Nightly sleep duration and next-day reaction time in adolescents: proportional and absolute differences across four tasks

Objective. To estimate how next-day reaction time varies when adolescents' recorded sleep is shorter than usual, and to compare this association across four tasks performed on the same day. Methods. We retrospectively analyzed a 21-day observational panel of 60 participants born in 2008–2010. We examined how nightly sleep duration in the diary export related to next-day mean reaction time (RT) on a brief psychomotor vigilance task (PVT), left–right choice, go/no-go and number comparison. We included participant and date fixed effects and calculated confidence intervals (CIs) with clustering by participant. On days with all four outcomes, we compared the other tasks with the PVT on a proportional scale and, in a post hoc analysis, in milliseconds. Results. Sleep records covered all 1,260 participant-days. All four RT outcomes were available on 1,200 of those days. One hour less recorded sleep than a participant's average was associated with longer mean RT on the PVT (3.52%, 95% CI 2.62–4.42), choice (2.03%, 1.53–2.53), go/no-go (1.82%, 1.30–2.35) and number comparison (1.89%, 1.32–2.47). The PVT showed the largest proportional change in same-day comparisons (joint p = .00021). On complete days, an hour less sleep corresponded to estimated delays of 10.26 ms for the PVT, 9.50 ms for choice, 7.36 ms for go/no-go and 10.44 ms for number comparison. Choice and number-comparison accuracy were lower after shorter nights. Exported sleep time exceeded recorded time in bed on 48 days and matched the current website calculation exactly on only 63 days. Conclusions. Shorter recorded sleep was associated with slower next-day responses on all four tasks. The PVT showed the largest proportional change. In milliseconds, the estimated delays for choice and number comparison were close to the PVT estimate. How the historical software generated the sleep and performance summaries remains uncertain. Correspondence: Zicheng Xia, [email protected]; Xuelu Li, [email protected]. Affiliation: Nanjing Foreign Language School.