, such as adjusting bedtime, increasing exposure to evening light, and maintaining a consistent sleep schedule, can enhance cognitive function.
While shifting from a morning to an evening chronotype may be challenging, finding your optimal bedtime hours is key. Previous studies have shown that sleep traits are heritable, emphasizing the importance of managing sleep patterns for brain function.
Co-author Professor Daqing Ma stressed the direct impact of sleep duration on brain function and called for policy interventions to improve sleep patterns in the general population. The study, published in the journal BMJ Public Health, also highlighted that insomnia did not significantly impair cognitive performance, indicating a need for further research on insomnia’s specific aspects.
