New research suggests that even a small increase in sleep duration can have a positive impact on cognitive abilities in young people. The study, involving 3,222 adolescents aged 9 to 14, found that those with slightly better sleep habits (averaging 7 hours, 25 minutes per night) showed noticeable improvements in reading, problem-solving, and focus compared to those with the worst sleep habits (averaging 7 hours, 10 minutes). While there was little difference in academic achievement between the groups, the cognitive benefits of even 15 extra minutes of sleep highlight the importance of sleep quality for adolescent brain development.
“Even though the differences in the amount of sleep that each group got was relatively small, at just over a quarter-of-an-hour between the best and worst sleepers, we could still see differences in brain structure and activity and in how well they did at tasks,” says clinical neuropsychologist Barbara Sahakian from the University of Cambridge.
“This drives home to us just how important it is to have a good night’s sleep at this important time in life.”
First author Dr Qing Ma from Fudan University said: “Although our study can’t answer conclusively whether young people have better brain function and perform better at tests because they sleep better, there are a number of studies that would support this idea. For example, research has shown the benefits of sleep on memory, especially on memory consolidation, which is important for learning.”
The researchers also assessed the participants’ heart rates, finding that Group Three had the lowest heart rates across the sleep states and Group One the highest. Lower heart rates are usually a sign of better health, whereas higher rates often accompany poor sleep quality like restless sleep, frequent awakenings and excessive daytime sleepiness.