Non-Linear Effects of Sleep Duration on Cognitive Alertness in Adolescents: An Observational Study

Yahia Asfour

Abstract: This study investigates the relationship between sleep duration and cognitive alertness in male adolescents using naturalistic daily measurements. Participants completed online Corsi Block-Tapping and Stroop tasks, with performance aggregated into a composite cognitive coefficient. Spearman correlation and regression analyses indicated a moderate overall association between sleep duration and cognitive performance, with stronger correlations observed when excessive sleep durations were excluded. Binned analysis suggested an optimal performance range around 9?10 hours of sleep. The findings support a non-linear relationship between sleep duration and alertness, highlighting diminishing returns beyond an optimal threshold and demonstrating the feasibility of scalable online cognitive assessment methods.

Keywords: Adolescent sleep, cognitive performance, working memory, executive function, sleep duration optimisation, behavioural analytics