Sleep restriction and age effects on distinct aspects of cognition in adolescents.

Insufficient sleep negatively impacts scholastic performance in children and adolescents. Here we use a dose-response time in bed (TIB) restriction study to evaluate associations between sleep loss and multiple aspects of cognition. We evaluated changes in cognitive measures across ages 10 to 23 years and determined whether the effects of sleep loss changed across this age range. A younger cohort (n = 77, age range 9.9 to 16.2 years) was studied annually for 3 years. An older cohort study (n = 82, age range 15 to 22.8 years) was interrupted by the COVID pandemic with 25 participants completing multiple years. Annually participants completed each of three TIB conditions: four consecutive nights with 7, 8.5, or 10 hours in bed. A day of cognitive testing followed the fourth night. Restricting TIB to 7 hours was associated with impaired top-down attentional control and cognitive flexibility, but performance did not differ between 8.5 and 10 hours of TIB conditions. Psychomotor vigilance test performance decreased as TIB was restricted from 10 to 8.5 hours and decreased further with restriction to 7 hours. Sternberg test measures of working memory were not significantly affected by TIB restriction. The effects of sleep loss on these cognitive measures did not change significantly with age, but age-related improvement in many of the measures may compensate for some sleep loss effects. The findings here do not indicate an adolescent decrease in sleep need; however, the minimal duration of sleep needed for optimal performance appears to differ depending on the cognitive measure.